common/hush.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * sh.c -- a prototype Bourne shell grammar parser
   4  *      Intended to follow the original Thompson and Ritchie
   5  *      "small and simple is beautiful" philosophy, which
   6  *      incidentally is a good match to today's BusyBox.
   7  *
   8  * Copyright (C) 2000,2001  Larry Doolittle  <larry@doolittle.boa.org>
   9  *
  10  * Credits:
  11  *      The parser routines proper are all original material, first
  12  *      written Dec 2000 and Jan 2001 by Larry Doolittle.
  13  *      The execution engine, the builtins, and much of the underlying
  14  *      support has been adapted from busybox-0.49pre's lash,
  15  *      which is Copyright (C) 2000 by Lineo, Inc., and
  16  *      written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>.
  17  *      That, in turn, is based in part on ladsh.c, by Michael K. Johnson and
  18  *      Erik W. Troan, which they placed in the public domain.  I don't know
  19  *      how much of the Johnson/Troan code has survived the repeated rewrites.
  20  * Other credits:
  21  *      simple_itoa() was lifted from boa-0.93.15
  22  *      b_addchr() derived from similar w_addchar function in glibc-2.2
  23  *      setup_redirect(), redirect_opt_num(), and big chunks of main()
  24  *        and many builtins derived from contributions by Erik Andersen
  25  *      miscellaneous bugfixes from Matt Kraai
  26  *
  27  * There are two big (and related) architecture differences between
  28  * this parser and the lash parser.  One is that this version is
  29  * actually designed from the ground up to understand nearly all
  30  * of the Bourne grammar.  The second, consequential change is that
  31  * the parser and input reader have been turned inside out.  Now,
  32  * the parser is in control, and asks for input as needed.  The old
  33  * way had the input reader in control, and it asked for parsing to
  34  * take place as needed.  The new way makes it much easier to properly
  35  * handle the recursion implicit in the various substitutions, especially
  36  * across continuation lines.
  37  *
  38  * Bash grammar not implemented: (how many of these were in original sh?)
  39  *      $@ (those sure look like weird quoting rules)
  40  *      $_
  41  *      ! negation operator for pipes
  42  *      &> and >& redirection of stdout+stderr
  43  *      Brace Expansion
  44  *      Tilde Expansion
  45  *      fancy forms of Parameter Expansion
  46  *      aliases
  47  *      Arithmetic Expansion
  48  *      <(list) and >(list) Process Substitution
  49  *      reserved words: case, esac, select, function
  50  *      Here Documents ( << word )
  51  *      Functions
  52  * Major bugs:
  53  *      job handling woefully incomplete and buggy
  54  *      reserved word execution woefully incomplete and buggy
  55  * to-do:
  56  *      port selected bugfixes from post-0.49 busybox lash - done?
  57  *      finish implementing reserved words: for, while, until, do, done
  58  *      change { and } from special chars to reserved words
  59  *      builtins: break, continue, eval, return, set, trap, ulimit
  60  *      test magic exec
  61  *      handle children going into background
  62  *      clean up recognition of null pipes
  63  *      check setting of global_argc and global_argv
  64  *      control-C handling, probably with longjmp
  65  *      follow IFS rules more precisely, including update semantics
  66  *      figure out what to do with backslash-newline
  67  *      explain why we use signal instead of sigaction
  68  *      propagate syntax errors, die on resource errors?
  69  *      continuation lines, both explicit and implicit - done?
  70  *      memory leak finding and plugging - done?
  71  *      more testing, especially quoting rules and redirection
  72  *      document how quoting rules not precisely followed for variable assignments
  73  *      maybe change map[] to use 2-bit entries
  74  *      (eventually) remove all the printf's
  75  *
  76  * This program is free software; you can redistribute it and/or modify
  77  * it under the terms of the GNU General Public License as published by
  78  * the Free Software Foundation; either version 2 of the License, or
  79  * (at your option) any later version.
  80  *
  81  * This program is distributed in the hope that it will be useful,
  82  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  83  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  84  * General Public License for more details.
  85  *
  86  * You should have received a copy of the GNU General Public License
  87  * along with this program; if not, write to the Free Software
  88  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  89  */
  90 #define __U_BOOT__
  91 #ifdef __U_BOOT__
  92 #include <malloc.h>         /* malloc, free, realloc*/
  93 #include <linux/ctype.h>    /* isalpha, isdigit */
  94 #include <common.h>        /* readline */
  95 #include <hush.h>
  96 #include <command.h>        /* find_cmd */
  97 #include <cmd_bootm.h>      /* do_bootd */
  98 #endif
  99 #ifdef CFG_HUSH_PARSER
 100 #ifndef __U_BOOT__
 101 #include <ctype.h>     /* isalpha, isdigit */
 102 #include <unistd.h>    /* getpid */
 103 #include <stdlib.h>    /* getenv, atoi */
 104 #include <string.h>    /* strchr */
 105 #include <stdio.h>     /* popen etc. */
 106 #include <glob.h>      /* glob, of course */
 107 #include <stdarg.h>    /* va_list */
 108 #include <errno.h>
 109 #include <fcntl.h>
 110 #include <getopt.h>    /* should be pretty obvious */
 111
 112 #include <sys/stat.h>  /* ulimit */
 113 #include <sys/types.h>
 114 #include <sys/wait.h>
 115 #include <signal.h>
 116
 117 /* #include <dmalloc.h> */
 118 /* #define DEBUG_SHELL */
 119
 120 #if 1
 121 #include "busybox.h"
 122 #include "cmdedit.h"
 123 #else
 124 #define applet_name "hush"
 125 #include "standalone.h"
 126 #define hush_main main
 127 #undef CONFIG_FEATURE_SH_FANCY_PROMPT
 128 #define BB_BANNER
 129 #endif
 130 #endif
 131 #define SPECIAL_VAR_SYMBOL 03
 132 #ifndef __U_BOOT__
 133 #define FLAG_EXIT_FROM_LOOP 1
 134 #define FLAG_PARSE_SEMICOLON (1 << 1)           /* symbol ';' is special for parser */
 135 #define FLAG_REPARSING       (1 << 2)           /* >= 2nd pass */
 136
 137 #endif
 138
 139 #ifdef __U_BOOT__
 140 #define EXIT_SUCCESS 0
 141 #define EOF -1
 142 #define syntax() syntax_err()
 143 #define xstrdup strdup
 144 #define error_msg printf
 145 #else
 146 typedef enum {
 147         REDIRECT_INPUT     = 1,
 148         REDIRECT_OVERWRITE = 2,
 149         REDIRECT_APPEND    = 3,
 150         REDIRECT_HEREIS    = 4,
 151         REDIRECT_IO        = 5
 152 } redir_type;
 153
 154 /* The descrip member of this structure is only used to make debugging
 155  * output pretty */
 156 struct {int mode; int default_fd; char *descrip;} redir_table[] = {
 157         { 0,                         0, "()" },
 158         { O_RDONLY,                  0, "<"  },
 159         { O_CREAT|O_TRUNC|O_WRONLY,  1, ">"  },
 160         { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
 161         { O_RDONLY,                 -1, "<<" },
 162         { O_RDWR,                    1, "<>" }
 163 };
 164 #endif
 165
 166 typedef enum {
 167         PIPE_SEQ = 1,
 168         PIPE_AND = 2,
 169         PIPE_OR  = 3,
 170         PIPE_BG  = 4,
 171 } pipe_style;
 172
 173 /* might eventually control execution */
 174 typedef enum {
 175         RES_NONE  = 0,
 176         RES_IF    = 1,
 177         RES_THEN  = 2,
 178         RES_ELIF  = 3,
 179         RES_ELSE  = 4,
 180         RES_FI    = 5,
 181         RES_FOR   = 6,
 182         RES_WHILE = 7,
 183         RES_UNTIL = 8,
 184         RES_DO    = 9,
 185         RES_DONE  = 10,
 186         RES_XXXX  = 11,
 187         RES_IN    = 12,
 188         RES_SNTX  = 13
 189 } reserved_style;
 190 #define FLAG_END   (1<<RES_NONE)
 191 #define FLAG_IF    (1<<RES_IF)
 192 #define FLAG_THEN  (1<<RES_THEN)
 193 #define FLAG_ELIF  (1<<RES_ELIF)
 194 #define FLAG_ELSE  (1<<RES_ELSE)
 195 #define FLAG_FI    (1<<RES_FI)
 196 #define FLAG_FOR   (1<<RES_FOR)
 197 #define FLAG_WHILE (1<<RES_WHILE)
 198 #define FLAG_UNTIL (1<<RES_UNTIL)
 199 #define FLAG_DO    (1<<RES_DO)
 200 #define FLAG_DONE  (1<<RES_DONE)
 201 #define FLAG_IN    (1<<RES_IN)
 202 #define FLAG_START (1<<RES_XXXX)
 203
 204 /* This holds pointers to the various results of parsing */
 205 struct p_context {
 206         struct child_prog *child;
 207         struct pipe *list_head;
 208         struct pipe *pipe;
 209 #ifndef __U_BOOT__
 210         struct redir_struct *pending_redirect;
 211 #endif
 212         reserved_style w;
 213         int old_flag;                           /* for figuring out valid reserved words */
 214         struct p_context *stack;
 215         int type;                       /* define type of parser : ";$" common or special symbol */
 216         /* How about quoting status? */
 217 };
 218
 219 #ifndef __U_BOOT__
 220 struct redir_struct {
 221         redir_type type;                        /* type of redirection */
 222         int fd;                                         /* file descriptor being redirected */
 223         int dup;                                        /* -1, or file descriptor being duplicated */
 224         struct redir_struct *next;      /* pointer to the next redirect in the list */
 225         glob_t word;                            /* *word.gl_pathv is the filename */
 226 };
 227 #endif
 228
 229 struct child_prog {
 230 #ifndef __U_BOOT__
 231         pid_t pid;                                      /* 0 if exited */
 232 #endif
 233         char **argv;                            /* program name and arguments */
 234 #ifdef __U_BOOT__
 235         int    argc;                            /* number of program arguments */
 236 #endif
 237         struct pipe *group;                     /* if non-NULL, first in group or subshell */
 238 #ifndef __U_BOOT__
 239         int subshell;                           /* flag, non-zero if group must be forked */
 240         struct redir_struct *redirects; /* I/O redirections */
 241         glob_t glob_result;                     /* result of parameter globbing */
 242         int is_stopped;                         /* is the program currently running? */
 243         struct pipe *family;            /* pointer back to the child's parent pipe */
 244 #endif
 245         int sp;                         /* number of SPECIAL_VAR_SYMBOL */
 246         int type;
 247 };
 248
 249 struct pipe {
 250 #ifndef __U_BOOT__
 251         int jobid;                                      /* job number */
 252 #endif
 253         int num_progs;                          /* total number of programs in job */
 254 #ifndef __U_BOOT__
 255         int running_progs;                      /* number of programs running */
 256         char *text;                                     /* name of job */
 257         char *cmdbuf;                           /* buffer various argv's point into */
 258         pid_t pgrp;                                     /* process group ID for the job */
 259 #endif
 260         struct child_prog *progs;       /* array of commands in pipe */
 261         struct pipe *next;                      /* to track background commands */
 262 #ifndef __U_BOOT__
 263         int stopped_progs;                      /* number of programs alive, but stopped */
 264         int job_context;                        /* bitmask defining current context */
 265 #endif
 266         pipe_style followup;            /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
 267         reserved_style r_mode;          /* supports if, for, while, until */
 268 };
 269
 270 #ifndef __U_BOOT__
 271 struct close_me {
 272         int fd;
 273         struct close_me *next;
 274 };
 275 #endif
 276
 277 struct variables {
 278         char *name;
 279         char *value;
 280         int flg_export;
 281         int flg_read_only;
 282         struct variables *next;
 283 };
 284
 285 /* globals, connect us to the outside world
 286  * the first three support $?, $#, and $1 */
 287 #ifndef __U_BOOT__
 288 char **global_argv;
 289 unsigned int global_argc;
 290 #endif
 291 unsigned int last_return_code;
 292 #ifndef __U_BOOT__
 293 extern char **environ; /* This is in <unistd.h>, but protected with __USE_GNU */
 294 #endif
 295
 296 /* "globals" within this file */
 297 static char *ifs;
 298 static char map[256];
 299 #ifndef __U_BOOT__
 300 static int fake_mode;
 301 static int interactive;
 302 static struct close_me *close_me_head;
 303 static const char *cwd;
 304 static struct pipe *job_list;
 305 static unsigned int last_bg_pid;
 306 static unsigned int last_jobid;
 307 static unsigned int shell_terminal;
 308 static char *PS1;
 309 static char *PS2;
 310 struct variables shell_ver = { "HUSH_VERSION", "0.01", 1, 1, 0 };
 311 struct variables *top_vars = &shell_ver;
 312 #else
 313 static int flag_repeat = 0;
 314 static int do_repeat = 0;
 315 static struct variables *top_vars ;
 316 #endif /*__U_BOOT__ */
 317
 318 #define B_CHUNK (100)
 319 #define B_NOSPAC 1
 320
 321 typedef struct {
 322         char *data;
 323         int length;
 324         int maxlen;
 325         int quote;
 326         int nonnull;
 327 } o_string;
 328 #define NULL_O_STRING {NULL,0,0,0,0}
 329 /* used for initialization:
 330         o_string foo = NULL_O_STRING; */
 331
 332 /* I can almost use ordinary FILE *.  Is open_memstream() universally
 333  * available?  Where is it documented? */
 334 struct in_str {
 335         const char *p;
 336 #ifndef __U_BOOT__
 337         char peek_buf[2];
 338 #endif
 339         int __promptme;
 340         int promptmode;
 341 #ifndef __U_BOOT__
 342         FILE *file;
 343 #endif
 344         int (*get) (struct in_str *);
 345         int (*peek) (struct in_str *);
 346 };
 347 #define b_getch(input) ((input)->get(input))
 348 #define b_peek(input) ((input)->peek(input))
 349
 350 #ifndef __U_BOOT__
 351 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
 352
 353 struct built_in_command {
 354         char *cmd;                                      /* name */
 355         char *descr;                            /* description */
 356         int (*function) (struct child_prog *);  /* function ptr */
 357 };
 358 #endif
 359
 360 /* This should be in utility.c */
 361 #ifdef DEBUG_SHELL
 362 #ifndef __U_BOOT__
 363 static void debug_printf(const char *format, ...)
