1 /* vi: set sw=4 ts=4: */
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.
8 * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
11 * The parser routines proper are all original material, first
12 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
13 * execution engine, the builtins, and much of the underlying
14 * support has been adapted from busybox-0.49pre's lash, which is
15 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
16 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
17 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
18 * Troan, which they placed in the public domain. I don't know
19 * how much of the Johnson/Troan code has survived the repeated
23 * b_addchr() derived from similar w_addchar function in glibc-2.2
24 * setup_redirect(), redirect_opt_num(), and big chunks of main()
25 * and many builtins derived from contributions by Erik Andersen
26 * miscellaneous bugfixes from Matt Kraai
28 * There are two big (and related) architecture differences between
29 * this parser and the lash parser. One is that this version is
30 * actually designed from the ground up to understand nearly all
31 * of the Bourne grammar. The second, consequential change is that
32 * the parser and input reader have been turned inside out. Now,
33 * the parser is in control, and asks for input as needed. The old
34 * way had the input reader in control, and it asked for parsing to
35 * take place as needed. The new way makes it much easier to properly
36 * handle the recursion implicit in the various substitutions, especially
37 * across continuation lines.
39 * Bash grammar not implemented: (how many of these were in original sh?)
41 * ! negation operator for pipes
42 * &> and >& redirection of stdout+stderr
45 * fancy forms of Parameter Expansion
47 * Arithmetic Expansion
48 * <(list) and >(list) Process Substitution
49 * reserved words: case, esac, select, function
50 * Here Documents ( << word )
53 * job handling woefully incomplete and buggy (improved --vda)
54 * reserved word execution woefully incomplete and buggy
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
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 charmap[] to use 2-bit entries
74 * (eventually) remove all the printf's
76 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
80 #include <glob.h> /* glob, of course */
81 #include <getopt.h> /* should be pretty obvious */
82 /* #include <dmalloc.h> */
84 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
87 #if !BB_MMU && ENABLE_HUSH_TICK
88 //#undef ENABLE_HUSH_TICK
89 //#define ENABLE_HUSH_TICK 0
90 #warning On NOMMU, hush command substitution is dangerous.
91 #warning Dont use it for commands which produce lots of output.
92 #warning For more info see shell/hush.c, generate_stream_from_list().
95 #if !BB_MMU && ENABLE_HUSH_JOB
96 #undef ENABLE_HUSH_JOB
97 #define ENABLE_HUSH_JOB 0
100 #if !ENABLE_HUSH_INTERACTIVE
101 #undef ENABLE_FEATURE_EDITING
102 #define ENABLE_FEATURE_EDITING 0
103 #undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
104 #define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
108 /* If you comment out one of these below, it will be #defined later
109 * to perform debug printfs to stderr: */
110 #define debug_printf(...) do {} while (0)
111 /* Finer-grained debug switches */
112 #define debug_printf_parse(...) do {} while (0)
113 #define debug_print_tree(a, b) do {} while (0)
114 #define debug_printf_exec(...) do {} while (0)
115 #define debug_printf_jobs(...) do {} while (0)
116 #define debug_printf_expand(...) do {} while (0)
117 #define debug_printf_clean(...) do {} while (0)
120 #define debug_printf(...) fprintf(stderr, __VA_ARGS__)
123 #ifndef debug_printf_parse
124 #define debug_printf_parse(...) fprintf(stderr, __VA_ARGS__)
127 #ifndef debug_printf_exec
128 #define debug_printf_exec(...) fprintf(stderr, __VA_ARGS__)
131 #ifndef debug_printf_jobs
132 #define debug_printf_jobs(...) fprintf(stderr, __VA_ARGS__)
133 #define DEBUG_SHELL_JOBS 1
136 #ifndef debug_printf_expand
137 #define debug_printf_expand(...) fprintf(stderr, __VA_ARGS__)
138 #define DEBUG_EXPAND 1
141 /* Keep unconditionally on for now */
142 #define ENABLE_HUSH_DEBUG 1
144 #ifndef debug_printf_clean
145 /* broken, of course, but OK for testing */
146 static const char *indenter(int i)
148 static const char blanks[] ALIGN1 =
150 return &blanks[sizeof(blanks) - i - 1];
152 #define debug_printf_clean(...) fprintf(stderr, __VA_ARGS__)
153 #define DEBUG_CLEAN 1
158 * Leak hunting. Use hush_leaktool.sh for post-processing.
160 #ifdef FOR_HUSH_LEAKTOOL
161 void *xxmalloc(int lineno, size_t size)
163 void *ptr = xmalloc((size + 0xff) & ~0xff);
164 fprintf(stderr, "line %d: malloc %p\n", lineno, ptr);
167 void *xxrealloc(int lineno, void *ptr, size_t size)
169 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
170 fprintf(stderr, "line %d: realloc %p\n", lineno, ptr);
173 char *xxstrdup(int lineno, const char *str)
175 char *ptr = xstrdup(str);
176 fprintf(stderr, "line %d: strdup %p\n", lineno, ptr);
179 void xxfree(void *ptr)
181 fprintf(stderr, "free %p\n", ptr);
184 #define xmalloc(s) xxmalloc(__LINE__, s)
185 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
186 #define xstrdup(s) xxstrdup(__LINE__, s)
187 #define free(p) xxfree(p)
191 #define SPECIAL_VAR_SYMBOL 3
193 #define PARSEFLAG_EXIT_FROM_LOOP 1
194 #define PARSEFLAG_SEMICOLON (1 << 1) /* symbol ';' is special for parser */
195 #define PARSEFLAG_REPARSING (1 << 2) /* >= 2nd pass */
199 REDIRECT_OVERWRITE = 2,
205 /* The descrip member of this structure is only used to make debugging
207 static const struct {
209 signed char default_fd;
213 { O_RDONLY, 0, "<" },
214 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
215 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
216 { O_RDONLY, -1, "<<" },
227 /* might eventually control execution */
237 #if ENABLE_HUSH_LOOPS
249 FLAG_END = (1 << RES_NONE ),
251 FLAG_IF = (1 << RES_IF ),
252 FLAG_THEN = (1 << RES_THEN ),
253 FLAG_ELIF = (1 << RES_ELIF ),
254 FLAG_ELSE = (1 << RES_ELSE ),
255 FLAG_FI = (1 << RES_FI ),
257 #if ENABLE_HUSH_LOOPS
258 FLAG_FOR = (1 << RES_FOR ),
259 FLAG_WHILE = (1 << RES_WHILE),
260 FLAG_UNTIL = (1 << RES_UNTIL),
261 FLAG_DO = (1 << RES_DO ),
262 FLAG_DONE = (1 << RES_DONE ),
263 FLAG_IN = (1 << RES_IN ),
265 FLAG_START = (1 << RES_XXXX ),
268 /* This holds pointers to the various results of parsing */
270 struct child_prog *child;
271 struct pipe *list_head;
273 struct redir_struct *pending_redirect;
275 smallint parse_type; /* bitmask of PARSEFLAG_xxx, defines type of parser : ";$" common or special symbol */
276 int old_flag; /* bitmask of FLAG_xxx, for figuring out valid reserved words */
277 struct p_context *stack;
278 /* How about quoting status? */
281 struct redir_struct {
282 struct redir_struct *next; /* pointer to the next redirect in the list */
283 redir_type type; /* type of redirection */
284 int fd; /* file descriptor being redirected */
285 int dup; /* -1, or file descriptor being duplicated */
286 char **glob_word; /* *word.gl_pathv is the filename */
290 pid_t pid; /* 0 if exited */
291 char **argv; /* program name and arguments */
292 struct pipe *group; /* if non-NULL, first in group or subshell */
293 smallint subshell; /* flag, non-zero if group must be forked */
294 smallint is_stopped; /* is the program currently running? */
295 struct redir_struct *redirects; /* I/O redirections */
296 struct pipe *family; /* pointer back to the child's parent pipe */
297 //sp counting seems to be broken... so commented out, grep for '//sp:'
298 //sp: int sp; /* number of SPECIAL_VAR_SYMBOL */
299 //seems to be unused, grep for '//pt:'
300 //pt: int parse_type;
302 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
303 * and on execution these are substituted with their values.
304 * Substitution can make _several_ words out of one argv[n]!
305 * Example: argv[0]=='.^C*^C.' here: echo .$*.
310 int num_progs; /* total number of programs in job */
311 int running_progs; /* number of programs running (not exited) */
312 int stopped_progs; /* number of programs alive, but stopped */
314 int jobid; /* job number */
315 pid_t pgrp; /* process group ID for the job */
316 char *cmdtext; /* name of job */
318 char *cmdbuf; /* buffer various argv's point into */
319 struct child_prog *progs; /* array of commands in pipe */
320 int job_context; /* bitmask defining current context */
321 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
322 smallint res_word; /* needed for if, for, while, until... */
325 /* On program start, environ points to initial environment.
326 * putenv adds new pointers into it, unsetenv removes them.
327 * Neither of these (de)allocates the strings.
328 * setenv allocates new strings in malloc space and does putenv,
329 * and thus setenv is unusable (leaky) for shell's purposes */
330 #define setenv(...) setenv_is_leaky_dont_use()
332 struct variable *next;
333 char *varstr; /* points to "name=" portion */
334 int max_len; /* if > 0, name is part of initial env; else name is malloced */
335 smallint flg_export; /* putenv should be done on this var */
336 smallint flg_read_only;
346 #define NULL_O_STRING {NULL,0,0,0,0}
347 /* used for initialization: o_string foo = NULL_O_STRING; */
349 /* I can almost use ordinary FILE *. Is open_memstream() universally
350 * available? Where is it documented? */
353 /* eof_flag=1: last char in ->p is really an EOF */
354 char eof_flag; /* meaningless if ->p == NULL */
356 #if ENABLE_HUSH_INTERACTIVE
358 smallint promptmode; /* 0: PS1, 1: PS2 */
361 int (*get) (struct in_str *);
362 int (*peek) (struct in_str *);
364 #define b_getch(input) ((input)->get(input))
365 #define b_peek(input) ((input)->peek(input))
369 CHAR_ORDINARY_IF_QUOTED = 1, /* example: *, # */
370 CHAR_IFS = 2, /* treated as ordinary if quoted */
371 CHAR_SPECIAL = 3, /* example: $ */
374 #define HUSH_VER_STR "0.02"
376 /* "Globals" within this file */
378 /* Sorted roughly by size (smaller offsets == smaller code) */
380 #if ENABLE_HUSH_INTERACTIVE
381 /* 'interactive_fd' is a fd# open to ctty, if we have one
382 * _AND_ if we decided to act interactively */
387 #if ENABLE_FEATURE_EDITING
388 line_input_t *line_input_state;
392 pid_t saved_task_pgrp;
393 pid_t saved_tty_pgrp;
395 struct pipe *job_list;
396 struct pipe *toplevel_list;
397 smallint ctrl_z_flag;
400 /* these three support $?, $#, and $1 */
403 int last_return_code;
406 unsigned last_bg_pid;
407 struct variable *top_var; /* = &shell_ver (set in main()) */
408 struct variable shell_ver;
409 #if ENABLE_FEATURE_SH_STANDALONE
410 struct nofork_save_area nofork_save;
413 sigjmp_buf toplevel_jb;
415 unsigned char charmap[256];
416 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
419 #define G (*ptr_to_globals)
421 #if !ENABLE_HUSH_INTERACTIVE
422 enum { interactive_fd = 0 };
425 enum { run_list_level = 0 };
428 #if ENABLE_HUSH_INTERACTIVE
429 #define interactive_fd (G.interactive_fd )