 364 {
 365         va_list args;
 366         va_start(args, format);
 367         vfprintf(stderr, format, args);
 368         va_end(args);
 369 }
 370 #else
 371 #define debug_printf printf             /* U-Boot debug flag */
 372 #endif
 373 #else
 374 static inline void debug_printf(const char *format, ...) { }
 375 #endif
 376 #define final_printf debug_printf
 377
 378 #ifdef __U_BOOT__
 379 static void syntax_err(void) {
 380          printf("syntax error\n");
 381 }
 382 #else
 383 static void __syntax(char *file, int line) {
 384         error_msg("syntax error %s:%d", file, line);
 385 }
 386 #define syntax() __syntax(__FILE__, __LINE__)
 387 #endif
 388
 389 #ifdef __U_BOOT__
 390 static void *xmalloc(size_t size);
 391 static void *xrealloc(void *ptr, size_t size);
 392 #else
 393 /* Index of subroutines: */
 394 /*   function prototypes for builtins */
 395 static int builtin_cd(struct child_prog *child);
 396 static int builtin_env(struct child_prog *child);
 397 static int builtin_eval(struct child_prog *child);
 398 static int builtin_exec(struct child_prog *child);
 399 static int builtin_exit(struct child_prog *child);
 400 static int builtin_export(struct child_prog *child);
 401 static int builtin_fg_bg(struct child_prog *child);
 402 static int builtin_help(struct child_prog *child);
 403 static int builtin_jobs(struct child_prog *child);
 404 static int builtin_pwd(struct child_prog *child);
 405 static int builtin_read(struct child_prog *child);
 406 static int builtin_set(struct child_prog *child);
 407 static int builtin_shift(struct child_prog *child);
 408 static int builtin_source(struct child_prog *child);
 409 static int builtin_umask(struct child_prog *child);
 410 static int builtin_unset(struct child_prog *child);
 411 static int builtin_not_written(struct child_prog *child);
 412 #endif
 413 /*   o_string manipulation: */
 414 static int b_check_space(o_string *o, int len);
 415 static int b_addchr(o_string *o, int ch);
 416 static void b_reset(o_string *o);
 417 static int b_addqchr(o_string *o, int ch, int quote);
 418 static int b_adduint(o_string *o, unsigned int i);
 419 /*  in_str manipulations: */
 420 static int static_get(struct in_str *i);
 421 static int static_peek(struct in_str *i);
 422 static int file_get(struct in_str *i);
 423 static int file_peek(struct in_str *i);
 424 #ifndef __U_BOOT__
 425 static void setup_file_in_str(struct in_str *i, FILE *f);
 426 #else
 427 static void setup_file_in_str(struct in_str *i);
 428 #endif
 429 static void setup_string_in_str(struct in_str *i, const char *s);
 430 #ifndef __U_BOOT__
 431 /*  close_me manipulations: */
 432 static void mark_open(int fd);
 433 static void mark_closed(int fd);
 434 static void close_all(void);
 435 #endif
 436 /*  "run" the final data structures: */
 437 static char *indenter(int i);
 438 static int free_pipe_list(struct pipe *head, int indent);
 439 static int free_pipe(struct pipe *pi, int indent);
 440 /*  really run the final data structures: */
 441 #ifndef __U_BOOT__
 442 static int setup_redirects(struct child_prog *prog, int squirrel[]);
 443 #endif
 444 static int run_list_real(struct pipe *pi);
 445 #ifndef __U_BOOT__
 446 static void pseudo_exec(struct child_prog *child) __attribute__ ((noreturn));
 447 #endif
 448 static int run_pipe_real(struct pipe *pi);
 449 /*   extended glob support: */
 450 #ifndef __U_BOOT__
 451 static int globhack(const char *src, int flags, glob_t *pglob);
 452 static int glob_needed(const char *s);
 453 static int xglob(o_string *dest, int flags, glob_t *pglob);
 454 #endif
 455 /*   variable assignment: */
 456 static int is_assignment(const char *s);
 457 /*   data structure manipulation: */
 458 #ifndef __U_BOOT__
 459 static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
 460 #endif
 461 static void initialize_context(struct p_context *ctx);
 462 static int done_word(o_string *dest, struct p_context *ctx);
 463 static int done_command(struct p_context *ctx);
 464 static int done_pipe(struct p_context *ctx, pipe_style type);
 465 /*   primary string parsing: */
 466 #ifndef __U_BOOT__
 467 static int redirect_dup_num(struct in_str *input);
 468 static int redirect_opt_num(o_string *o);
 469 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end);
 470 static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch);
 471 #endif
 472 static char *lookup_param(char *src);
 473 static char *make_string(char **inp);
 474 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input);
 475 #ifndef __U_BOOT__
 476 static int parse_string(o_string *dest, struct p_context *ctx, const char *src);
 477 #endif
 478 static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, int end_trigger);
 479 /*   setup: */
 480 static int parse_stream_outer(struct in_str *inp, int flag);
 481 #ifndef __U_BOOT__
 482 static int parse_string_outer(const char *s, int flag);
 483 static int parse_file_outer(FILE *f);
 484 #endif
 485 #ifndef __U_BOOT__
 486 /*   job management: */
 487 static int checkjobs(struct pipe* fg_pipe);
 488 static void insert_bg_job(struct pipe *pi);
 489 static void remove_bg_job(struct pipe *pi);
 490 #endif
 491 /*     local variable support */
 492 static char **make_list_in(char **inp, char *name);
 493 static char *insert_var_value(char *inp);
 494 static char *get_local_var(const char *var);
 495 #ifndef __U_BOOT__
 496 static void  unset_local_var(const char *name);
 497 #endif
 498 static int set_local_var(const char *s, int flg_export);
 499
 500 #ifndef __U_BOOT__
 501 /* Table of built-in functions.  They can be forked or not, depending on
 502  * context: within pipes, they fork.  As simple commands, they do not.
 503  * When used in non-forking context, they can change global variables
 504  * in the parent shell process.  If forked, of course they can not.
 505  * For example, 'unset foo | whatever' will parse and run, but foo will
 506  * still be set at the end. */
 507 static struct built_in_command bltins[] = {
 508         {"bg", "Resume a job in the background", builtin_fg_bg},
 509         {"break", "Exit for, while or until loop", builtin_not_written},
 510         {"cd", "Change working directory", builtin_cd},
 511         {"continue", "Continue for, while or until loop", builtin_not_written},
 512         {"env", "Print all environment variables", builtin_env},
 513         {"eval", "Construct and run shell command", builtin_eval},
 514         {"exec", "Exec command, replacing this shell with the exec'd process",
 515                 builtin_exec},
 516         {"exit", "Exit from shell()", builtin_exit},
 517         {"export", "Set environment variable", builtin_export},
 518         {"fg", "Bring job into the foreground", builtin_fg_bg},
 519         {"jobs", "Lists the active jobs", builtin_jobs},
 520         {"pwd", "Print current directory", builtin_pwd},
 521         {"read", "Input environment variable", builtin_read},
 522         {"return", "Return from a function", builtin_not_written},
 523         {"set", "Set/unset shell local variables", builtin_set},
 524         {"shift", "Shift positional parameters", builtin_shift},
 525         {"trap", "Trap signals", builtin_not_written},
 526         {"ulimit","Controls resource limits", builtin_not_written},
 527         {"umask","Sets file creation mask", builtin_umask},
 528         {"unset", "Unset environment variable", builtin_unset},
 529         {".", "Source-in and run commands in a file", builtin_source},
 530         {"help", "List shell built-in commands", builtin_help},
 531         {NULL, NULL, NULL}
 532 };
 533
 534 static const char *set_cwd(void)
 535 {
 536         if(cwd==unknown)
 537                 cwd = NULL;     /* xgetcwd(arg) called free(arg) */
 538         cwd = xgetcwd((char *)cwd);
 539         if (!cwd)
 540                 cwd = unknown;
 541         return cwd;
 542 }
 543
 544 /* built-in 'eval' handler */
 545 static int builtin_eval(struct child_prog *child)
 546 {
 547         char *str = NULL;
 548         int rcode = EXIT_SUCCESS;
 549
 550         if (child->argv[1]) {
 551                 str = make_string(child->argv + 1);
 552                 parse_string_outer(str, FLAG_EXIT_FROM_LOOP |
 553                                         FLAG_PARSE_SEMICOLON);
 554                 free(str);
 555                 rcode = last_return_code;
 556         }
 557         return rcode;
 558 }
 559
 560 /* built-in 'cd <path>' handler */
 561 static int builtin_cd(struct child_prog *child)
 562 {
 563         char *newdir;
 564         if (child->argv[1] == NULL)
 565                 newdir = getenv("HOME");
 566         else
 567                 newdir = child->argv[1];
 568         if (chdir(newdir)) {
 569                 printf("cd: %s: %s\n", newdir, strerror(errno));
 570                 return EXIT_FAILURE;
 571         }
 572         set_cwd();
 573         return EXIT_SUCCESS;
 574 }
 575
 576 /* built-in 'env' handler */
 577 static int builtin_env(struct child_prog *dummy)
 578 {
 579         char **e = environ;
 580         if (e == NULL) return EXIT_FAILURE;
 581         for (; *e; e++) {
 582                 puts(*e);
 583         }
 584         return EXIT_SUCCESS;
 585 }
 586
 587 /* built-in 'exec' handler */
 588 static int builtin_exec(struct child_prog *child)
 589 {
 590         if (child->argv[1] == NULL)
 591                 return EXIT_SUCCESS;   /* Really? */
 592         child->argv++;
 593         pseudo_exec(child);
 594         /* never returns */
 595 }
 596
 597 /* built-in 'exit' handler */
 598 static int builtin_exit(struct child_prog *child)
 599 {
 600         if (child->argv[1] == NULL)
 601                 exit(last_return_code);
 602         exit (atoi(child->argv[1]));
 603 }
 604
 605 /* built-in 'export VAR=value' handler */
 606 static int builtin_export(struct child_prog *child)
 607 {
 608         int res = 0;
 609         char *name = child->argv[1];
 610
 611         if (name == NULL) {
 612                 return (builtin_env(child));
 613         }
 614
 615         name = strdup(name);
 616
 617         if(name) {
 618                 char *value = strchr(name, '=');
 619
 620                 if (!value) {
 621                         char *tmp;
 622                         /* They are exporting something without an =VALUE */
 623
 624                         value = get_local_var(name);
 625                         if (value) {
 626                                 size_t ln = strlen(name);
 627
 628                                 tmp = realloc(name, ln+strlen(value)+2);
 629                                 if(tmp==NULL)
 630                                         res = -1;
 631                                 else {
 632                                         sprintf(tmp+ln, "=%s", value);
 633                                         name = tmp;
 634                                 }
 635                         } else {
 636                                 /* bash does not return an error when trying to export
 637                                  * an undefined variable.  Do likewise. */
 638                                 res = 1;
 639                         }
 640                 }
 641         }
 642         if (res<0)
 643                 perror_msg("export");
 644         else if(res==0)
 645                 res = set_local_var(name, 1);
 646         else
 647                 res = 0;
 648         free(name);
 649         return res;
 650 }
 651
 652 /* built-in 'fg' and 'bg' handler */
 653 static int builtin_fg_bg(struct child_prog *child)
 654 {
 655         int i, jobnum;
 656         struct pipe *pi=NULL;
 657
 658         if (!interactive)
 659                 return EXIT_FAILURE;
 660         /* If they gave us no args, assume they want the last backgrounded task */
 661         if (!child->argv[1]) {
 662                 for (pi = job_list; pi; pi = pi->next) {
 663                         if (pi->jobid == last_jobid) {
 664                                 break;
 665                         }
 666                 }
 667                 if (!pi) {
 668                         error_msg("%s: no current job", child->argv[0]);
 669                         return EXIT_FAILURE;
 670                 }
 671         } else {
 672                 if (sscanf(child->argv[1], "%%%d", &jobnum) != 1) {
 673                         error_msg("%s: bad argument '%s'", child->argv[0], child->argv[1]);
 674                         return EXIT_FAILURE;
 675                 }
 676                 for (pi = job_list; pi; pi = pi->next) {
 677                         if (pi->jobid == jobnum) {
 678                                 break;
 679                         }
 680                 }
 681                 if (!pi) {
 682                         error_msg("%s: %d: no such job", child->argv[0], jobnum);
 683                         return EXIT_FAILURE;
 684                 }
 685         }
 686
 687         if (*child->argv[0] == 'f') {
 688                 /* Put the job into the foreground.  */
 689                 tcsetpgrp(shell_terminal, pi->pgrp);
 690         }
 691
 692         /* Restart the processes in the job */
 693         for (i = 0; i < pi->num_progs; i++)
 694                 pi->progs[i].is_stopped = 0;
 695
 696         if ( (i=kill(- pi->pgrp, SIGCONT)) < 0) {
 697                 if (i == ESRCH) {
 698                         remove_bg_job(pi);
 699                 } else {
 700                         perror_msg("kill (SIGCONT)");
 701                 }
 702         }
 703
 704         pi->stopped_progs = 0;
 705         return EXIT_SUCCESS;
 706 }
 707
 708 /* built-in 'help' handler */
 709 static int builtin_help(struct child_prog *dummy)
 710 {
 711         struct built_in_command *x;
 712
 713         printf("\nBuilt-in commands:\n");
 714         printf("-------------------\n");
 715         for (x = bltins; x->cmd; x++) {
 716                 if (x->descr==NULL)
 717                         continue;
 718                 printf("%s\t%s\n", x->cmd, x->descr);
 719         }
 720         printf("\n\n");
 721         return EXIT_SUCCESS;
 722 }
 723
 724 /* built-in 'jobs' handler */
 725 static int builtin_jobs(struct child_prog *child)
 726 {
 727         struct pipe *job;
 728         char *status_string;
 729
 730         for (job = job_list; job; job = job->next) {
 731                 if (job->running_progs == job->stopped_progs)
 732                         status_string = "Stopped";
 733                 else
 734                         status_string = "Running";
 735
 736                 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->text);
 737         }
 738         return EXIT_SUCCESS;
 739 }
 740
 741
 742 /* built-in 'pwd' handler */
 743 static int builtin_pwd(struct child_prog *dummy)
 744 {
 745         puts(set_cwd());
 746         return EXIT_SUCCESS;
 747 }
 748
 749 /* built-in 'read VAR' handler */
 750 static int builtin_read(struct child_prog *child)
 751 {
 752         int res;
 753
 754         if (child->argv[1]) {
 755                 char string[BUFSIZ];
 756                 char *var = 0;
 757
 758                 string[0] = 0;  /* In case stdin has only EOF */
 759                 /* read string */
 760                 fgets(string, sizeof(string), stdin);
 761                 chomp(string);
 762                 var = malloc(strlen(child->argv[1])+strlen(string)+2);
 763                 if(var) {
 764                         sprintf(var, "%s=%s", child->argv[1], string);
 765                         res = set_local_var(var, 0);
 766                 } else
 767                         res = -1;
 768                 if (res)
 769                         fprintf(stderr, "read: %m\n");
 770                 free(var);      /* So not move up to avoid breaking errno */
 771                 return res;
 772         } else {
 773                 do res=getchar(); while(res!='\n' && res!=EOF);
 774                 return 0;
 775         }
 776 }
 777
 778 /* built-in 'set VAR=value' handler */
 779 static int builtin_set(struct child_prog *child)
 780 {
 781         char *temp = child->argv[1];
 782         struct variables *e;
 783
 784         if (temp == NULL)
 785                 for(e = top_vars; e; e=e->next)
 786                         printf("%s=%s\n", e->name, e->value);
 787         else
 788                 set_local_var(temp, 0);
 789
 790                 return EXIT_SUCCESS;
 791 }
 792
 793
 794 /* Built-in 'shift' handler */
 795 static int builtin_shift(struct child_prog *child)
 796 {
 797         int n=1;
 798         if (child->argv[1]) {
 799                 n=atoi(child->argv[1]);
 800         }
 801         if (n>=0 && n<global_argc) {
 802                 /* XXX This probably breaks $0 */
 803                 global_argc -= n;
 804                 global_argv += n;
 805                 return EXIT_SUCCESS;
 806         } else {
 807                 return EXIT_FAILURE;
 808         }
 809 }
 810
 811 /* Built-in '.' handler (read-in and execute commands from file) */
 812 static int builtin_source(struct child_prog *child)
 813 {
 814         FILE *input;
 815         int status;
 816
 817         if (child->argv[1] == NULL)
 818                 return EXIT_FAILURE;
 819
 820         /* XXX search through $PATH is missing */
 821         input = fopen(child->argv[1], "r");
 822         if (!input) {
 823                 error_msg("Couldn't open file '%s'", child->argv[1]);
 824                 return EXIT_FAILURE;
 825         }
 826
 827         /* Now run the file */
 828         /* XXX argv and argc are broken; need to save old global_argv
 829          * (pointer only is OK!) on this stack frame,
 830          * set global_argv=child->argv+1, recurse, and restore. */
 831         mark_open(fileno(input));
 832         status = parse_file_outer(input);
 833         mark_closed(fileno(input));
 834         fclose(input);
 835         return (status);
 836 }
 837
 838 static int builtin_umask(struct child_prog *child)
 839 {
 840         mode_t new_umask;
 841         const char *arg = child->argv[1];
 842         char *end;
 843         if (arg) {
 844                 new_umask=strtoul(arg, &end, 8);
 845                 if (*end!='\0' || end == arg) {
 846                         return EXIT_FAILURE;
 847                 }
 848         } else {
 849                 printf("%.3o\n", (unsigned int) (new_umask=umask(0)));
 850         }
 851         umask(new_umask);
 852         return EXIT_SUCCESS;
 853 }
 854
 855 /* built-in 'unset VAR' handler */
 856 static int builtin_unset(struct child_prog *child)
 857 {
 858         /* bash returned already true */
 859         unset_local_var(child->argv[1]);
 860         return EXIT_SUCCESS;
 861 }
 862
 863 static int builtin_not_written(struct child_prog *child)
 864 {
 865         printf("builtin_%s not written\n",child->argv[0]);
 866         return EXIT_FAILURE;
 867 }
 868 #endif
 869
 870 static int b_check_space(o_string *o, int len)
 871 {
 872         /* It would be easy to drop a more restrictive policy
 873          * in here, such as setting a maximum string length */
 874         if (o->length + len > o->maxlen) {
 875                 char *old_data = o->data;
 876                 /* assert (data == NULL || o->maxlen != 0); */
 877                 o->maxlen += max(2*len, B_CHUNK);
 878                 o->data = realloc(o->data, 1 + o->maxlen);
 879                 if (o->data == NULL) {
 880                         free(old_data);
 881                 }
 882         }
 883         return o->data == NULL;
 884 }
 885
 886 static int b_addchr(o_string *o, int ch)
 887 {
 888         debug_printf("b_addchr: %c %d %p\n", ch, o->length, o);
 889         if (b_check_space(o, 1)) return B_NOSPAC;
 890         o->data[o->length] = ch;
 891         o->length++;
 892         o->data[o->length] = '\0';
 893         return 0;
 894 }
 895
 896 static void b_reset(o_string *o)
 897 {
 898         o->length = 0;
 899         o->nonnull = 0;
 900         if (o->data != NULL) *o->data = '\0';
 901 }
 902
 903 static void b_free(o_string *o)
 904 {
 905         b_reset(o);
 906         free(o->data);
 907         o->data = NULL;
 908         o->maxlen = 0;
 909 }
 910
 911 /* My analysis of quoting semantics tells me that state information
 912  * is associated with a destination, not a source.
 913  */
 914 static int b_addqchr(o_string *o, int ch, int quote)
 915 {
 916         if (quote && strchr("*?[\\",ch)) {
 917                 int rc;
 918                 rc = b_addchr(o, '\\');
 919                 if (rc) return rc;
 920         }
 921         return b_addchr(o, ch);
 922 }
 923
 924 /* belongs in utility.c */
 925 char *simple_itoa(unsigned int i)
 926 {
 927         /* 21 digits plus null terminator, good for 64-bit or smaller ints */
 928         static char local[22];
 929         char *p = &local[21];
 930         *p-- = '\0';
 931         do {
 932                 *p-- = '0' + i % 10;
 933                 i /= 10;
 934         } while (i > 0);
 935         return p + 1;
 936 }
 937
 938 static int b_adduint(o_string *o, unsigned int i)
 939 {
 940         int r;
 941         char *p = simple_itoa(i);
 942         /* no escape checking necessary */
 943         do r=b_addchr(o, *p++); while (r==0 && *p);
 944         return r;
 945 }
 946
 947 static int static_get(struct in_str *i)
 948 {
 949         int ch=*i->p++;
 950         if (ch=='\0') return EOF;
 951         return ch;
 952 }
 953
 954 static int static_peek(struct in_str *i)
 955 {
 956         return *i->p;
 957 }
 958
 959 #ifndef __U_BOOT__
 960 static inline void cmdedit_set_initial_prompt(void)
 961 {
 962 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
 963         PS1 = NULL;
 964 #else
 965         PS1 = getenv("PS1");
 966         if(PS1==0)
 967                 PS1 = "\\w \\$ ";
 968 #endif
 969 }
 970
 971 static inline void setup_prompt_string(int promptmode, char **prompt_str)
 972 {
 973         debug_printf("setup_prompt_string %d ",promptmode);
 974 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
 975         /* Set up the prompt */
 976         if (promptmode == 1) {
 977                 free(PS1);
 978                 PS1=xmalloc(strlen(cwd)+4);
 979                 sprintf(PS1, "%s %s", cwd, ( geteuid() != 0 ) ?  "$ ":"# ");
 980                 *prompt_str = PS1;
 981         } else {
 982                 *prompt_str = PS2;
 983         }
 984 #else
 985         *prompt_str = (promptmode==1)? PS1 : PS2;
 986 #endif
 987         debug_printf("result %s\n",*prompt_str);
 988 }
 989 #endif
 990
 991 static void get_user_input(struct in_str *i)
 992 {
 993 #ifndef __U_BOOT__
 994         char *prompt_str;
 995         static char the_command[BUFSIZ];
 996
 997         setup_prompt_string(i->promptmode, &prompt_str);
 998 #ifdef CONFIG_FEATURE_COMMAND_EDITING
 999         /*
1000          ** enable command line editing only while a command line
1001          ** is actually being read; otherwise, we'll end up bequeathing
1002          ** atexit() handlers and other unwanted stuff to our
1003          ** child processes (rob@sysgo.de)
1004          */
1005         cmdedit_read_input(prompt_str, the_command);
1006 #else
1007         fputs(prompt_str, stdout);
1008         fflush(stdout);
1009         the_command[0]=fgetc(i->file);
1010         the_command[1]='\0';
1011 #endif
1012         fflush(stdout);
1013         i->p = the_command;
1014 #else
1015         extern char console_buffer[CFG_CBSIZE];
1016         int n;
1017         static char the_command[CFG_CBSIZE];
1018
1019         i->__promptme = 1;
1020         if (i->promptmode == 1) {
1021                 n = readline(CFG_PROMPT);
1022         } else {
1023                 n = readline(CFG_PROMPT_HUSH_PS2);
1024         }
1025         if (n == -1 ) {
1026                 flag_repeat = 0;
1027                 i->__promptme = 0;
1028         }
1029         n = strlen(console_buffer);
1030         console_buffer[n] = '\n';
1031         console_buffer[n+1]= '\0';
1032         if (had_ctrlc()) flag_repeat = 0;
1033         clear_ctrlc();
1034         do_repeat = 0;
1035         if (i->promptmode == 1) {
1036                 if (console_buffer[0] == '\n'&& flag_repeat == 0) {
1037                         strcpy(the_command,console_buffer);
1038                 }
1039                 else {
1040                         if (console_buffer[0] != '\n') {
1041                                 strcpy(the_command,console_buffer);
1042                                 flag_repeat = 1;
1043                         }
1044                         else {
1045                                 do_repeat = 1;
1046                         }
1047                 }
1048                 i->p = the_command;
1049         }
1050         else {
1051                 if (console_buffer[0] != '\n') {
1052                         if (strlen(the_command) + strlen(console_buffer)
1053                             < CFG_CBSIZE) {
1054                                 n = strlen(the_command);
1055                                 the_command[n-1] = ' ';
1056                                 strcpy(&the_command[n],console_buffer);
1057                         }
1058                         else {
1059                                 the_command[0] = '\n';
1060                                 the_command[1] = '\0';
1061                                 flag_repeat = 0;
1062                         }
1063                 }
1064                 if (i->__promptme == 0) {
1065                         the_command[0] = '\n';
1066                         the_command[1] = '\0';
1067                 }
1068                 i->p = console_buffer;
1069         }
1070 #endif
1071 }
1072
1073 /* This is the magic location that prints prompts
1074  * and gets data back from the user */
1075 static int file_get(struct in_str *i)
1076 {
1077         int ch;
1078
1079         ch = 0;
1080         /* If there is data waiting, eat it up */
1081         if (i->p && *i->p) {
1082                 ch=*i->p++;
1083         } else {
1084                 /* need to double check i->file because we might be doing something
1085                  * more complicated by now, like sourcing or substituting. */
1086 #ifndef __U_BOOT__
1087                 if (i->__promptme && interactive && i->file == stdin) {
1088                         while(! i->p || (interactive && strlen(i->p)==0) ) {
1089 #else
1090                         while(! i->p  || strlen(i->p)==0 ) {
1091 #endif
1092                                 get_user_input(i);
1093                         }
1094                         i->promptmode=2;
1095 #ifndef __U_BOOT__
1096                         i->__promptme = 0;
1097 #endif
1098                         if (i->p && *i->p) {
1099                                 ch=*i->p++;
1100                         }
1101 #ifndef __U_BOOT__
1102                 } else {
1103                         ch = fgetc(i->file);
1104                 }
1105
1106 #endif
1107                 debug_printf("b_getch: got a %d\n", ch);
1108         }
1109 #ifndef __U_BOOT__
1110         if (ch == '\n') i->__promptme=1;
1111 #endif
1112         return ch;
1113 }
1114
1115 /* All the callers guarantee this routine will never be
1116  * used right after a newline, so prompting is not needed.
1117  */
1118 static int file_peek(struct in_str *i)
1119 {
1120 #ifndef __U_BOOT__
1121         if (i->p && *i->p) {
1122 #endif
1123                 return *i->p;
1124 #ifndef __U_BOOT__
1125         } else {
1126                 i->peek_buf[0] = fgetc(i->file);
1127                 i->peek_buf[1] = '\0';
1128                 i->p = i->peek_buf;
1129                 debug_printf("b_peek: got a %d\n", *i->p);
1130                 return *i->p;
1131         }
1132 #endif
1133 }
1134
1135 #ifndef __U_BOOT__
1136 static void setup_file_in_str(struct in_str *i, FILE *f)
1137 #else
1138 static void setup_file_in_str(struct in_str *i)
1139 #endif
1140 {
1141         i->peek = file_peek;
1142         i->get = file_get;
1143         i->__promptme=1;
1144         i->promptmode=1;
1145 #ifndef __U_BOOT__
1146         i->file = f;
1147 #endif
1148         i->p = NULL;
1149 }
1150
1151 static void setup_string_in_str(struct in_str *i, const char *s)
1152 {
1153         i->peek = static_peek;
1154         i->get = static_get;
1155         i->__promptme=1;
1156         i->promptmode=1;
1157         i->p = s;
1158 }
1159
1160 #ifndef __U_BOOT__
1161 static void mark_open(int fd)
1162 {
1163         struct close_me *new = xmalloc(sizeof(struct close_me));
1164         new->fd = fd;
1165         new->next = close_me_head;
1166         close_me_head = new;
1167 }
1168
1169 static void mark_closed(int fd)
1170 {
1171         struct close_me *tmp;
1172         if (close_me_head == NULL || close_me_head->fd != fd)
1173                 error_msg_and_die("corrupt close_me");
1174         tmp = close_me_head;
1175         close_me_head = close_me_head->next;
1176         free(tmp);
1177 }
1178
1179 static void close_all(void)
1180 {
1181         struct close_me *c;
1182         for (c=close_me_head; c; c=c->next) {
1183                 close(c->fd);
1184         }
1185         close_me_head = NULL;
1186 }
1187
1188 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
1189  * and stderr if they are redirected. */
1190 static int setup_redirects(struct child_prog *prog, int squirrel[])
1191 {
1192         int openfd, mode;
1193         struct redir_struct *redir;
1194
1195         for (redir=prog->redirects; redir; redir=redir->next) {
1196                 if (redir->dup == -1 && redir->word.gl_pathv == NULL) {
1197                         /* something went wrong in the parse.  Pretend it didn't happen */
1198                         continue;
1199                 }
1200                 if (redir->dup == -1) {
1201                         mode=redir_table[redir->type].mode;
1202                         openfd = open(redir->word.gl_pathv[0], mode, 0666);
1203                         if (openfd < 0) {
1204                         /* this could get lost if stderr has been redirected, but
1205                            bash and ash both lose it as well (though zsh doesn't!) */
1206                                 perror_msg("error opening %s", redir->word.gl_pathv[0]);
1207                                 return 1;
1208                         }
1209                 } else {
1210                         openfd = redir->dup;
1211                 }
1212
1213                 if (openfd != redir->fd) {
1214                         if (squirrel && redir->fd < 3) {
1215                                 squirrel[redir->fd] = dup(redir->fd);
1216                         }
1217                         if (openfd == -3) {
1218                                 close(openfd);
1219                         } else {
1220                                 dup2(openfd, redir->fd);
1221                                 if (redir->dup == -1)
1222                                         close (openfd);
1223                         }
1224                 }
1225         }
1226         return 0;
1227 }
1228
1229 static void restore_redirects(int squirrel[])
1230 {
1231         int i, fd;
1232         for (i=0; i<3; i++) {
1233                 fd = squirrel[i];
1234                 if (fd != -1) {
1235                         /* No error checking.  I sure wouldn't know what
1236                          * to do with an error if I found one! */
1237                         dup2(fd, i);
1238                         close(fd);
1239                 }
1240         }
1241 }
1242
1243 /* never returns */
1244 /* XXX no exit() here.  If you don't exec, use _exit instead.
1245  * The at_exit handlers apparently confuse the calling process,
1246  * in particular stdin handling.  Not sure why? */
1247 static void pseudo_exec(struct child_prog *child)
1248 {
1249         int i, rcode;
1250         char *p;
1251         struct built_in_command *x;
1252         if (child->argv) {
1253                 for (i=0; is_assignment(child->argv[i]); i++) {
1254                         debug_printf("pid %d environment modification: %s\n",getpid(),child->argv[i]);
1255                         p = insert_var_value(child->argv[i]);
1256                         putenv(strdup(p));
1257                         if (p != child->argv[i]) free(p);
1258                 }
1259                 child->argv+=i;  /* XXX this hack isn't so horrible, since we are about
1260                                         to exit, and therefore don't need to keep data
1261                                         structures consistent for free() use. */
1262                 /* If a variable is assigned in a forest, and nobody listens,
1263                  * was it ever really set?
1264                  */
1265                 if (child->argv[0] == NULL) {
1266                         _exit(EXIT_SUCCESS);
1267                 }
1268
1269                 /*
1270                  * Check if the command matches any of the builtins.
1271                  * Depending on context, this might be redundant.  But it's
1272                  * easier to waste a few CPU cycles than it is to figure out
1273                  * if this is one of those cases.
1274                  */
1275                 for (x = bltins; x->cmd; x++) {
1276                         if (strcmp(child->argv[0], x->cmd) == 0 ) {
1277                                 debug_printf("builtin exec %s\n", child->argv[0]);
1278                                 rcode = x->function(child);
1279                                 fflush(stdout);
1280                                 _exit(rcode);
1281                         }
1282                 }
1283
1284                 /* Check if the command matches any busybox internal commands
1285                  * ("applets") here.
1286                  * FIXME: This feature is not 100% safe, since
1287                  * BusyBox is not fully reentrant, so we have no guarantee the things
1288                  * from the .bss are still zeroed, or that things from .data are still
1289                  * at their defaults.  We could exec ourself from /proc/self/exe, but I
1290                  * really dislike relying on /proc for things.  We could exec ourself
1291                  * from global_argv[0], but if we are in a chroot, we may not be able
1292                  * to find ourself... */
1293 #ifdef CONFIG_FEATURE_SH_STANDALONE_SHELL
1294                 {
1295                         int argc_l;
1296                         char** argv_l=child->argv;
1297                         char *name = child->argv[0];
1298
1299 #ifdef CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN
1300                         /* Following discussions from November 2000 on the busybox mailing
1301                          * list, the default configuration, (without
1302                          * get_last_path_component()) lets the user force use of an
1303                          * external command by specifying the full (with slashes) filename.