433 #if ENABLE_FEATURE_EDITING
434 #define line_input_state (G.line_input_state)
437 #define run_list_level (G.run_list_level )
438 #define saved_task_pgrp (G.saved_task_pgrp )
439 #define saved_tty_pgrp (G.saved_tty_pgrp )
440 #define last_jobid (G.last_jobid )
441 #define job_list (G.job_list )
442 #define toplevel_list (G.toplevel_list )
443 #define toplevel_jb (G.toplevel_jb )
444 #define ctrl_z_flag (G.ctrl_z_flag )
446 #define global_argv (G.global_argv )
447 #define global_argc (G.global_argc )
448 #define last_return_code (G.last_return_code)
450 #define fake_mode (G.fake_mode )
452 #define last_bg_pid (G.last_bg_pid )
453 #define top_var (G.top_var )
454 #define shell_ver (G.shell_ver )
455 #if ENABLE_FEATURE_SH_STANDALONE
456 #define nofork_save (G.nofork_save )
459 #define toplevel_jb (G.toplevel_jb )
461 #define charmap (G.charmap )
462 #define user_input_buf (G.user_input_buf )
463 #define INIT_G() do { \
464 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
470 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
474 static void syntax(const char *msg)
476 /* Was using fancy stuff:
477 * (interactive_fd ? bb_error_msg : bb_error_msg_and_die)(...params...)
478 * but it SEGVs. ?! Oh well... explicit temp ptr works around that */
479 void (*fp)(const char *s, ...);
481 fp = (interactive_fd ? bb_error_msg : bb_error_msg_and_die);
482 fp(msg ? "%s: %s" : "syntax error", "syntax error", msg);
487 static void syntax_lineno(int line)
489 void (*fp)(const char *s, ...);
491 fp = (interactive_fd ? bb_error_msg : bb_error_msg_and_die);
492 fp("syntax error hush.c:%d", line);
494 #define syntax(str) syntax_lineno(__LINE__)
497 /* Index of subroutines: */
498 /* o_string manipulation: */
499 static int b_check_space(o_string *o, int len);
500 static int b_addchr(o_string *o, int ch);
501 static void b_reset(o_string *o);
502 static int b_addqchr(o_string *o, int ch, int quote);
503 /* in_str manipulations: */
504 static int static_get(struct in_str *i);
505 static int static_peek(struct in_str *i);
506 static int file_get(struct in_str *i);
507 static int file_peek(struct in_str *i);
508 static void setup_file_in_str(struct in_str *i, FILE *f);
509 static void setup_string_in_str(struct in_str *i, const char *s);
510 /* "run" the final data structures: */
511 #if !defined(DEBUG_CLEAN)
512 #define free_pipe_list(head, indent) free_pipe_list(head)
513 #define free_pipe(pi, indent) free_pipe(pi)
515 static int free_pipe_list(struct pipe *head, int indent);
516 static int free_pipe(struct pipe *pi, int indent);
517 /* really run the final data structures: */
518 static int setup_redirects(struct child_prog *prog, int squirrel[]);
519 static int run_list(struct pipe *pi);
520 static void pseudo_exec_argv(char **argv) ATTRIBUTE_NORETURN;
521 static void pseudo_exec(struct child_prog *child) ATTRIBUTE_NORETURN;
522 static int run_pipe(struct pipe *pi);
523 /* extended glob support: */
524 static char **globhack(const char *src, char **strings);
525 static int glob_needed(const char *s);
526 static int xglob(o_string *dest, char ***pglob);
527 /* variable assignment: */
528 static int is_assignment(const char *s);
529 /* data structure manipulation: */
530 static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
531 static void initialize_context(struct p_context *ctx);
532 static int done_word(o_string *dest, struct p_context *ctx);
533 static int done_command(struct p_context *ctx);
534 static int done_pipe(struct p_context *ctx, pipe_style type);
535 /* primary string parsing: */
536 static int redirect_dup_num(struct in_str *input);
537 static int redirect_opt_num(o_string *o);
539 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, const char *subst_end);
541 static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch);
542 static const char *lookup_param(const char *src);
543 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input);
544 static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, const char *end_trigger);
546 static int parse_and_run_stream(struct in_str *inp, int parse_flag);
547 static int parse_and_run_string(const char *s, int parse_flag);
548 static int parse_and_run_file(FILE *f);
549 /* job management: */
550 static int checkjobs(struct pipe* fg_pipe);
552 static int checkjobs_and_fg_shell(struct pipe* fg_pipe);
553 static void insert_bg_job(struct pipe *pi);
554 static void remove_bg_job(struct pipe *pi);
555 static void delete_finished_bg_job(struct pipe *pi);
557 int checkjobs_and_fg_shell(struct pipe* fg_pipe); /* never called */
559 /* local variable support */
560 static char **expand_strvec_to_strvec(char **argv);
562 static char *expand_strvec_to_string(char **argv);
563 /* used for expansion of right hand of assignments */
564 static char *expand_string_to_string(const char *str);
565 static struct variable *get_local_var(const char *name);
566 static int set_local_var(char *str, int flg_export);
567 static void unset_local_var(const char *name);
570 static char **add_strings_to_strings(int need_xstrdup, char **strings, char **add)
591 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
592 v[count1 + count2] = NULL;
595 v[count1 + i] = need_xstrdup ? xstrdup(add[i]) : add[i];
599 /* 'add' should be a malloced pointer */
600 static char **add_string_to_strings(char **strings, char *add)
607 return add_strings_to_strings(0, strings, v);
610 static void free_strings(char **strings)
621 /* Function prototypes for builtins */
622 static int builtin_cd(char **argv);
623 static int builtin_echo(char **argv);
624 static int builtin_eval(char **argv);
625 static int builtin_exec(char **argv);
626 static int builtin_exit(char **argv);
627 static int builtin_export(char **argv);
629 static int builtin_fg_bg(char **argv);
630 static int builtin_jobs(char **argv);
633 static int builtin_help(char **argv);
635 static int builtin_pwd(char **argv);
636 static int builtin_read(char **argv);
637 static int builtin_test(char **argv);
638 static int builtin_set(char **argv);
639 static int builtin_shift(char **argv);
640 static int builtin_source(char **argv);
641 static int builtin_umask(char **argv);
642 static int builtin_unset(char **argv);
643 //static int builtin_not_written(char **argv);
645 /* Table of built-in functions. They can be forked or not, depending on
646 * context: within pipes, they fork. As simple commands, they do not.