1304                          * If you enable CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN then applets
1305                          * _aways_ override external commands, so if you want to run
1306                          * /bin/cat, it will use BusyBox cat even if /bin/cat exists on the
1307                          * filesystem and is _not_ busybox.  Some systems may want this,
1308                          * most do not.  */
1309                         name = get_last_path_component(name);
1310 #endif
1311                         /* Count argc for use in a second... */
1312                         for(argc_l=0;*argv_l!=NULL; argv_l++, argc_l++);
1313                         optind = 1;
1314                         debug_printf("running applet %s\n", name);
1315                         run_applet_by_name(name, argc_l, child->argv);
1316                 }
1317 #endif
1318                 debug_printf("exec of %s\n",child->argv[0]);
1319                 execvp(child->argv[0],child->argv);
1320                 perror_msg("couldn't exec: %s",child->argv[0]);
1321                 _exit(1);
1322         } else if (child->group) {
1323                 debug_printf("runtime nesting to group\n");
1324                 interactive=0;    /* crucial!!!! */
1325                 rcode = run_list_real(child->group);
1326                 /* OK to leak memory by not calling free_pipe_list,
1327                  * since this process is about to exit */
1328                 _exit(rcode);
1329         } else {
1330                 /* Can happen.  See what bash does with ">foo" by itself. */
1331                 debug_printf("trying to pseudo_exec null command\n");
1332                 _exit(EXIT_SUCCESS);
1333         }
1334 }
1335
1336 static void insert_bg_job(struct pipe *pi)
1337 {
1338         struct pipe *thejob;
1339
1340         /* Linear search for the ID of the job to use */
1341         pi->jobid = 1;
1342         for (thejob = job_list; thejob; thejob = thejob->next)
1343                 if (thejob->jobid >= pi->jobid)
1344                         pi->jobid = thejob->jobid + 1;
1345
1346         /* add thejob to the list of running jobs */
1347         if (!job_list) {
1348                 thejob = job_list = xmalloc(sizeof(*thejob));
1349         } else {
1350                 for (thejob = job_list; thejob->next; thejob = thejob->next) /* nothing */;
1351                 thejob->next = xmalloc(sizeof(*thejob));
1352                 thejob = thejob->next;
1353         }
1354
1355         /* physically copy the struct job */
1356         memcpy(thejob, pi, sizeof(struct pipe));
1357         thejob->next = NULL;
1358         thejob->running_progs = thejob->num_progs;
1359         thejob->stopped_progs = 0;
1360         thejob->text = xmalloc(BUFSIZ); /* cmdedit buffer size */
1361
1362         /*if (pi->progs[0] && pi->progs[0].argv && pi->progs[0].argv[0]) */
1363         {
1364                 char *bar=thejob->text;
1365                 char **foo=pi->progs[0].argv;
1366                 while(foo && *foo) {
1367                         bar += sprintf(bar, "%s ", *foo++);
1368                 }
1369         }
1370
1371         /* we don't wait for background thejobs to return -- append it
1372            to the list of backgrounded thejobs and leave it alone */
1373         printf("[%d] %d\n", thejob->jobid, thejob->progs[0].pid);
1374         last_bg_pid = thejob->progs[0].pid;
1375         last_jobid = thejob->jobid;
1376 }
1377
1378 /* remove a backgrounded job */
1379 static void remove_bg_job(struct pipe *pi)
1380 {
1381         struct pipe *prev_pipe;
1382
1383         if (pi == job_list) {
1384                 job_list = pi->next;
1385         } else {
1386                 prev_pipe = job_list;
1387                 while (prev_pipe->next != pi)
1388                         prev_pipe = prev_pipe->next;
1389                 prev_pipe->next = pi->next;
1390         }
1391         if (job_list)
1392                 last_jobid = job_list->jobid;
1393         else
1394                 last_jobid = 0;
1395
1396         pi->stopped_progs = 0;
1397         free_pipe(pi, 0);
1398         free(pi);
1399 }
1400
1401 /* Checks to see if any processes have exited -- if they
1402    have, figure out why and see if a job has completed */
1403 static int checkjobs(struct pipe* fg_pipe)
1404 {
1405         int attributes;
1406         int status;
1407         int prognum = 0;
1408         struct pipe *pi;
1409         pid_t childpid;
1410
1411         attributes = WUNTRACED;
1412         if (fg_pipe==NULL) {
1413                 attributes |= WNOHANG;
1414         }
1415
1416         while ((childpid = waitpid(-1, &status, attributes)) > 0) {
1417                 if (fg_pipe) {
1418                         int i, rcode = 0;
1419                         for (i=0; i < fg_pipe->num_progs; i++) {
1420                                 if (fg_pipe->progs[i].pid == childpid) {
1421                                         if (i==fg_pipe->num_progs-1)
1422                                                 rcode=WEXITSTATUS(status);
1423                                         (fg_pipe->num_progs)--;
1424                                         return(rcode);
1425                                 }
1426                         }
1427                 }
1428
1429                 for (pi = job_list; pi; pi = pi->next) {
1430                         prognum = 0;
1431                         while (prognum < pi->num_progs && pi->progs[prognum].pid != childpid) {
1432                                 prognum++;
1433                         }
1434                         if (prognum < pi->num_progs)
1435                                 break;
1436                 }
1437
1438                 if(pi==NULL) {
1439                         debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
1440                         continue;
1441                 }
1442
1443                 if (WIFEXITED(status) || WIFSIGNALED(status)) {
1444                         /* child exited */
1445                         pi->running_progs--;
1446                         pi->progs[prognum].pid = 0;
1447
1448                         if (!pi->running_progs) {
1449                                 printf(JOB_STATUS_FORMAT, pi->jobid, "Done", pi->text);
1450                                 remove_bg_job(pi);
1451                         }
1452                 } else {
1453                         /* child stopped */
1454                         pi->stopped_progs++;
1455                         pi->progs[prognum].is_stopped = 1;
1456
1457 #if 0
1458                         /* Printing this stuff is a pain, since it tends to
1459                          * overwrite the prompt an inconveinient moments.  So
1460                          * don't do that.  */
1461                         if (pi->stopped_progs == pi->num_progs) {
1462                                 printf("\n"JOB_STATUS_FORMAT, pi->jobid, "Stopped", pi->text);
1463                         }
1464 #endif
1465                 }
1466         }
1467
1468         if (childpid == -1 && errno != ECHILD)
1469                 perror_msg("waitpid");
1470
1471         /* move the shell to the foreground */
1472         /*if (interactive && tcsetpgrp(shell_terminal, getpgid(0))) */
1473         /*      perror_msg("tcsetpgrp-2"); */
1474         return -1;
1475 }
1476
1477 /* Figure out our controlling tty, checking in order stderr,
1478  * stdin, and stdout.  If check_pgrp is set, also check that
1479  * we belong to the foreground process group associated with
1480  * that tty.  The value of shell_terminal is needed in order to call
1481  * tcsetpgrp(shell_terminal, ...); */
1482 void controlling_tty(int check_pgrp)
1483 {
1484         pid_t curpgrp;
1485
1486         if ((curpgrp = tcgetpgrp(shell_terminal = 2)) < 0
1487                         && (curpgrp = tcgetpgrp(shell_terminal = 0)) < 0
1488                         && (curpgrp = tcgetpgrp(shell_terminal = 1)) < 0)
1489                 goto shell_terminal_error;
1490
1491         if (check_pgrp && curpgrp != getpgid(0))
1492                 goto shell_terminal_error;
1493
1494         return;
1495
1496 shell_terminal_error:
1497                 shell_terminal = -1;
1498                 return;
1499 }
1500 #endif
1501
1502 /* run_pipe_real() starts all the jobs, but doesn't wait for anything
1503  * to finish.  See checkjobs().
1504  *
1505  * return code is normally -1, when the caller has to wait for children
1506  * to finish to determine the exit status of the pipe.  If the pipe
1507  * is a simple builtin command, however, the action is done by the
1508  * time run_pipe_real returns, and the exit code is provided as the
1509  * return value.
1510  *
1511  * The input of the pipe is always stdin, the output is always
1512  * stdout.  The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
1513  * because it tries to avoid running the command substitution in
1514  * subshell, when that is in fact necessary.  The subshell process
1515  * now has its stdout directed to the input of the appropriate pipe,
1516  * so this routine is noticeably simpler.
1517  */
1518 static int run_pipe_real(struct pipe *pi)
1519 {
1520         int i;
1521 #ifndef __U_BOOT__
1522         int nextin, nextout;
1523         int pipefds[2];                         /* pipefds[0] is for reading */
1524         struct child_prog *child;
1525         struct built_in_command *x;
1526         char *p;
1527 # if __GNUC__
1528         /* Avoid longjmp clobbering */
1529         (void) &i;
1530         (void) &nextin;
1531         (void) &nextout;
1532         (void) &child;
1533 # endif
1534 #else
1535         int nextin;
1536         int flag = do_repeat ? CMD_FLAG_REPEAT : 0;
1537         struct child_prog *child;
1538         cmd_tbl_t *cmdtp;
1539         char *p;
1540 # if __GNUC__
1541         /* Avoid longjmp clobbering */
1542         (void) &i;
1543         (void) &nextin;
1544         (void) &child;
1545 # endif
1546 #endif  /* __U_BOOT__ */
1547
1548         nextin = 0;
1549 #ifndef __U_BOOT__
1550         pi->pgrp = -1;
1551 #endif
1552
1553         /* Check if this is a simple builtin (not part of a pipe).
1554          * Builtins within pipes have to fork anyway, and are handled in
1555          * pseudo_exec.  "echo foo | read bar" doesn't work on bash, either.
1556          */
1557         if (pi->num_progs == 1) child = & (pi->progs[0]);
1558 #ifndef __U_BOOT__
1559         if (pi->num_progs == 1 && child->group && child->subshell == 0) {
1560                 int squirrel[] = {-1, -1, -1};
1561                 int rcode;
1562                 debug_printf("non-subshell grouping\n");
1563                 setup_redirects(child, squirrel);
1564                 /* XXX could we merge code with following builtin case,
1565                  * by creating a pseudo builtin that calls run_list_real? */
1566                 rcode = run_list_real(child->group);
1567                 restore_redirects(squirrel);
1568 #else
1569                 if (pi->num_progs == 1 && child->group) {
1570                 int rcode;
1571                 debug_printf("non-subshell grouping\n");
1572                 rcode = run_list_real(child->group);
1573 #endif
1574                 return rcode;
1575         } else if (pi->num_progs == 1 && pi->progs[0].argv != NULL) {
1576                 for (i=0; is_assignment(child->argv[i]); i++) { /* nothing */ }
1577                 if (i!=0 && child->argv[i]==NULL) {
1578                         /* assignments, but no command: set the local environment */
1579                         for (i=0; child->argv[i]!=NULL; i++) {
1580
1581                                 /* Ok, this case is tricky.  We have to decide if this is a
1582                                  * local variable, or an already exported variable.  If it is
1583                                  * already exported, we have to export the new value.  If it is
1584                                  * not exported, we need only set this as a local variable.
1585                                  * This junk is all to decide whether or not to export this
1586                                  * variable. */
1587                                 int export_me=0;
1588                                 char *name, *value;
1589                                 name = xstrdup(child->argv[i]);
1590                                 debug_printf("Local environment set: %s\n", name);
1591                                 value = strchr(name, '=');
1592                                 if (value)
1593                                         *value=0;
1594 #ifndef __U_BOOT__
1595                                 if ( get_local_var(name)) {
1596                                         export_me=1;
1597                                 }
1598 #endif
1599                                 free(name);
1600                                 p = insert_var_value(child->argv[i]);
1601                                 set_local_var(p, export_me);
1602                                 if (p != child->argv[i]) free(p);
1603                         }
1604                         return EXIT_SUCCESS;   /* don't worry about errors in set_local_var() yet */
1605                 }
1606                 for (i = 0; is_assignment(child->argv[i]); i++) {
1607                         p = insert_var_value(child->argv[i]);
1608 #ifndef __U_BOOT__
1609                         putenv(strdup(p));
1610 #else
1611                         set_local_var(p, 0);
1612 #endif
1613                         if (p != child->argv[i]) {
1614                                 child->sp--;
1615                                 free(p);
1616                         }
1617                 }
1618                 if (child->sp) {
1619                         char * str = NULL;
1620
1621                         str = make_string((child->argv + i));
1622                         parse_string_outer(str, FLAG_EXIT_FROM_LOOP | FLAG_REPARSING);
1623                         free(str);
1624                         return last_return_code;
1625                 }
1626 #ifndef __U_BOOT__
1627                 for (x = bltins; x->cmd; x++) {
1628                         if (strcmp(child->argv[i], x->cmd) == 0 ) {
1629                                 int squirrel[] = {-1, -1, -1};
1630                                 int rcode;
1631                                 if (x->function == builtin_exec && child->argv[i+1]==NULL) {
1632                                         debug_printf("magic exec\n");
1633                                         setup_redirects(child,NULL);
1634                                         return EXIT_SUCCESS;
1635                                 }
1636                                 debug_printf("builtin inline %s\n", child->argv[0]);
1637                                 /* XXX setup_redirects acts on file descriptors, not FILEs.
1638                                  * This is perfect for work that comes after exec().
1639                                  * Is it really safe for inline use?  Experimentally,
1640                                  * things seem to work with glibc. */
1641                                 setup_redirects(child, squirrel);
1642 #else
1643                         /* check ";", because ,example , argv consist from
1644                          * "help;flinfo" must not execute
1645                          */
1646                         if (strchr(child->argv[i], ';')) {
1647                                 printf ("Unknown command '%s' - try 'help' or use 'run' command\n",
1648                                         child->argv[i]);
1649                                 return -1;
1650                         }
1651                         /* Look up command in command table */
1652                         if ((cmdtp = find_cmd(child->argv[i])) == NULL) {
1653                                 printf ("Unknown command '%s' - try 'help'\n", child->argv[i]);
1654                                 return -1;      /* give up after bad command */
1655                         } else {
1656                                 int rcode;
1657 #if (CONFIG_COMMANDS & CFG_CMD_BOOTD)
1658                                 /* avoid "bootd" recursion */
1659                                 if (cmdtp->cmd == do_bootd) {
1660                                         if (flag & CMD_FLAG_BOOTD) {
1661                                                 printf ("'bootd' recursion detected\n");
1662                                                 return -1;
1663                                         }
1664                                 else
1665                                         flag |= CMD_FLAG_BOOTD;
1666                                 }
1667 #endif  /* CFG_CMD_BOOTD */
1668                                 /* found - check max args */
1669                                 if ((child->argc - i) > cmdtp->maxargs) {
1670                                         printf ("Usage:\n%s\n", cmdtp->usage);
1671                                         return -1;
1672                                 }
1673 #endif
1674                                 child->argv+=i;  /* XXX horrible hack */
1675 #ifndef __U_BOOT__
1676                                 rcode = x->function(child);
1677 #else
1678                                 /* OK - call function to do the command */
1679                                 rcode = (cmdtp->cmd)
1680                                         (cmdtp, flag,child->argc-i,&child->argv[i]);
1681                                 if ( !cmdtp->repeatable )
1682                                         flag_repeat = 0;
1683 #endif
1684                                 child->argv-=i;  /* XXX restore hack so free() can work right */
1685 #ifndef __U_BOOT__
1686                                 restore_redirects(squirrel);
1687 #endif
1688                                 return rcode;
1689                         }
1690                 }
1691 #ifndef __U_BOOT__
1692         }
1693
1694         for (i = 0; i < pi->num_progs; i++) {
1695                 child = & (pi->progs[i]);
1696
1697                 /* pipes are inserted between pairs of commands */
1698                 if ((i + 1) < pi->num_progs) {
1699                         if (pipe(pipefds)<0) perror_msg_and_die("pipe");
1700                         nextout = pipefds[1];
1701                 } else {
1702                         nextout=1;
1703                         pipefds[0] = -1;
1704                 }
1705
1706                 /* XXX test for failed fork()? */
1707                 if (!(child->pid = fork())) {
1708                         /* Set the handling for job control signals back to the default.  */
1709                         signal(SIGINT, SIG_DFL);
1710                         signal(SIGQUIT, SIG_DFL);
1711                         signal(SIGTERM, SIG_DFL);
1712                         signal(SIGTSTP, SIG_DFL);
1713                         signal(SIGTTIN, SIG_DFL);
1714                         signal(SIGTTOU, SIG_DFL);
1715                         signal(SIGCHLD, SIG_DFL);
1716
1717                         close_all();
1718
1719                         if (nextin != 0) {
1720                                 dup2(nextin, 0);
1721                                 close(nextin);
1722                         }
1723                         if (nextout != 1) {
1724                                 dup2(nextout, 1);
1725                                 close(nextout);
1726                         }
1727                         if (pipefds[0]!=-1) {
1728                                 close(pipefds[0]);  /* opposite end of our output pipe */
1729                         }
1730
1731                         /* Like bash, explicit redirects override pipes,
1732                          * and the pipe fd is available for dup'ing. */
1733                         setup_redirects(child,NULL);
1734
1735                         if (interactive && pi->followup!=PIPE_BG) {
1736                                 /* If we (the child) win the race, put ourselves in the process
1737                                  * group whose leader is the first process in this pipe. */
1738                                 if (pi->pgrp < 0) {
1739                                         pi->pgrp = getpid();
1740                                 }
1741                                 if (setpgid(0, pi->pgrp) == 0) {
1742                                         tcsetpgrp(2, pi->pgrp);
1743                                 }
1744                         }
1745
1746                         pseudo_exec(child);
1747                 }
1748
1749
1750                 /* put our child in the process group whose leader is the
1751                    first process in this pipe */
1752                 if (pi->pgrp < 0) {
1753                         pi->pgrp = child->pid;
1754                 }
1755                 /* Don't check for errors.  The child may be dead already,
1756                  * in which case setpgid returns error code EACCES. */
1757                 setpgid(child->pid, pi->pgrp);
1758
1759                 if (nextin != 0)
1760                         close(nextin);
1761                 if (nextout != 1)
1762                         close(nextout);
1763
1764                 /* If there isn't another process, nextin is garbage
1765                    but it doesn't matter */
1766                 nextin = pipefds[0];
1767         }
1768 #endif
1769         return -1;
1770 }
1771
1772 static int run_list_real(struct pipe *pi)
1773 {
1774         char *save_name = NULL;
1775         char **list = NULL;
1776         char **save_list = NULL;
1777         struct pipe *rpipe;
1778         int flag_rep = 0;
1779 #ifndef __U_BOOT__
1780         int save_num_progs;
1781 #endif
1782         int rcode=0, flag_skip=1;
1783         int flag_restore = 0;
1784         int if_code=0, next_if_code=0;  /* need double-buffer to handle elif */
1785         reserved_style rmode, skip_more_in_this_rmode=RES_XXXX;
1786         /* check syntax for "for" */
1787         for (rpipe = pi; rpipe; rpipe = rpipe->next) {
1788                 if ((rpipe->r_mode == RES_IN ||
1789                     rpipe->r_mode == RES_FOR) &&
1790                     (rpipe->next == NULL)) {
1791                                 syntax();
1792 #ifdef __U_BOOT__
1793                                 flag_repeat = 0;
1794 #endif
1795                                 return 1;
1796                 }
1797                 if ((rpipe->r_mode == RES_IN &&
1798                         (rpipe->next->r_mode == RES_IN &&
1799                         rpipe->next->progs->argv != NULL))||
1800                         (rpipe->r_mode == RES_FOR &&
1801                         rpipe->next->r_mode != RES_IN)) {
1802                                 syntax();
1803 #ifdef __U_BOOT__
1804                                 flag_repeat = 0;
1805 #endif
1806                                 return 1;
1807                 }
1808         }
1809         for (; pi; pi = (flag_restore != 0) ? rpipe : pi->next) {
1810                 if (pi->r_mode == RES_WHILE || pi->r_mode == RES_UNTIL ||
1811                         pi->r_mode == RES_FOR) {
1812 #ifdef __U_BOOT__
1813                                 /* check Ctrl-C */
1814                                 ctrlc();
1815                                 if ((had_ctrlc())) {
1816                                         return 1;
1817                                 }
1818 #endif
1819                                 flag_restore = 0;
1820                                 if (!rpipe) {
1821                                         flag_rep = 0;
1822                                         rpipe = pi;
1823                                 }
1824                 }
1825                 rmode = pi->r_mode;
1826                 debug_printf("rmode=%d  if_code=%d  next_if_code=%d skip_more=%d\n", rmode, if_code, next_if_code, skip_more_in_this_rmode);
1827                 if (rmode == skip_more_in_this_rmode && flag_skip) {
1828                         if (pi->followup == PIPE_SEQ) flag_skip=0;
1829                         continue;
1830                 }
1831                 flag_skip = 1;
1832                 skip_more_in_this_rmode = RES_XXXX;
1833                 if (rmode == RES_THEN || rmode == RES_ELSE) if_code = next_if_code;
1834                 if (rmode == RES_THEN &&  if_code) continue;
1835                 if (rmode == RES_ELSE && !if_code) continue;
1836                 if (rmode == RES_ELIF && !if_code) continue;
1837                 if (rmode == RES_FOR && pi->num_progs) {
1838                         if (!list) {
1839                                 /* if no variable values after "in" we skip "for" */
1840                                 if (!pi->next->progs->argv) continue;
1841                                 /* create list of variable values */
1842                                 list = make_list_in(pi->next->progs->argv,
1843                                         pi->progs->argv[0]);
1844                                 save_list = list;
1845                                 save_name = pi->progs->argv[0];
1846                                 pi->progs->argv[0] = NULL;
1847                                 flag_rep = 1;
1848                         }
1849                         if (!(*list)) {
1850                                 free(pi->progs->argv[0]);
1851                                 free(save_list);
1852                                 list = NULL;
1853                                 flag_rep = 0;
1854                                 pi->progs->argv[0] = save_name;
1855 #ifndef __U_BOOT__
1856                                 pi->progs->glob_result.gl_pathv[0] =
1857                                         pi->progs->argv[0];
1858 #endif
1859                                 continue;
1860                         } else {
1861                                 /* insert new value from list for variable */
1862                                 if (pi->progs->argv[0])
1863                                         free(pi->progs->argv[0]);
1864                                 pi->progs->argv[0] = *list++;
1865 #ifndef __U_BOOT__
1866                                 pi->progs->glob_result.gl_pathv[0] =
1867                                         pi->progs->argv[0];
1868 #endif
1869                         }
1870                 }
1871                 if (rmode == RES_IN) continue;
1872                 if (rmode == RES_DO) {
1873                         if (!flag_rep) continue;
1874                 }
1875                 if ((rmode == RES_DONE)) {
1876                         if (flag_rep) {
1877                                 flag_restore = 1;
1878                         } else {
1879                                 rpipe = NULL;
1880                         }
1881                 }
1882                 if (pi->num_progs == 0) continue;
1883 #ifndef __U_BOOT__
1884                 save_num_progs = pi->num_progs; /* save number of programs */
1885 #endif
1886                 rcode = run_pipe_real(pi);
1887                 debug_printf("run_pipe_real returned %d\n",rcode);
1888 #ifndef __U_BOOT__
1889                 if (rcode!=-1) {
1890                         /* We only ran a builtin: rcode was set by the return value
1891                          * of run_pipe_real(), and we don't need to wait for anything. */
1892                 } else if (pi->followup==PIPE_BG) {
1893                         /* XXX check bash's behavior with nontrivial pipes */
1894                         /* XXX compute jobid */
1895                         /* XXX what does bash do with attempts to background builtins? */
1896                         insert_bg_job(pi);
1897                         rcode = EXIT_SUCCESS;
1898                 } else {
1899                         if (interactive) {
1900                                 /* move the new process group into the foreground */
1901                                 if (tcsetpgrp(shell_terminal, pi->pgrp) && errno != ENOTTY)
1902                                         perror_msg("tcsetpgrp-3");
1903                                 rcode = checkjobs(pi);
1904                                 /* move the shell to the foreground */
1905                                 if (tcsetpgrp(shell_terminal, getpgid(0)) && errno != ENOTTY)
1906                                         perror_msg("tcsetpgrp-4");
1907                         } else {
1908                                 rcode = checkjobs(pi);
1909                         }
1910                         debug_printf("checkjobs returned %d\n",rcode);
1911                 }
1912                 last_return_code=rcode;
1913 #else
1914                 last_return_code=(rcode == 0) ? 0 : 1;
1915 #endif
1916 #ifndef __U_BOOT__
1917                 pi->num_progs = save_num_progs; /* restore number of programs */
1918 #endif
1919                 if ( rmode == RES_IF || rmode == RES_ELIF )
1920                         next_if_code=rcode;  /* can be overwritten a number of times */
1921                 if (rmode == RES_WHILE)
1922                         flag_rep = !last_return_code;
1923                 if (rmode == RES_UNTIL)
1924                         flag_rep = last_return_code;
1925                 if ( (rcode==EXIT_SUCCESS && pi->followup==PIPE_OR) ||
1926                      (rcode!=EXIT_SUCCESS && pi->followup==PIPE_AND) )
1927                         skip_more_in_this_rmode=rmode;
1928 #ifndef __U_BOOT__
1929                 checkjobs(NULL);
1930 #endif
1931         }
1932         return rcode;
1933 }
1934
1935 /* broken, of course, but OK for testing */
1936 static char *indenter(int i)
1937 {
1938         static char blanks[]="                                    ";
1939         return &blanks[sizeof(blanks)-i-1];
1940 }
1941
1942 /* return code is the exit status of the pipe */
1943 static int free_pipe(struct pipe *pi, int indent)
1944 {
1945         char **p;
1946         struct child_prog *child;
1947 #ifndef __U_BOOT__
1948         struct redir_struct *r, *rnext;
1949 #endif
1950         int a, i, ret_code=0;
1951         char *ind = indenter(indent);
1952
1953 #ifndef __U_BOOT__
1954         if (pi->stopped_progs > 0)
1955                 return ret_code;
1956         final_printf("%s run pipe: (pid %d)\n",ind,getpid());
1957 #endif
1958         for (i=0; i<pi->num_progs; i++) {
1959                 child = &pi->progs[i];
1960                 final_printf("%s  command %d:\n",ind,i);
1961                 if (child->argv) {
1962                         for (a=0,p=child->argv; *p; a++,p++) {
1963                                 final_printf("%s   argv[%d] = %s\n",ind,a,*p);
1964                         }
1965 #ifndef __U_BOOT__
1966                         globfree(&child->glob_result);
1967 #else
1968                         for (a = child->argc;a >= 0;a--) {
1969                                 free(child->argv[a]);
1970                         }
1971                                         free(child->argv);
1972                         child->argc = 0;
1973 #endif
1974                         child->argv=NULL;
1975                 } else if (child->group) {
1976 #ifndef __U_BOOT__
1977                         final_printf("%s   begin group (subshell:%d)\n",ind, child->subshell);
1978 #endif
1979                         ret_code = free_pipe_list(child->group,indent+3);
1980                         final_printf("%s   end group\n",ind);
1981                 } else {
1982                         final_printf("%s   (nil)\n",ind);
1983                 }
1984 #ifndef __U_BOOT__
1985                 for (r=child->redirects; r; r=rnext) {
1986                         final_printf("%s   redirect %d%s", ind, r->fd, redir_table[r->type].descrip);
1987                         if (r->dup == -1) {
1988                                 /* guard against the case >$FOO, where foo is unset or blank */
1989                                 if (r->word.gl_pathv) {
1990                                         final_printf(" %s\n", *r->word.gl_pathv);
1991                                         globfree(&r->word);
1992                                 }
1993                         } else {
1994                                 final_printf("&%d\n", r->dup);
1995                         }
1996                         rnext=r->next;
1997                         free(r);
1998                 }
1999                 child->redirects=NULL;
2000 #endif
2001         }
2002         free(pi->progs);   /* children are an array, they get freed all at once */
2003         pi->progs=NULL;
2004         return ret_code;
2005 }
2006
2007 static int free_pipe_list(struct pipe *head, int indent)
2008 {
2009         int rcode=0;   /* if list has no members */
2010         struct pipe *pi, *next;
2011         char *ind = indenter(indent);
2012         for (pi=head; pi; pi=next) {
2013                 final_printf("%s pipe reserved mode %d\n", ind, pi->r_mode);
2014                 rcode = free_pipe(pi, indent);
2015                 final_printf("%s pipe followup code %d\n", ind, pi->followup);
2016                 next=pi->next;
2017                 pi->next=NULL;
2018                 free(pi);
2019         }
2020         return rcode;
2021 }
2022
2023 /* Select which version we will use */
2024 static int run_list(struct pipe *pi)
2025 {
2026         int rcode=0;
2027 #ifndef __U_BOOT__
2028         if (fake_mode==0) {
2029 #endif
2030                 rcode = run_list_real(pi);
2031 #ifndef __U_BOOT__
2032         }
2033 #endif
2034         /* free_pipe_list has the side effect of clearing memory
2035          * In the long run that function can be merged with run_list_real,
2036          * but doing that now would hobble the debugging effort. */
2037         free_pipe_list(pi,0);
2038         return rcode;
2039 }
2040
2041 /* The API for glob is arguably broken.  This routine pushes a non-matching
2042  * string into the output structure, removing non-backslashed backslashes.
2043  * If someone can prove me wrong, by performing this function within the
2044  * original glob(3) api, feel free to rewrite this routine into oblivion.
2045  * Return code (0 vs. GLOB_NOSPACE) matches glob(3).
2046  * XXX broken if the last character is '\\', check that before calling.