647 * When used in non-forking context, they can change global variables
648 * in the parent shell process. If forked, of course they cannot.
649 * For example, 'unset foo | whatever' will parse and run, but foo will
650 * still be set at the end. */
651 struct built_in_command {
652 const char *cmd; /* name */
653 int (*function) (char **argv); /* function ptr */
655 const char *descr; /* description */
656 #define BLTIN(cmd, func, help) { cmd, func, help }
658 #define BLTIN(cmd, func, help) { cmd, func }
662 /* For now, echo and test are unconditionally enabled.
663 * Maybe make it configurable? */
664 static const struct built_in_command bltins[] = {
665 BLTIN("[" , builtin_test, "Test condition"),
666 BLTIN("[[" , builtin_test, "Test condition"),
668 BLTIN("bg" , builtin_fg_bg, "Resume a job in the background"),
670 // BLTIN("break" , builtin_not_written, "Exit for, while or until loop"),
671 BLTIN("cd" , builtin_cd, "Change working directory"),
672 // BLTIN("continue", builtin_not_written, "Continue for, while or until loop"),
673 BLTIN("echo" , builtin_echo, "Write strings to stdout"),
674 BLTIN("eval" , builtin_eval, "Construct and run shell command"),
675 BLTIN("exec" , builtin_exec, "Exec command, replacing this shell with the exec'd process"),
676 BLTIN("exit" , builtin_exit, "Exit from shell"),
677 BLTIN("export", builtin_export, "Set environment variable"),
679 BLTIN("fg" , builtin_fg_bg, "Bring job into the foreground"),
680 BLTIN("jobs" , builtin_jobs, "Lists the active jobs"),
682 // TODO: remove pwd? we have it as an applet...
683 BLTIN("pwd" , builtin_pwd, "Print current directory"),
684 BLTIN("read" , builtin_read, "Input environment variable"),
685 // BLTIN("return", builtin_not_written, "Return from a function"),
686 BLTIN("set" , builtin_set, "Set/unset shell local variables"),
687 BLTIN("shift" , builtin_shift, "Shift positional parameters"),
688 // BLTIN("trap" , builtin_not_written, "Trap signals"),
689 BLTIN("test" , builtin_test, "Test condition"),
690 // BLTIN("ulimit", builtin_not_written, "Controls resource limits"),
691 BLTIN("umask" , builtin_umask, "Sets file creation mask"),
692 BLTIN("unset" , builtin_unset, "Unset environment variable"),
693 BLTIN("." , builtin_source, "Source-in and run commands in a file"),
695 BLTIN("help" , builtin_help, "List shell built-in commands"),
697 BLTIN(NULL, NULL, NULL)
702 /* Signals are grouped, we handle them in batches */
703 static void set_fatal_sighandler(void (*handler)(int))
712 /* bash 3.2 seems to handle these just like 'fatal' ones */
718 static void set_jobctrl_sighandler(void (*handler)(int))
726 static void set_misc_sighandler(void (*handler)(int))
734 /* SIGCHLD is special and handled separately */
736 static void set_every_sighandler(void (*handler)(int))
738 set_fatal_sighandler(handler);
739 set_jobctrl_sighandler(handler);
740 set_misc_sighandler(handler);
741 signal(SIGCHLD, handler);
744 static void handler_ctrl_c(int sig)
746 debug_printf_jobs("got sig %d\n", sig);
747 // as usual we can have all kinds of nasty problems with leaked malloc data here
748 siglongjmp(toplevel_jb, 1);
751 static void handler_ctrl_z(int sig)
755 debug_printf_jobs("got tty sig %d in pid %d\n", sig, getpid());
757 if (pid < 0) /* can't fork. Pretend there was no ctrl-Z */
760 if (!pid) { /* child */
762 die_sleep = 0; /* let nofork's xfuncs die */
764 debug_printf_jobs("set pgrp for child %d ok\n", getpid());
765 set_every_sighandler(SIG_DFL);
766 raise(SIGTSTP); /* resend TSTP so that child will be stopped */
767 debug_printf_jobs("returning in child\n");
768 /* return to nofork, it will eventually exit now,
769 * not return back to shell */
773 /* finish filling up pipe info */
774 toplevel_list->pgrp = pid; /* child is in its own pgrp */
775 toplevel_list->progs[0].pid = pid;
776 /* parent needs to longjmp out of running nofork.
777 * we will "return" exitcode 0, with child put in background */
778 // as usual we can have all kinds of nasty problems with leaked malloc data here
779 debug_printf_jobs("siglongjmp in parent\n");
780 siglongjmp(toplevel_jb, 1);
783 /* Restores tty foreground process group, and exits.
784 * May be called as signal handler for fatal signal
785 * (will faithfully resend signal to itself, producing correct exit state)
786 * or called directly with -EXITCODE.
787 * We also call it if xfunc is exiting. */
788 static void sigexit(int sig) ATTRIBUTE_NORETURN;
789 static void sigexit(int sig)
793 /* Disable all signals: job control, SIGPIPE, etc. */
794 sigfillset(&block_all);
795 sigprocmask(SIG_SETMASK, &block_all, NULL);
798 tcsetpgrp(interactive_fd, saved_tty_pgrp);
800 /* Not a signal, just exit */
804 kill_myself_with_sig(sig); /* does not return */
807 /* Restores tty foreground process group, and exits. */
808 static void hush_exit(int exitcode) ATTRIBUTE_NORETURN;
809 static void hush_exit(int exitcode)
811 fflush(NULL); /* flush all streams */
812 sigexit(- (exitcode & 0xff));
817 #define set_fatal_sighandler(handler) ((void)0)
818 #define set_jobctrl_sighandler(handler) ((void)0)
819 #define set_misc_sighandler(handler) ((void)0)
820 #define hush_exit(e) exit(e)
825 static const char *set_cwd(void)
827 if (cwd == bb_msg_unknown)
828 cwd = NULL; /* xrealloc_getcwd_or_warn(arg) calls free(arg)! */
829 cwd = xrealloc_getcwd_or_warn((char *)cwd);
831 cwd = bb_msg_unknown;
836 /* built-in 'test' handler */
837 static int builtin_test(char **argv)
844 return test_main(argc, argv - argc);
847 /* built-in 'test' handler */
848 static int builtin_echo(char **argv)
855 return echo_main(argc, argv - argc);
858 /* built-in 'eval' handler */
859 static int builtin_eval(char **argv)
861 int rcode = EXIT_SUCCESS;
864 char *str = expand_strvec_to_string(argv + 1);
865 parse_and_run_string(str, PARSEFLAG_EXIT_FROM_LOOP |
866 PARSEFLAG_SEMICOLON);
868 rcode = last_return_code;
873 /* built-in 'cd <path>' handler */
874 static int builtin_cd(char **argv)
877 if (argv[1] == NULL) {
878 // bash does nothing (exitcode 0) if HOME is ""; if it's unset,
879 // bash says "bash: cd: HOME not set" and does nothing (exitcode 1)
880 newdir = getenv("HOME") ? : "/";
884 printf("cd: %s: %s\n", newdir, strerror(errno));
891 /* built-in 'exec' handler */
892 static int builtin_exec(char **argv)
895 return EXIT_SUCCESS; /* Really? */
896 pseudo_exec_argv(argv + 1);
900 /* built-in 'exit' handler */
901 static int builtin_exit(char **argv)
903 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
904 //puts("exit"); /* bash does it */
905 // TODO: warn if we have background jobs: "There are stopped jobs"
906 // On second consecutive 'exit', exit anyway.
909 hush_exit(last_return_code);
910 /* mimic bash: exit 123abc == exit 255 + error msg */
911 xfunc_error_retval = 255;
912 /* bash: exit -2 == exit 254, no error msg */
913 hush_exit(xatoi(argv[1]) & 0xff);
916 /* built-in 'export VAR=value' handler */
917 static int builtin_export(char **argv)
920 char *name = argv[1];
924 // ash emits: export VAR='VAL'
925 // bash: declare -x VAR="VAL"
926 // (both also escape as needed (quotes, $, etc))
934 value = strchr(name, '=');
936 /* They are exporting something without a =VALUE */
937 struct variable *var;
939 var = get_local_var(name);
944 /* bash does not return an error when trying to export
945 * an undefined variable. Do likewise. */
949 set_local_var(xstrdup(name), 1);
954 /* built-in 'fg' and 'bg' handler */
955 static int builtin_fg_bg(char **argv)
962 /* If they gave us no args, assume they want the last backgrounded task */
964 for (pi = job_list; pi; pi = pi->next) {
965 if (pi->jobid == last_jobid) {
969 bb_error_msg("%s: no current job", argv[0]);
972 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
973 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
976 for (pi = job_list; pi; pi = pi->next) {
977 if (pi->jobid == jobnum) {
981 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
984 // TODO: bash prints a string representation
985 // of job being foregrounded (like "sleep 1 | cat")