2047  */
2048 #ifndef __U_BOOT__
2049 static int globhack(const char *src, int flags, glob_t *pglob)
2050 {
2051         int cnt=0, pathc;
2052         const char *s;
2053         char *dest;
2054         for (cnt=1, s=src; s && *s; s++) {
2055                 if (*s == '\\') s++;
2056                 cnt++;
2057         }
2058         dest = malloc(cnt);
2059         if (!dest) return GLOB_NOSPACE;
2060         if (!(flags & GLOB_APPEND)) {
2061                 pglob->gl_pathv=NULL;
2062                 pglob->gl_pathc=0;
2063                 pglob->gl_offs=0;
2064                 pglob->gl_offs=0;
2065         }
2066         pathc = ++pglob->gl_pathc;
2067         pglob->gl_pathv = realloc(pglob->gl_pathv, (pathc+1)*sizeof(*pglob->gl_pathv));
2068         if (pglob->gl_pathv == NULL) return GLOB_NOSPACE;
2069         pglob->gl_pathv[pathc-1]=dest;
2070         pglob->gl_pathv[pathc]=NULL;
2071         for (s=src; s && *s; s++, dest++) {
2072                 if (*s == '\\') s++;
2073                 *dest = *s;
2074         }
2075         *dest='\0';
2076         return 0;
2077 }
2078
2079 /* XXX broken if the last character is '\\', check that before calling */
2080 static int glob_needed(const char *s)
2081 {
2082         for (; *s; s++) {
2083                 if (*s == '\\') s++;
2084                 if (strchr("*[?",*s)) return 1;
2085         }
2086         return 0;
2087 }
2088
2089 #if 0
2090 static void globprint(glob_t *pglob)
2091 {
2092         int i;
2093         debug_printf("glob_t at %p:\n", pglob);
2094         debug_printf("  gl_pathc=%d  gl_pathv=%p  gl_offs=%d  gl_flags=%d\n",
2095                 pglob->gl_pathc, pglob->gl_pathv, pglob->gl_offs, pglob->gl_flags);
2096         for (i=0; i<pglob->gl_pathc; i++)
2097                 debug_printf("pglob->gl_pathv[%d] = %p = %s\n", i,
2098                         pglob->gl_pathv[i], pglob->gl_pathv[i]);
2099 }
2100 #endif
2101
2102 static int xglob(o_string *dest, int flags, glob_t *pglob)
2103 {
2104         int gr;
2105
2106         /* short-circuit for null word */
2107         /* we can code this better when the debug_printf's are gone */
2108         if (dest->length == 0) {
2109                 if (dest->nonnull) {
2110                         /* bash man page calls this an "explicit" null */
2111                         gr = globhack(dest->data, flags, pglob);
2112                         debug_printf("globhack returned %d\n",gr);
2113                 } else {
2114                         return 0;
2115                 }
2116         } else if (glob_needed(dest->data)) {
2117                 gr = glob(dest->data, flags, NULL, pglob);
2118                 debug_printf("glob returned %d\n",gr);
2119                 if (gr == GLOB_NOMATCH) {
2120                         /* quote removal, or more accurately, backslash removal */
2121                         gr = globhack(dest->data, flags, pglob);
2122                         debug_printf("globhack returned %d\n",gr);
2123                 }
2124         } else {
2125                 gr = globhack(dest->data, flags, pglob);
2126                 debug_printf("globhack returned %d\n",gr);
2127         }
2128         if (gr == GLOB_NOSPACE)
2129                 error_msg_and_die("out of memory during glob");
2130         if (gr != 0) { /* GLOB_ABORTED ? */
2131                 error_msg("glob(3) error %d",gr);
2132         }
2133         /* globprint(glob_target); */
2134         return gr;
2135 }
2136 #endif
2137
2138 /* This is used to get/check local shell variables */
2139 static char *get_local_var(const char *s)
2140 {
2141         struct variables *cur;
2142
2143         if (!s)
2144                 return NULL;
2145         for (cur = top_vars; cur; cur=cur->next)
2146                 if(strcmp(cur->name, s)==0)
2147                         return cur->value;
2148         return NULL;
2149 }
2150
2151 /* This is used to set local shell variables
2152    flg_export==0 if only local (not exporting) variable
2153    flg_export==1 if "new" exporting environ
2154    flg_export>1  if current startup environ (not call putenv()) */
2155 static int set_local_var(const char *s, int flg_export)
2156 {
2157         char *name, *value;
2158         int result=0;
2159         struct variables *cur;
2160
2161         name=strdup(s);
2162
2163 #ifdef __U_BOOT__
2164         if (getenv(name) != NULL) {
2165                 printf ("ERROR: "
2166                                 "There is a global environmet variable with the same name.\n");
2167                 return -1;
2168         }
2169 #endif
2170         /* Assume when we enter this function that we are already in
2171          * NAME=VALUE format.  So the first order of business is to
2172          * split 's' on the '=' into 'name' and 'value' */
2173         value = strchr(name, '=');
2174         if (value==0 && ++value==0) {
2175                 free(name);
2176                 return -1;
2177         }
2178         *value++ = 0;
2179
2180         for(cur = top_vars; cur; cur = cur->next) {
2181                 if(strcmp(cur->name, name)==0)
2182                         break;
2183         }
2184
2185         if(cur) {
2186                 if(strcmp(cur->value, value)==0) {
2187                         if(flg_export>0 && cur->flg_export==0)
2188                                 cur->flg_export=flg_export;
2189                         else
2190                                 result++;
2191                 } else {
2192                         if(cur->flg_read_only) {
2193                                 error_msg("%s: readonly variable", name);
2194                                 result = -1;
2195                         } else {
2196                                 if(flg_export>0 || cur->flg_export>1)
2197                                         cur->flg_export=1;
2198                                 free(cur->value);
2199
2200                                 cur->value = strdup(value);
2201                         }
2202                 }
2203         } else {
2204                 cur = malloc(sizeof(struct variables));
2205                 if(!cur) {
2206                         result = -1;
2207                 } else {
2208                         cur->name = strdup(name);
2209                         if(cur->name == 0) {
2210                                 free(cur);
2211                                 result = -1;
2212                         } else {
2213                                 struct variables *bottom = top_vars;
2214                                 cur->value = strdup(value);
2215                                 cur->next = 0;
2216                                 cur->flg_export = flg_export;
2217                                 cur->flg_read_only = 0;
2218                                 while(bottom->next) bottom=bottom->next;
2219                                 bottom->next = cur;
2220                         }
2221                 }
2222         }
2223
2224 #ifndef __U_BOOT__
2225         if(result==0 && cur->flg_export==1) {
2226                 *(value-1) = '=';
2227                 result = putenv(name);
2228         } else {
2229 #endif
2230                 free(name);
2231 #ifndef __U_BOOT__
2232                 if(result>0)            /* equivalent to previous set */
2233                         result = 0;
2234         }
2235 #endif
2236         return result;
2237 }
2238
2239 #ifndef __U_BOOT__
2240 static void unset_local_var(const char *name)
2241 {
2242         struct variables *cur;
2243
2244         if (name) {
2245                 for (cur = top_vars; cur; cur=cur->next) {
2246                         if(strcmp(cur->name, name)==0)
2247                                 break;
2248                 }
2249                 if(cur!=0) {
2250                         struct variables *next = top_vars;
2251                         if(cur->flg_read_only) {
2252                                 error_msg("%s: readonly variable", name);
2253                                 return;
2254                         } else {
2255                                 if(cur->flg_export)
2256                                         unsetenv(cur->name);
2257                                 free(cur->name);
2258                                 free(cur->value);
2259                                 while (next->next != cur)
2260                                         next = next->next;
2261                                 next->next = cur->next;
2262                         }
2263                         free(cur);
2264                 }
2265         }
2266 }
2267 #endif
2268
2269 static int is_assignment(const char *s)
2270 {
2271         if (s==NULL || !isalpha(*s)) return 0;
2272         ++s;
2273         while(isalnum(*s) || *s=='_') ++s;
2274         return *s=='=';
2275 }
2276
2277 #ifndef __U_BOOT__
2278 /* the src parameter allows us to peek forward to a possible &n syntax
2279  * for file descriptor duplication, e.g., "2>&1".
2280  * Return code is 0 normally, 1 if a syntax error is detected in src.
2281  * Resource errors (in xmalloc) cause the process to exit */
2282 static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
2283         struct in_str *input)
2284 {
2285         struct child_prog *child=ctx->child;
2286         struct redir_struct *redir = child->redirects;
2287         struct redir_struct *last_redir=NULL;
2288
2289         /* Create a new redir_struct and drop it onto the end of the linked list */
2290         while(redir) {
2291                 last_redir=redir;
2292                 redir=redir->next;
2293         }
2294         redir = xmalloc(sizeof(struct redir_struct));
2295         redir->next=NULL;
2296         redir->word.gl_pathv=NULL;
2297         if (last_redir) {
2298                 last_redir->next=redir;
2299         } else {
2300                 child->redirects=redir;
2301         }
2302
2303         redir->type=style;
2304         redir->fd= (fd==-1) ? redir_table[style].default_fd : fd ;
2305
2306         debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
2307
2308         /* Check for a '2>&1' type redirect */
2309         redir->dup = redirect_dup_num(input);
2310         if (redir->dup == -2) return 1;  /* syntax error */
2311         if (redir->dup != -1) {
2312                 /* Erik had a check here that the file descriptor in question
2313                  * is legit; I postpone that to "run time"
2314                  * A "-" representation of "close me" shows up as a -3 here */
2315                 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
2316         } else {
2317                 /* We do _not_ try to open the file that src points to,
2318                  * since we need to return and let src be expanded first.
2319                  * Set ctx->pending_redirect, so we know what to do at the
2320                  * end of the next parsed word.
2321                  */
2322                 ctx->pending_redirect = redir;
2323         }
2324         return 0;
2325 }
2326 #endif
2327
2328 struct pipe *new_pipe(void) {
2329         struct pipe *pi;
2330         pi = xmalloc(sizeof(struct pipe));
2331         pi->num_progs = 0;
2332         pi->progs = NULL;
2333         pi->next = NULL;
2334         pi->followup = 0;  /* invalid */
2335         return pi;
2336 }
2337
2338 static void initialize_context(struct p_context *ctx)
2339 {
2340         ctx->pipe=NULL;
2341 #ifndef __U_BOOT__
2342         ctx->pending_redirect=NULL;
2343 #endif
2344         ctx->child=NULL;
2345         ctx->list_head=new_pipe();
2346         ctx->pipe=ctx->list_head;
2347         ctx->w=RES_NONE;
2348         ctx->stack=NULL;
2349 #ifdef __U_BOOT__
2350         ctx->old_flag=0;
2351 #endif
2352         done_command(ctx);   /* creates the memory for working child */
2353 }
2354
2355 /* normal return is 0
2356  * if a reserved word is found, and processed, return 1
2357  * should handle if, then, elif, else, fi, for, while, until, do, done.
2358  * case, function, and select are obnoxious, save those for later.
2359  */
2360 int reserved_word(o_string *dest, struct p_context *ctx)
2361 {
2362         struct reserved_combo {
2363                 char *literal;
2364                 int code;
2365                 long flag;
2366         };
2367         /* Mostly a list of accepted follow-up reserved words.
2368          * FLAG_END means we are done with the sequence, and are ready
2369          * to turn the compound list into a command.
2370          * FLAG_START means the word must start a new compound list.
2371          */
2372         static struct reserved_combo reserved_list[] = {
2373                 { "if",    RES_IF,    FLAG_THEN | FLAG_START },
2374                 { "then",  RES_THEN,  FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2375                 { "elif",  RES_ELIF,  FLAG_THEN },
2376                 { "else",  RES_ELSE,  FLAG_FI   },
2377                 { "fi",    RES_FI,    FLAG_END  },
2378                 { "for",   RES_FOR,   FLAG_IN   | FLAG_START },
2379                 { "while", RES_WHILE, FLAG_DO   | FLAG_START },
2380                 { "until", RES_UNTIL, FLAG_DO   | FLAG_START },
2381                 { "in",    RES_IN,    FLAG_DO   },
2382                 { "do",    RES_DO,    FLAG_DONE },
2383                 { "done",  RES_DONE,  FLAG_END  }
2384         };
2385         struct reserved_combo *r;
2386         for (r=reserved_list;
2387 #define NRES sizeof(reserved_list)/sizeof(struct reserved_combo)
2388                 r<reserved_list+NRES; r++) {
2389                 if (strcmp(dest->data, r->literal) == 0) {
2390                         debug_printf("found reserved word %s, code %d\n",r->literal,r->code);
2391                         if (r->flag & FLAG_START) {
2392                                 struct p_context *new = xmalloc(sizeof(struct p_context));
2393                                 debug_printf("push stack\n");
2394                                 if (ctx->w == RES_IN || ctx->w == RES_FOR) {
2395                                         syntax();
2396                                         free(new);
2397                                         ctx->w = RES_SNTX;
2398                                         b_reset(dest);
2399                                         return 1;
2400                                 }
2401                                 *new = *ctx;   /* physical copy */
2402                                 initialize_context(ctx);
2403                                 ctx->stack=new;
2404                         } else if ( ctx->w == RES_NONE || ! (ctx->old_flag & (1<<r->code))) {
2405                                 syntax();
2406                                 ctx->w = RES_SNTX;
2407                                 b_reset(dest);
2408                                 return 1;
2409                         }
2410                         ctx->w=r->code;
2411                         ctx->old_flag = r->flag;
2412                         if (ctx->old_flag & FLAG_END) {
2413                                 struct p_context *old;
2414                                 debug_printf("pop stack\n");
2415                                 done_pipe(ctx,PIPE_SEQ);
2416                                 old = ctx->stack;
2417                                 old->child->group = ctx->list_head;
2418 #ifndef __U_BOOT__
2419                                 old->child->subshell = 0;
2420 #endif
2421                                 *ctx = *old;   /* physical copy */
2422                                 free(old);
2423                         }
2424                         b_reset (dest);
2425                         return 1;
2426                 }
2427         }
2428         return 0;
2429 }
2430
2431 /* normal return is 0.
2432  * Syntax or xglob errors return 1. */
2433 static int done_word(o_string *dest, struct p_context *ctx)
2434 {
2435         struct child_prog *child=ctx->child;
2436 #ifndef __U_BOOT__
2437         glob_t *glob_target;
2438         int gr, flags = 0;
2439 #else
2440         char *str, *s;
2441         int argc, cnt;
2442 #endif
2443
2444         debug_printf("done_word: %s %p\n", dest->data, child);
2445         if (dest->length == 0 && !dest->nonnull) {
2446                 debug_printf("  true null, ignored\n");
2447                 return 0;
2448         }
2449 #ifndef __U_BOOT__
2450         if (ctx->pending_redirect) {
2451                 glob_target = &ctx->pending_redirect->word;
2452         } else {
2453 #endif
2454                 if (child->group) {
2455                         syntax();
2456                         return 1;  /* syntax error, groups and arglists don't mix */
2457                 }
2458                 if (!child->argv && (ctx->type & FLAG_PARSE_SEMICOLON)) {
2459                         debug_printf("checking %s for reserved-ness\n",dest->data);
2460                         if (reserved_word(dest,ctx)) return ctx->w==RES_SNTX;
2461                 }
2462 #ifndef __U_BOOT__
2463                 glob_target = &child->glob_result;
2464                 if (child->argv) flags |= GLOB_APPEND;
2465 #else
2466                 for (cnt = 1, s = dest->data; s && *s; s++) {
2467                         if (*s == '\\') s++;
2468                         cnt++;
2469                 }
2470                 str = malloc(cnt);
2471                 if (!str) return 1;
2472                 if ( child->argv == NULL) {
2473                         child->argc=0;
2474                 }
2475                 argc = ++child->argc;
2476                 child->argv = realloc(child->argv, (argc+1)*sizeof(*child->argv));
2477                 if (child->argv == NULL) return 1;
2478                 child->argv[argc-1]=str;
2479                 child->argv[argc]=NULL;
2480                 for (s = dest->data; s && *s; s++,str++) {
2481                         if (*s == '\\') s++;
2482                         *str = *s;
2483                 }
2484                 *str = '\0';
2485 #endif
2486 #ifndef __U_BOOT__
2487         }
2488         gr = xglob(dest, flags, glob_target);
2489         if (gr != 0) return 1;
2490 #endif
2491
2492         b_reset(dest);
2493 #ifndef __U_BOOT__
2494         if (ctx->pending_redirect) {
2495                 ctx->pending_redirect=NULL;
2496                 if (glob_target->gl_pathc != 1) {
2497                         error_msg("ambiguous redirect");
2498                         return 1;
2499                 }
2500         } else {
2501                 child->argv = glob_target->gl_pathv;
2502         }
2503 #endif
2504         if (ctx->w == RES_FOR) {
2505                 done_word(dest,ctx);
2506                 done_pipe(ctx,PIPE_SEQ);
2507         }
2508         return 0;
2509 }
2510
2511 /* The only possible error here is out of memory, in which case
2512  * xmalloc exits. */
2513 static int done_command(struct p_context *ctx)
2514 {
2515         /* The child is really already in the pipe structure, so
2516          * advance the pipe counter and make a new, null child.
2517          * Only real trickiness here is that the uncommitted
2518          * child structure, to which ctx->child points, is not
2519          * counted in pi->num_progs. */
2520         struct pipe *pi=ctx->pipe;
2521         struct child_prog *prog=ctx->child;
2522
2523         if (prog && prog->group == NULL
2524                  && prog->argv == NULL
2525 #ifndef __U_BOOT__
2526                  && prog->redirects == NULL) {
2527 #else
2528                                                                                 ) {
2529 #endif
2530                 debug_printf("done_command: skipping null command\n");
2531                 return 0;
2532         } else if (prog) {
2533                 pi->num_progs++;
2534                 debug_printf("done_command: num_progs incremented to %d\n",pi->num_progs);
2535         } else {
2536                 debug_printf("done_command: initializing\n");
2537         }
2538         pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
2539
2540         prog = pi->progs + pi->num_progs;
2541 #ifndef __U_BOOT__
2542         prog->redirects = NULL;
2543 #endif
2544         prog->argv = NULL;
2545 #ifndef __U_BOOT__
2546         prog->is_stopped = 0;
2547 #endif
2548         prog->group = NULL;
2549 #ifndef __U_BOOT__
2550         prog->glob_result.gl_pathv = NULL;
2551         prog->family = pi;
2552 #endif
2553         prog->sp = 0;
2554         ctx->child = prog;
2555         prog->type = ctx->type;
2556
2557         /* but ctx->pipe and ctx->list_head remain unchanged */
2558         return 0;
2559 }
2560
2561 static int done_pipe(struct p_context *ctx, pipe_style type)
2562 {
2563         struct pipe *new_p;
2564         done_command(ctx);  /* implicit closure of previous command */
2565         debug_printf("done_pipe, type %d\n", type);
2566         ctx->pipe->followup = type;
2567         ctx->pipe->r_mode = ctx->w;
2568         new_p=new_pipe();
2569         ctx->pipe->next = new_p;
2570         ctx->pipe = new_p;
2571         ctx->child = NULL;
2572         done_command(ctx);  /* set up new pipe to accept commands */
2573         return 0;
2574 }
2575
2576 #ifndef __U_BOOT__
2577 /* peek ahead in the in_str to find out if we have a "&n" construct,
2578  * as in "2>&1", that represents duplicating a file descriptor.
2579  * returns either -2 (syntax error), -1 (no &), or the number found.