986 if (*argv[0] == 'f') {
987 /* Put the job into the foreground. */
988 tcsetpgrp(interactive_fd, pi->pgrp);
991 /* Restart the processes in the job */
992 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_progs, pi->pgrp);
993 for (i = 0; i < pi->num_progs; i++) {
994 debug_printf_jobs("reviving pid %d\n", pi->progs[i].pid);
995 pi->progs[i].is_stopped = 0;
997 pi->stopped_progs = 0;
999 i = kill(- pi->pgrp, SIGCONT);
1001 if (errno == ESRCH) {
1002 delete_finished_bg_job(pi);
1003 return EXIT_SUCCESS;
1005 bb_perror_msg("kill (SIGCONT)");
1009 if (*argv[0] == 'f') {
1011 return checkjobs_and_fg_shell(pi);
1013 return EXIT_SUCCESS;
1017 /* built-in 'help' handler */
1018 #if ENABLE_HUSH_HELP
1019 static int builtin_help(char **argv ATTRIBUTE_UNUSED)
1021 const struct built_in_command *x;
1023 printf("\nBuilt-in commands:\n");
1024 printf("-------------------\n");
1025 for (x = bltins; x->cmd; x++) {
1026 printf("%s\t%s\n", x->cmd, x->descr);
1029 return EXIT_SUCCESS;
1034 /* built-in 'jobs' handler */
1035 static int builtin_jobs(char **argv ATTRIBUTE_UNUSED)
1038 const char *status_string;
1040 for (job = job_list; job; job = job->next) {
1041 if (job->running_progs == job->stopped_progs)
1042 status_string = "Stopped";
1044 status_string = "Running";
1046 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
1048 return EXIT_SUCCESS;
1052 /* built-in 'pwd' handler */
1053 static int builtin_pwd(char **argv ATTRIBUTE_UNUSED)
1056 return EXIT_SUCCESS;
1059 /* built-in 'read VAR' handler */
1060 static int builtin_read(char **argv)
1063 const char *name = argv[1] ? argv[1] : "REPLY";
1065 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name));
1066 return set_local_var(string, 0);
1069 /* built-in 'set [VAR=value]' handler */
1070 static int builtin_set(char **argv)
1072 char *temp = argv[1];
1076 for (e = top_var; e; e = e->next)
1079 set_local_var(xstrdup(temp), 0);
1081 return EXIT_SUCCESS;
1085 /* Built-in 'shift' handler */
1086 static int builtin_shift(char **argv)
1092 if (n >= 0 && n < global_argc) {
1093 global_argv[n] = global_argv[0];
1096 return EXIT_SUCCESS;
1098 return EXIT_FAILURE;
1101 /* Built-in '.' handler (read-in and execute commands from file) */
1102 static int builtin_source(char **argv)
1107 if (argv[1] == NULL)
1108 return EXIT_FAILURE;
1110 /* XXX search through $PATH is missing */
1111 input = fopen(argv[1], "r");
1113 bb_error_msg("cannot open '%s'", argv[1]);
1114 return EXIT_FAILURE;
1116 close_on_exec_on(fileno(input));
1118 /* Now run the file */
1119 /* XXX argv and argc are broken; need to save old global_argv
1120 * (pointer only is OK!) on this stack frame,
1121 * set global_argv=argv+1, recurse, and restore. */
1122 status = parse_and_run_file(input);
1127 static int builtin_umask(char **argv)
1130 const char *arg = argv[1];
1133 new_umask = strtoul(arg, &end, 8);
1134 if (*end != '\0' || end == arg) {
1135 return EXIT_FAILURE;
1138 new_umask = umask(0);
1139 printf("%.3o\n", (unsigned) new_umask);
1142 return EXIT_SUCCESS;
1145 /* built-in 'unset VAR' handler */
1146 static int builtin_unset(char **argv)
1148 /* bash always returns true */
1149 unset_local_var(argv[1]);
1150 return EXIT_SUCCESS;
1153 //static int builtin_not_written(char **argv)
1155 // printf("builtin_%s not written\n", argv[0]);
1156 // return EXIT_FAILURE;
1159 static int b_check_space(o_string *o, int len)
1161 /* It would be easy to drop a more restrictive policy
1162 * in here, such as setting a maximum string length */
1163 if (o->length + len > o->maxlen) {
1164 /* assert(data == NULL || o->maxlen != 0); */
1165 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1166 o->data = xrealloc(o->data, 1 + o->maxlen);
1168 return o->data == NULL;
1171 static int b_addchr(o_string *o, int ch)
1173 debug_printf("b_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1174 if (b_check_space(o, 1))
1176 o->data[o->length] = ch;
1178 o->data[o->length] = '\0';
1182 static void b_reset(o_string *o)
1190 static void b_free(o_string *o)
1193 memset(o, 0, sizeof(*o));
1196 /* My analysis of quoting semantics tells me that state information
1197 * is associated with a destination, not a source.
1199 static int b_addqchr(o_string *o, int ch, int quote)
1201 if (quote && strchr("*?[\\", ch)) {
1203 rc = b_addchr(o, '\\');
1207 return b_addchr(o, ch);
1210 static int static_get(struct in_str *i)
1213 if (ch == '\0') return EOF;
1217 static int static_peek(struct in_str *i)
1222 #if ENABLE_HUSH_INTERACTIVE
1223 #if ENABLE_FEATURE_EDITING
1224 static void cmdedit_set_initial_prompt(void)
1226 #if !ENABLE_FEATURE_EDITING_FANCY_PROMPT
1229 PS1 = getenv("PS1");
1234 #endif /* EDITING */
1236 static const char* setup_prompt_string(int promptmode)
1238 const char *prompt_str;
1239 debug_printf("setup_prompt_string %d ", promptmode);
1240 #if !ENABLE_FEATURE_EDITING_FANCY_PROMPT
1241 /* Set up the prompt */
1242 if (promptmode == 0) { /* PS1 */
1244 PS1 = xasprintf("%s %c ", cwd, (geteuid() != 0) ? '$' : '#');
1250 prompt_str = (promptmode == 0) ? PS1 : PS2;
1252 debug_printf("result '%s'\n", prompt_str);
1256 static void get_user_input(struct in_str *i)
1259 const char *prompt_str;
1261 prompt_str = setup_prompt_string(i->promptmode);
1262 #if ENABLE_FEATURE_EDITING
1263 /* Enable command line editing only while a command line
1264 * is actually being read */
1266 r = read_line_input(prompt_str, user_input_buf, BUFSIZ-1, line_input_state);
1267 } while (r == 0); /* repeat if Ctrl-C */
1268 i->eof_flag = (r < 0);
1269 if (i->eof_flag) { /* EOF/error detected */
1270 user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1271 user_input_buf[1] = '\0';
1274 fputs(prompt_str, stdout);
1276 user_input_buf[0] = r = fgetc(i->file);
1277 /*user_input_buf[1] = '\0'; - already is and never changed */
1278 i->eof_flag = (r == EOF);
1280 i->p = user_input_buf;
1282 #endif /* INTERACTIVE */
1284 /* This is the magic location that prints prompts
1285 * and gets data back from the user */
1286 static int file_get(struct in_str *i)
1290 /* If there is data waiting, eat it up */
1291 if (i->p && *i->p) {
1292 #if ENABLE_HUSH_INTERACTIVE
1296 if (i->eof_flag && !*i->p)
1299 /* need to double check i->file because we might be doing something
1300 * more complicated by now, like sourcing or substituting. */
1301 #if ENABLE_HUSH_INTERACTIVE
1302 if (interactive_fd && i->promptme && i->file == stdin) {
1305 } while (!*i->p); /* need non-empty line */
1306 i->promptmode = 1; /* PS2 */
1311 ch = fgetc(i->file);
1313 debug_printf("file_get: got a '%c' %d\n", ch, ch);
1314 #if ENABLE_HUSH_INTERACTIVE
1321 /* All the callers guarantee this routine will never be
1322 * used right after a newline, so prompting is not needed.
1324 static int file_peek(struct in_str *i)
1327 if (i->p && *i->p) {
1328 if (i->eof_flag && !i->p[1])
1332 ch = fgetc(i->file);
1333 i->eof_flag = (ch == EOF);
1334 i->peek_buf[0] = ch;
1335 i->peek_buf[1] = '\0';
1337 debug_printf("file_peek: got a '%c' %d\n", *i->p, *i->p);
1341 static void setup_file_in_str(struct in_str *i, FILE *f)
1343 i->peek = file_peek;
1345 #if ENABLE_HUSH_INTERACTIVE
1347 i->promptmode = 0; /* PS1 */
1353 static void setup_string_in_str(struct in_str *i, const char *s)
1355 i->peek = static_peek;
1356 i->get = static_get;
1357 #if ENABLE_HUSH_INTERACTIVE
1359 i->promptmode = 0; /* PS1 */
1365 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
1366 * and stderr if they are redirected. */
1367 static int setup_redirects(struct child_prog *prog, int squirrel[])
1370 struct redir_struct *redir;
1372 for (redir = prog->redirects; redir; redir = redir->next) {
1373 if (redir->dup == -1 && redir->glob_word == NULL) {
1374 /* something went wrong in the parse. Pretend it didn't happen */
1377 if (redir->dup == -1) {
1379 mode = redir_table[redir->type].mode;
1380 p = expand_string_to_string(redir->glob_word[0]);
1381 openfd = open_or_warn(p, mode);
1384 /* this could get lost if stderr has been redirected, but
1385 bash and ash both lose it as well (though zsh doesn't!) */
1389 openfd = redir->dup;
1392 if (openfd != redir->fd) {
1393 if (squirrel && redir->fd < 3) {
1394 squirrel[redir->fd] = dup(redir->fd);
1397 //close(openfd); // close(-3) ??!
1399 dup2(openfd, redir->fd);
1400 if (redir->dup == -1)
1408 static void restore_redirects(int squirrel[])
1411 for (i = 0; i < 3; i++) {
1414 /* We simply die on error */
1420 /* Called after [v]fork() in run_pipe(), or from builtin_exec().
1422 * XXX no exit() here. If you don't exec, use _exit instead.
1423 * The at_exit handlers apparently confuse the calling process,
1424 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
1425 static void pseudo_exec_argv(char **argv)
1429 const struct built_in_command *x;
1431 for (i = 0; is_assignment(argv[i]); i++) {
1432 debug_printf_exec("pid %d environment modification: %s\n",
1434 // FIXME: vfork case??
1435 p = expand_string_to_string(argv[i]);
1439 /* If a variable is assigned in a forest, and nobody listens,
1440 * was it ever really set?
1443 _exit(EXIT_SUCCESS);
1445 argv = expand_strvec_to_strvec(argv);
1448 * Check if the command matches any of the builtins.
1449 * Depending on context, this might be redundant. But it's
1450 * easier to waste a few CPU cycles than it is to figure out
1451 * if this is one of those cases.
1453 for (x = bltins; x->cmd; x++) {
1454 if (strcmp(argv[0], x->cmd) == 0) {
1455 debug_printf_exec("running builtin '%s'\n", argv[0]);
1456 rcode = x->function(argv);
1462 /* Check if the command matches any busybox applets */
1463 #if ENABLE_FEATURE_SH_STANDALONE
1464 if (strchr(argv[0], '/') == NULL) {
1465 int a = find_applet_by_name(argv[0]);
1467 if (APPLET_IS_NOEXEC(a)) {
1468 debug_printf_exec("running applet '%s'\n", argv[0]);
1469 // is it ok that run_applet_no_and_exit() does exit(), not _exit()?