2580  */
2581 static int redirect_dup_num(struct in_str *input)
2582 {
2583         int ch, d=0, ok=0;
2584         ch = b_peek(input);
2585         if (ch != '&') return -1;
2586
2587         b_getch(input);  /* get the & */
2588         ch=b_peek(input);
2589         if (ch == '-') {
2590                 b_getch(input);
2591                 return -3;  /* "-" represents "close me" */
2592         }
2593         while (isdigit(ch)) {
2594                 d = d*10+(ch-'0');
2595                 ok=1;
2596                 b_getch(input);
2597                 ch = b_peek(input);
2598         }
2599         if (ok) return d;
2600
2601         error_msg("ambiguous redirect");
2602         return -2;
2603 }
2604
2605 /* If a redirect is immediately preceded by a number, that number is
2606  * supposed to tell which file descriptor to redirect.  This routine
2607  * looks for such preceding numbers.  In an ideal world this routine
2608  * needs to handle all the following classes of redirects...
2609  *     echo 2>foo     # redirects fd  2 to file "foo", nothing passed to echo
2610  *     echo 49>foo    # redirects fd 49 to file "foo", nothing passed to echo
2611  *     echo -2>foo    # redirects fd  1 to file "foo",    "-2" passed to echo
2612  *     echo 49x>foo   # redirects fd  1 to file "foo",   "49x" passed to echo
2613  * A -1 output from this program means no valid number was found, so the
2614  * caller should use the appropriate default for this redirection.
2615  */
2616 static int redirect_opt_num(o_string *o)
2617 {
2618         int num;
2619
2620         if (o->length==0) return -1;
2621         for(num=0; num<o->length; num++) {
2622                 if (!isdigit(*(o->data+num))) {
2623                         return -1;
2624                 }
2625         }
2626         /* reuse num (and save an int) */
2627         num=atoi(o->data);
2628         b_reset(o);
2629         return num;
2630 }
2631
2632 FILE *generate_stream_from_list(struct pipe *head)
2633 {
2634         FILE *pf;
2635 #if 1
2636         int pid, channel[2];
2637         if (pipe(channel)<0) perror_msg_and_die("pipe");
2638         pid=fork();
2639         if (pid<0) {
2640                 perror_msg_and_die("fork");
2641         } else if (pid==0) {
2642                 close(channel[0]);
2643                 if (channel[1] != 1) {
2644                         dup2(channel[1],1);
2645                         close(channel[1]);
2646                 }
2647 #if 0
2648 #define SURROGATE "surrogate response"
2649                 write(1,SURROGATE,sizeof(SURROGATE));
2650                 _exit(run_list(head));
2651 #else
2652                 _exit(run_list_real(head));   /* leaks memory */
2653 #endif
2654         }
2655         debug_printf("forked child %d\n",pid);
2656         close(channel[1]);
2657         pf = fdopen(channel[0],"r");
2658         debug_printf("pipe on FILE *%p\n",pf);
2659 #else
2660         free_pipe_list(head,0);
2661         pf=popen("echo surrogate response","r");
2662         debug_printf("started fake pipe on FILE *%p\n",pf);
2663 #endif
2664         return pf;
2665 }
2666
2667 /* this version hacked for testing purposes */
2668 /* return code is exit status of the process that is run. */
2669 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end)
2670 {
2671         int retcode;
2672         o_string result=NULL_O_STRING;
2673         struct p_context inner;
2674         FILE *p;
2675         struct in_str pipe_str;
2676         initialize_context(&inner);
2677
2678         /* recursion to generate command */
2679         retcode = parse_stream(&result, &inner, input, subst_end);
2680         if (retcode != 0) return retcode;  /* syntax error or EOF */
2681         done_word(&result, &inner);
2682         done_pipe(&inner, PIPE_SEQ);
2683         b_free(&result);
2684
2685         p=generate_stream_from_list(inner.list_head);
2686         if (p==NULL) return 1;
2687         mark_open(fileno(p));
2688         setup_file_in_str(&pipe_str, p);
2689
2690         /* now send results of command back into original context */
2691         retcode = parse_stream(dest, ctx, &pipe_str, '\0');
2692         /* XXX In case of a syntax error, should we try to kill the child?
2693          * That would be tough to do right, so just read until EOF. */
2694         if (retcode == 1) {
2695                 while (b_getch(&pipe_str)!=EOF) { /* discard */ };
2696         }
2697
2698         debug_printf("done reading from pipe, pclose()ing\n");
2699         /* This is the step that wait()s for the child.  Should be pretty
2700          * safe, since we just read an EOF from its stdout.  We could try
2701          * to better, by using wait(), and keeping track of background jobs
2702          * at the same time.  That would be a lot of work, and contrary
2703          * to the KISS philosophy of this program. */
2704         mark_closed(fileno(p));
2705         retcode=pclose(p);
2706         free_pipe_list(inner.list_head,0);
2707         debug_printf("pclosed, retcode=%d\n",retcode);
2708         /* XXX this process fails to trim a single trailing newline */
2709         return retcode;
2710 }
2711
2712 static int parse_group(o_string *dest, struct p_context *ctx,
2713         struct in_str *input, int ch)
2714 {
2715         int rcode, endch=0;
2716         struct p_context sub;
2717         struct child_prog *child = ctx->child;
2718         if (child->argv) {
2719                 syntax();
2720                 return 1;  /* syntax error, groups and arglists don't mix */
2721         }
2722         initialize_context(&sub);
2723         switch(ch) {
2724                 case '(': endch=')'; child->subshell=1; break;
2725                 case '{': endch='}'; break;
2726                 default: syntax();   /* really logic error */
2727         }
2728         rcode=parse_stream(dest,&sub,input,endch);
2729         done_word(dest,&sub); /* finish off the final word in the subcontext */
2730         done_pipe(&sub, PIPE_SEQ);  /* and the final command there, too */
2731         child->group = sub.list_head;
2732         return rcode;
2733         /* child remains "open", available for possible redirects */
2734 }
2735 #endif
2736
2737 /* basically useful version until someone wants to get fancier,
2738  * see the bash man page under "Parameter Expansion" */
2739 static char *lookup_param(char *src)
2740 {
2741         char *p=NULL;
2742         if (src) {
2743                 p = getenv(src);
2744                 if (!p)
2745                         p = get_local_var(src);
2746         }
2747         return p;
2748 }
2749
2750 /* return code: 0 for OK, 1 for syntax error */
2751 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input)
2752 {
2753 #ifndef __U_BOOT__
2754         int i, advance=0;
2755 #else
2756         int advance=0;
2757 #endif
2758 #ifndef __U_BOOT__
2759         char sep[]=" ";
2760 #endif
2761         int ch = input->peek(input);  /* first character after the $ */
2762         debug_printf("handle_dollar: ch=%c\n",ch);
2763         if (isalpha(ch)) {
2764                 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2765                 ctx->child->sp++;
2766                 while(ch=b_peek(input),isalnum(ch) || ch=='_') {
2767                         b_getch(input);
2768                         b_addchr(dest,ch);
2769                 }
2770                 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2771 #ifndef __U_BOOT__
2772         } else if (isdigit(ch)) {
2773                 i = ch-'0';  /* XXX is $0 special? */
2774                 if (i<global_argc) {
2775                         parse_string(dest, ctx, global_argv[i]); /* recursion */
2776                 }
2777                 advance = 1;
2778 #endif
2779         } else switch (ch) {
2780 #ifndef __U_BOOT__
2781                 case '$':
2782                         b_adduint(dest,getpid());
2783                         advance = 1;
2784                         break;
2785                 case '!':
2786                         if (last_bg_pid > 0) b_adduint(dest, last_bg_pid);
2787                         advance = 1;
2788                         break;
2789 #endif
2790                 case '?':
2791                         b_adduint(dest,last_return_code);
2792                         advance = 1;
2793                         break;
2794 #ifndef __U_BOOT__
2795                 case '#':
2796                         b_adduint(dest,global_argc ? global_argc-1 : 0);
2797                         advance = 1;
2798                         break;
2799 #endif
2800                 case '{':
2801                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2802                         ctx->child->sp++;
2803                         b_getch(input);
2804                         /* XXX maybe someone will try to escape the '}' */
2805                         while(ch=b_getch(input),ch!=EOF && ch!='}') {
2806                                 b_addchr(dest,ch);
2807                         }
2808                         if (ch != '}') {
2809                                 syntax();
2810                                 return 1;
2811                         }
2812                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2813                         break;
2814 #ifndef __U_BOOT__
2815                 case '(':
2816                         b_getch(input);
2817                         process_command_subs(dest, ctx, input, ')');
2818                         break;
2819                 case '*':
2820                         sep[0]=ifs[0];
2821                         for (i=1; i<global_argc; i++) {
2822                                 parse_string(dest, ctx, global_argv[i]);
2823                                 if (i+1 < global_argc) parse_string(dest, ctx, sep);
2824                         }
2825                         break;
2826                 case '@':
2827                 case '-':
2828                 case '_':
2829                         /* still unhandled, but should be eventually */
2830                         error_msg("unhandled syntax: $%c",ch);
2831                         return 1;
2832                         break;
2833 #endif
2834                 default:
2835                         b_addqchr(dest,'$',dest->quote);
2836         }
2837         /* Eat the character if the flag was set.  If the compiler
2838          * is smart enough, we could substitute "b_getch(input);"
2839          * for all the "advance = 1;" above, and also end up with
2840          * a nice size-optimized program.  Hah!  That'll be the day.
2841          */
2842         if (advance) b_getch(input);
2843         return 0;
2844 }
2845
2846 #ifndef __U_BOOT__
2847 int parse_string(o_string *dest, struct p_context *ctx, const char *src)
2848 {
2849         struct in_str foo;
2850         setup_string_in_str(&foo, src);
2851         return parse_stream(dest, ctx, &foo, '\0');
2852 }
2853 #endif
2854
2855 /* return code is 0 for normal exit, 1 for syntax error */
2856 int parse_stream(o_string *dest, struct p_context *ctx,
2857         struct in_str *input, int end_trigger)
2858 {
2859         unsigned int ch, m;
2860 #ifndef __U_BOOT__
2861         int redir_fd;
2862         redir_type redir_style;
2863 #endif
2864         int next;
2865
2866         /* Only double-quote state is handled in the state variable dest->quote.
2867          * A single-quote triggers a bypass of the main loop until its mate is
2868          * found.  When recursing, quote state is passed in via dest->quote. */
2869
2870         debug_printf("parse_stream, end_trigger=%d\n",end_trigger);
2871         while ((ch=b_getch(input))!=EOF) {
2872                 m = map[ch];
2873 #ifdef __U_BOOT__
2874                 if (input->__promptme == 0) return 1;
2875 #endif
2876                 next = (ch == '\n') ? 0 : b_peek(input);
2877                 debug_printf("parse_stream: ch=%c (%d) m=%d quote=%d\n",
2878                         ch,ch,m,dest->quote);
2879                 if (m==0 || ((m==1 || m==2) && dest->quote)) {
2880                         b_addqchr(dest, ch, dest->quote);
2881                 } else {
2882                         if (m==2) {  /* unquoted IFS */
2883                                 if (done_word(dest, ctx)) {
2884                                         return 1;
2885                                 }
2886                                 /* If we aren't performing a substitution, treat a newline as a
2887                                  * command separator.  */
2888                                 if (end_trigger != '\0' && ch=='\n')
2889                                         done_pipe(ctx,PIPE_SEQ);
2890                         }
2891                         if (ch == end_trigger && !dest->quote && ctx->w==RES_NONE) {
2892                                 debug_printf("leaving parse_stream (triggered)\n");
2893                                 return 0;
2894                         }
2895 #if 0
2896                         if (ch=='\n') {
2897                                 /* Yahoo!  Time to run with it! */
2898                                 done_pipe(ctx,PIPE_SEQ);
2899                                 run_list(ctx->list_head);
2900                                 initialize_context(ctx);
2901                         }
2902 #endif
2903                         if (m!=2) switch (ch) {
2904                 case '#':
2905                         if (dest->length == 0 && !dest->quote) {
2906                                 while(ch=b_peek(input),ch!=EOF && ch!='\n') { b_getch(input); }
2907                         } else {
2908                                 b_addqchr(dest, ch, dest->quote);
2909                         }
2910                         break;
2911                 case '\\':
2912                         if (next == EOF) {
2913                                 syntax();
2914                                 return 1;
2915                         }
2916                         b_addqchr(dest, '\\', dest->quote);
2917                         b_addqchr(dest, b_getch(input), dest->quote);
2918                         break;
2919                 case '$':
2920                         if (handle_dollar(dest, ctx, input)!=0) return 1;
2921                         break;
2922                 case '\'':
2923                         dest->nonnull = 1;
2924                         while(ch=b_getch(input),ch!=EOF && ch!='\'') {
2925 #ifdef __U_BOOT__
2926                                 if(input->__promptme == 0) return 1;
2927 #endif
2928                                 b_addchr(dest,ch);
2929                         }
2930                         if (ch==EOF) {
2931                                 syntax();
2932                                 return 1;
2933                         }
2934                         break;
2935                 case '"':
2936                         dest->nonnull = 1;
2937                         dest->quote = !dest->quote;
2938                         break;
2939 #ifndef __U_BOOT__
2940                 case '`':
2941                         process_command_subs(dest, ctx, input, '`');
2942                         break;
2943                 case '>':
2944                         redir_fd = redirect_opt_num(dest);
2945                         done_word(dest, ctx);
2946                         redir_style=REDIRECT_OVERWRITE;
2947                         if (next == '>') {
2948                                 redir_style=REDIRECT_APPEND;
2949                                 b_getch(input);
2950                         } else if (next == '(') {
2951                                 syntax();   /* until we support >(list) Process Substitution */
2952                                 return 1;
2953                         }
2954                         setup_redirect(ctx, redir_fd, redir_style, input);
2955                         break;
2956                 case '<':
2957                         redir_fd = redirect_opt_num(dest);
2958                         done_word(dest, ctx);
2959                         redir_style=REDIRECT_INPUT;
2960                         if (next == '<') {
2961                                 redir_style=REDIRECT_HEREIS;
2962                                 b_getch(input);
2963                         } else if (next == '>') {
2964                                 redir_style=REDIRECT_IO;
2965                                 b_getch(input);
2966                         } else if (next == '(') {
2967                                 syntax();   /* until we support <(list) Process Substitution */
2968                                 return 1;
2969                         }
2970                         setup_redirect(ctx, redir_fd, redir_style, input);
2971                         break;
2972 #endif
2973                 case ';':
2974                         done_word(dest, ctx);
2975                         done_pipe(ctx,PIPE_SEQ);
2976                         break;
2977                 case '&':
2978                         done_word(dest, ctx);
2979                         if (next=='&') {
2980                                 b_getch(input);
2981                                 done_pipe(ctx,PIPE_AND);
2982                         } else {
2983 #ifndef __U_BOOT__
2984                                 done_pipe(ctx,PIPE_BG);
2985 #else
2986                                 syntax_err();
2987                                 return 1;
2988 #endif
2989                         }
2990                         break;
2991                 case '|':
2992                         done_word(dest, ctx);
2993                         if (next=='|') {
2994                                 b_getch(input);
2995                                 done_pipe(ctx,PIPE_OR);
2996                         } else {
2997                                 /* we could pick up a file descriptor choice here
2998                                  * with redirect_opt_num(), but bash doesn't do it.
2999                                  * "echo foo 2| cat" yields "foo 2". */
3000 #ifndef __U_BOOT__
3001                                 done_command(ctx);
3002 #else
3003                                 syntax_err();
3004                                 return 1;
3005 #endif
3006                         }
3007                         break;
3008 #ifndef __U_BOOT__
3009                 case '(':
3010                 case '{':
3011                         if (parse_group(dest, ctx, input, ch)!=0) return 1;
3012                         break;
3013                 case ')':
3014                 case '}':
3015                         syntax();   /* Proper use of this character caught by end_trigger */
3016                         return 1;
3017                         break;
3018 #endif
3019                 default:
3020                         syntax();   /* this is really an internal logic error */
3021                         return 1;
3022                         }
3023                 }
3024         }
3025         /* complain if quote?  No, maybe we just finished a command substitution
3026          * that was quoted.  Example:
3027          * $ echo "`cat foo` plus more"
3028          * and we just got the EOF generated by the subshell that ran "cat foo"
3029          * The only real complaint is if we got an EOF when end_trigger != '\0',
3030          * that is, we were really supposed to get end_trigger, and never got
3031          * one before the EOF.  Can't use the standard "syntax error" return code,
3032          * so that parse_stream_outer can distinguish the EOF and exit smoothly. */
3033         debug_printf("leaving parse_stream (EOF)\n");
3034         if (end_trigger != '\0') return -1;
3035         return 0;
3036 }
3037
3038 void mapset(const unsigned char *set, int code)
3039 {
3040         const unsigned char *s;
3041         for (s=set; *s; s++) map[*s] = code;
3042 }
3043
3044 void update_ifs_map(void)
3045 {
3046         /* char *ifs and char map[256] are both globals. */
3047         ifs = getenv("IFS");
3048         if (ifs == NULL) ifs=" \t\n";
3049         /* Precompute a list of 'flow through' behavior so it can be treated
3050          * quickly up front.  Computation is necessary because of IFS.
3051          * Special case handling of IFS == " \t\n" is not implemented.
3052          * The map[] array only really needs two bits each, and on most machines
3053          * that would be faster because of the reduced L1 cache footprint.
3054          */
3055         memset(map,0,sizeof(map)); /* most characters flow through always */
3056 #ifndef __U_BOOT__
3057         mapset("\\$'\"`", 3);      /* never flow through */
3058         mapset("<>;&|(){}#", 1);   /* flow through if quoted */
3059 #else
3060         mapset("\\$'\"", 3);       /* never flow through */
3061         mapset(";&|#", 1);         /* flow through if quoted */
3062 #endif
3063         mapset(ifs, 2);            /* also flow through if quoted */
3064 }
3065
3066 /* most recursion does not come through here, the exeception is
3067  * from builtin_source() */
3068 int parse_stream_outer(struct in_str *inp, int flag)
3069 {
3070
3071         struct p_context ctx;
3072         o_string temp=NULL_O_STRING;
3073         int rcode;
3074 #ifdef __U_BOOT__
3075         int code = 0;
3076 #endif
3077         do {
3078                 ctx.type = flag;
3079                 initialize_context(&ctx);
3080                 update_ifs_map();
3081                 if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING)) mapset(";$&|", 0);
3082                 inp->promptmode=1;
3083                 rcode = parse_stream(&temp, &ctx, inp, '\n');
3084 #ifdef __U_BOOT__
3085                 if (rcode == 1) flag_repeat = 0;
3086 #endif
3087                 if (rcode != 1 && ctx.old_flag != 0) {
3088                         syntax();
3089 #ifdef __U_BOOT__
3090                         flag_repeat = 0;
3091 #endif
3092                 }
3093                 if (rcode != 1 && ctx.old_flag == 0) {
3094                         done_word(&temp, &ctx);
3095                         done_pipe(&ctx,PIPE_SEQ);
3096 #ifndef __U_BOOT__
3097                         run_list(ctx.list_head);
3098 #else
3099                         if (((code = run_list(ctx.list_head)) == -1))
3100                             flag_repeat = 0;
3101 #endif
3102                 } else {
3103                         if (ctx.old_flag != 0) {
3104                                 free(ctx.stack);
3105                                 b_reset(&temp);
3106                         }
3107 #ifdef __U_BOOT__
3108                         if (inp->__promptme == 0) printf("<INTERRUPT>\n");
3109                         inp->__promptme = 1;
3110 #endif
3111                         temp.nonnull = 0;
3112                         temp.quote = 0;
3113                         inp->p = NULL;
3114                         free_pipe_list(ctx.list_head,0);
3115                 }
3116                 b_free(&temp);
3117         } while (rcode != -1 && !(flag & FLAG_EXIT_FROM_LOOP));   /* loop on syntax errors, return on EOF */
3118 #ifndef __U_BOOT__
3119         return 0;
3120 #else
3121         return (code != 0) ? 1 : 0;
3122 #endif /* __U_BOOT__ */
3123 }
3124
3125 #ifndef __U_BOOT__
3126 static int parse_string_outer(const char *s, int flag)
3127 #else
3128 int parse_string_outer(char *s, int flag)
3129 #endif  /* __U_BOOT__ */
3130 {
3131         struct in_str input;
3132 #ifdef __U_BOOT__
3133         char *p = NULL;
3134         int rcode;
3135         if ( !s || !*s)
3136                 return 1;
3137         if (!(p = strchr(s, '\n')) || *++p) {
3138                 p = xmalloc(strlen(s) + 2);
3139                 strcpy(p, s);
3140                 strcat(p, "\n");
3141                 setup_string_in_str(&input, p);
3142                 rcode = parse_stream_outer(&input, flag);
3143                 free(p);
3144                 return rcode;
3145         } else {
3146 #endif
3147         setup_string_in_str(&input, s);
3148         return parse_stream_outer(&input, flag);
3149 #ifdef __U_BOOT__
3150         }
3151 #endif
3152 }
3153
3154 #ifndef __U_BOOT__
3155 static int parse_file_outer(FILE *f)
3156 #else
3157 int parse_file_outer(void)
3158 #endif
3159 {
3160         int rcode;
3161         struct in_str input;
3162 #ifndef __U_BOOT__
3163         setup_file_in_str(&input, f);
3164 #else
3165         setup_file_in_str(&input);
3166 #endif
3167         rcode = parse_stream_outer(&input, FLAG_PARSE_SEMICOLON);
3168         return rcode;
3169 }
3170
3171 #ifdef __U_BOOT__
3172 int u_boot_hush_start(void)
3173 {
3174         top_vars = malloc(sizeof(struct variables));
3175         top_vars->name = "HUSH_VERSION";
3176         top_vars->value = "0.01";
3177         top_vars->next = 0;
3178         top_vars->flg_export = 0;
3179         top_vars->flg_read_only = 1;
3180         return 0;
3181 }
3182
3183 static void *xmalloc(size_t size)
3184 {
3185         void *p = NULL;
3186
3187         if (!(p = malloc(size))) {
3188             printf("ERROR : memory not allocated\n");
3189             for(;;);
3190         }
3191         return p;
3192 }
3193
3194 static void *xrealloc(void *ptr, size_t size)
3195 {
3196         void *p = NULL;
3197
3198         if (!(p = realloc(ptr, size))) {
3199             printf("ERROR : memory not allocated\n");
3200             for(;;);
3201         }
3202         return p;
3203 }
3204 #endif /* __U_BOOT__ */
3205
3206 #ifndef __U_BOOT__
3207 /* Make sure we have a controlling tty.  If we get started under a job
3208  * aware app (like bash for example), make sure we are now in charge so
3209  * we don't fight over who gets the foreground */
3210 static void setup_job_control(void)
3211 {
3212         static pid_t shell_pgrp;
3213         /* Loop until we are in the foreground.  */
3214         while (tcgetpgrp (shell_terminal) != (shell_pgrp = getpgrp ()))
3215                 kill (- shell_pgrp, SIGTTIN);
3216
3217         /* Ignore interactive and job-control signals.  */
3218         signal(SIGINT, SIG_IGN);
3219         signal(SIGQUIT, SIG_IGN);
3220         signal(SIGTERM, SIG_IGN);
3221         signal(SIGTSTP, SIG_IGN);
3222         signal(SIGTTIN, SIG_IGN);
3223         signal(SIGTTOU, SIG_IGN);
3224         signal(SIGCHLD, SIG_IGN);
3225
3226         /* Put ourselves in our own process group.  */
3227         setsid();
3228         shell_pgrp = getpid ();
3229         setpgid (shell_pgrp, shell_pgrp);
3230
3231         /* Grab control of the terminal.  */
3232         tcsetpgrp(shell_terminal, shell_pgrp);
3233 }
3234
3235 int hush_main(int argc, char **argv)
3236 {
3237         int opt;
3238         FILE *input;
3239         char **e = environ;
3240
3241         /* XXX what should these be while sourcing /etc/profile? */
3242         global_argc = argc;
3243         global_argv = argv;
3244
3245         /* (re?) initialize globals.  Sometimes hush_main() ends up calling
3246          * hush_main(), therefore we cannot rely on the BSS to zero out this
3247          * stuff.  Reset these to 0 every time. */
3248         ifs = NULL;
3249         /* map[] is taken care of with call to update_ifs_map() */
3250         fake_mode = 0;
3251         interactive = 0;
3252         close_me_head = NULL;
3253         last_bg_pid = 0;
3254         job_list = NULL;
3255         last_jobid = 0;
3256
3257         /* Initialize some more globals to non-zero values */
3258         set_cwd();
3259 #ifdef CONFIG_FEATURE_COMMAND_EDITING
3260         cmdedit_set_initial_prompt();
3261 #else
3262         PS1 = NULL;
3263 #endif
3264         PS2 = "> ";
3265
3266         /* initialize our shell local variables with the values
3267          * currently living in the environment */
3268         if (e) {
3269                 for (; *e; e++)
3270                         set_local_var(*e, 2);   /* without call putenv() */
3271         }
3272
3273         last_return_code=EXIT_SUCCESS;
3274
3275
3276         if (argv[0] && argv[0][0] == '-') {
3277                 debug_printf("\nsourcing /etc/profile\n");
3278                 if ((input = fopen("/etc/profile", "r")) != NULL) {
3279                         mark_open(fileno(input));
3280                         parse_file_outer(input);
3281                         mark_closed(fileno(input));
3282                         fclose(input);
3283                 }
3284         }
3285         input=stdin;
3286
3287         while ((opt = getopt(argc, argv, "c:xif")) > 0) {
3288                 switch (opt) {
3289                         case 'c':
3290                                 {
3291                                         global_argv = argv+optind;
3292                                         global_argc = argc-optind;
3293                                         opt = parse_string_outer(optarg, FLAG_PARSE_SEMICOLON);
3294                                         goto final_return;
3295                                 }
3296                                 break;
3297                         case 'i':
3298                                 interactive++;
3299                                 break;
3300                         case 'f':
3301                                 fake_mode++;
3302                                 break;
3303                         default:
3304 #ifndef BB_VER
3305                                 fprintf(stderr, "Usage: sh [FILE]...\n"
3306                                                 "   or: sh -c command [args]...\n\n");
3307                                 exit(EXIT_FAILURE);
3308 #else
3309                                 show_usage();
3310 #endif
3311                 }
3312         }
3313         /* A shell is interactive if the `-i' flag was given, or if all of
3314          * the following conditions are met:
3315          *        no -c command
3316          *    no arguments remaining or the -s flag given
3317          *    standard input is a terminal
3318          *    standard output is a terminal
3319          *    Refer to Posix.2, the description of the `sh' utility. */
3320         if (argv[optind]==NULL && input==stdin &&
3321                         isatty(fileno(stdin)) && isatty(fileno(stdout))) {
3322                 interactive++;
3323         }
3324
3325         debug_printf("\ninteractive=%d\n", interactive);
3326         if (interactive) {
3327                 /* Looks like they want an interactive shell */
3328 #ifndef CONFIG_FEATURE_SH_EXTRA_QUIET
3329                 printf( "\n\n" BB_BANNER " hush - the humble shell v0.01 (testing)\n");
3330                 printf( "Enter 'help' for a list of built-in commands.\n\n");
3331 #endif
3332                 setup_job_control();
3333         }
3334
3335         if (argv[optind]==NULL) {
3336                 opt=parse_file_outer(stdin);
3337                 goto final_return;
3338         }
3339
3340         debug_printf("\nrunning script '%s'\n", argv[optind]);
3341         global_argv = argv+optind;
3342         global_argc = argc-optind;
3343         input = xfopen(argv[optind], "r");
3344         opt = parse_file_outer(input);
3345
3346 #ifdef CONFIG_FEATURE_CLEAN_UP
3347         fclose(input);
3348         if (cwd && cwd != unknown)
3349                 free((char*)cwd);
3350         {
3351                 struct variables *cur, *tmp;
3352                 for(cur = top_vars; cur; cur = tmp) {
3353                         tmp = cur->next;
3354                         if (!cur->flg_read_only) {
3355                                 free(cur->name);
3356                                 free(cur->value);
3357                                 free(cur);
3358                         }
3359                 }
3360         }
3361 #endif
3362
3363 final_return:
3364         return(opt?opt:last_return_code);
3365 }
3366 #endif
3367
3368 static char *insert_var_value(char *inp)
3369 {
3370         int res_str_len = 0;
3371         int len;
3372         int done = 0;
3373         char *p, *p1, *res_str = NULL;
3374
3375         while ((p = strchr(inp, SPECIAL_VAR_SYMBOL))) {
3376                 if (p != inp) {
3377                         len = p - inp;
3378                         res_str = xrealloc(res_str, (res_str_len + len));
3379                         strncpy((res_str + res_str_len), inp, len);
3380                         res_str_len += len;
3381                 }
3382                 inp = ++p;
3383                 p = strchr(inp, SPECIAL_VAR_SYMBOL);
3384                 *p = '\0';
3385                 if ((p1 = lookup_param(inp))) {
3386                         len = res_str_len + strlen(p1);
3387                         res_str = xrealloc(res_str, (1 + len));
3388                         strcpy((res_str + res_str_len), p1);
3389                         res_str_len = len;
3390                 }
3391                 *p = SPECIAL_VAR_SYMBOL;
3392                 inp = ++p;
3393                 done = 1;
3394         }
3395         if (done) {
3396                 res_str = xrealloc(res_str, (1 + res_str_len + strlen(inp)));
3397                 strcpy((res_str + res_str_len), inp);
3398                 while ((p = strchr(res_str, '\n'))) {
3399                         *p = ' ';
3400                 }
3401         }
3402         return (res_str == NULL) ? inp : res_str;
3403 }
3404
3405 static char **make_list_in(char **inp, char *name)
3406 {
3407         int len, i;
3408         int name_len = strlen(name);
3409         int n = 0;
3410         char **list;
3411         char *p1, *p2, *p3;
3412
3413         /* create list of variable values */
3414         list = xmalloc(sizeof(*list));
3415         for (i = 0; inp[i]; i++) {
3416                 p3 = insert_var_value(inp[i]);
3417                 p1 = p3;
3418                 while (*p1) {
3419                         if ((*p1 == ' ')) {
3420                                 p1++;
3421                                 continue;
3422                         }
3423                         if ((p2 = strchr(p1, ' '))) {
3424                                 len = p2 - p1;
3425                         } else {
3426                                 len = strlen(p1);
3427                                 p2 = p1 + len;
3428                         }
3429                         /* we use n + 2 in realloc for list,because we add
3430                          * new element and then we will add NULL element */
3431                         list = xrealloc(list, sizeof(*list) * (n + 2));
3432                         list[n] = xmalloc(2 + name_len + len);
3433                         strcpy(list[n], name);
3434                         strcat(list[n], "=");
3435                         strncat(list[n], p1, len);
3436                         list[n++][name_len + len + 1] = '\0';
3437                         p1 = p2;
3438                 }
3439                 if (p3 != inp[i]) free(p3);
3440         }
3441         list[n] = NULL;
3442         return list;
3443 }
3444
3445 /* Make new string for parser */
3446 static char * make_string(char ** inp)
3447 {
3448         char *p;
3449         char *str = NULL;
3450         int n;
3451         int len = 2;
3452
3453         for (n = 0; inp[n]; n++) {
3454                 p = insert_var_value(inp[n]);
3455                 str = xrealloc(str, (len + strlen(p)));
3456                 if (n) {
3457                         strcat(str, " ");
3458                 } else {
3459                         *str = '\0';
3460                 }
3461                 strcat(str, p);
3462                 len = strlen(str) + 3;
3463                 if (p != inp[n]) free(p);
3464         }
3465         len = strlen(str);
3466         *(str + len) = '\n';
3467         *(str + len + 1) = '\0';
3468         return str;
3469 }
3470
3471 #endif /* CFG_HUSH_PARSER */
3472 /****************************************************************************/