1470 run_applet_no_and_exit(a, argv);
1472 /* re-exec ourselves with the new arguments */
1473 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
1474 execvp(bb_busybox_exec_path, argv);
1475 /* If they called chroot or otherwise made the binary no longer
1476 * executable, fall through */
1481 debug_printf_exec("execing '%s'\n", argv[0]);
1482 execvp(argv[0], argv);
1483 bb_perror_msg("cannot exec '%s'", argv[0]);
1487 /* Called after [v]fork() in run_pipe()
1489 static void pseudo_exec(struct child_prog *child)
1491 // FIXME: buggy wrt NOMMU! Must not modify any global data
1492 // until it does exec/_exit, but currently it does
1493 // (puts malloc'ed stuff into environment)
1495 pseudo_exec_argv(child->argv);
1499 bb_error_msg_and_die("nested lists are not supported on NOMMU");
1503 #if ENABLE_HUSH_INTERACTIVE
1504 // run_list_level now takes care of it?
1505 // debug_printf_exec("pseudo_exec: setting interactive_fd=0\n");
1506 // interactive_fd = 0; /* crucial!!!! */
1508 debug_printf_exec("pseudo_exec: run_list\n");
1509 rcode = run_list(child->group);
1510 /* OK to leak memory by not calling free_pipe_list,
1511 * since this process is about to exit */
1516 /* Can happen. See what bash does with ">foo" by itself. */
1517 debug_printf("trying to pseudo_exec null command\n");
1518 _exit(EXIT_SUCCESS);
1522 static const char *get_cmdtext(struct pipe *pi)
1528 /* This is subtle. ->cmdtext is created only on first backgrounding.
1529 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
1530 * On subsequent bg argv is trashed, but we won't use it */
1533 argv = pi->progs[0].argv;
1534 if (!argv || !argv[0])
1535 return (pi->cmdtext = xzalloc(1));
1538 do len += strlen(*argv) + 1; while (*++argv);
1539 pi->cmdtext = p = xmalloc(len);
1540 argv = pi->progs[0].argv;
1542 len = strlen(*argv);
1543 memcpy(p, *argv, len);
1551 static void insert_bg_job(struct pipe *pi)
1553 struct pipe *thejob;
1556 /* Linear search for the ID of the job to use */
1558 for (thejob = job_list; thejob; thejob = thejob->next)
1559 if (thejob->jobid >= pi->jobid)
1560 pi->jobid = thejob->jobid + 1;
1562 /* Add thejob to the list of running jobs */
1564 thejob = job_list = xmalloc(sizeof(*thejob));
1566 for (thejob = job_list; thejob->next; thejob = thejob->next)
1568 thejob->next = xmalloc(sizeof(*thejob));
1569 thejob = thejob->next;
1572 /* Physically copy the struct job */
1573 memcpy(thejob, pi, sizeof(struct pipe));
1574 thejob->progs = xzalloc(sizeof(pi->progs[0]) * pi->num_progs);
1575 /* We cannot copy entire pi->progs[] vector! Double free()s will happen */
1576 for (i = 0; i < pi->num_progs; i++) {
1577 // TODO: do we really need to have so many fields which are just dead weight
1578 // at execution stage?
1579 thejob->progs[i].pid = pi->progs[i].pid;
1580 /* all other fields are not used and stay zero */
1582 thejob->next = NULL;
1583 thejob->cmdtext = xstrdup(get_cmdtext(pi));
1585 /* We don't wait for background thejobs to return -- append it
1586 to the list of backgrounded thejobs and leave it alone */
1587 printf("[%d] %d %s\n", thejob->jobid, thejob->progs[0].pid, thejob->cmdtext);
1588 last_bg_pid = thejob->progs[0].pid;
1589 last_jobid = thejob->jobid;
1592 static void remove_bg_job(struct pipe *pi)
1594 struct pipe *prev_pipe;
1596 if (pi == job_list) {
1597 job_list = pi->next;
1599 prev_pipe = job_list;
1600 while (prev_pipe->next != pi)
1601 prev_pipe = prev_pipe->next;
1602 prev_pipe->next = pi->next;
1605 last_jobid = job_list->jobid;
1610 /* remove a backgrounded job */
1611 static void delete_finished_bg_job(struct pipe *pi)
1614 pi->stopped_progs = 0;
1620 /* Checks to see if any processes have exited -- if they
1621 have, figure out why and see if a job has completed */
1622 static int checkjobs(struct pipe* fg_pipe)
1633 attributes = WUNTRACED;
1634 if (fg_pipe == NULL) {
1635 attributes |= WNOHANG;
1638 /* Do we do this right?
1639 * bash-3.00# sleep 20 | false
1641 * [3]+ Stopped sleep 20 | false
1642 * bash-3.00# echo $?
1643 * 1 <========== bg pipe is not fully done, but exitcode is already known!
1646 //FIXME: non-interactive bash does not continue even if all processes in fg pipe
1647 //are stopped. Testcase: "cat | cat" in a script (not on command line)
1648 // + killall -STOP cat
1651 // TODO: safe_waitpid?
1652 while ((childpid = waitpid(-1, &status, attributes)) > 0) {
1653 const int dead = WIFEXITED(status) || WIFSIGNALED(status);
1655 #ifdef DEBUG_SHELL_JOBS
1656 if (WIFSTOPPED(status))
1657 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
1658 childpid, WSTOPSIG(status), WEXITSTATUS(status));
1659 if (WIFSIGNALED(status))
1660 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
1661 childpid, WTERMSIG(status), WEXITSTATUS(status));
1662 if (WIFEXITED(status))
1663 debug_printf_jobs("pid %d exited, exitcode %d\n",
1664 childpid, WEXITSTATUS(status));
1666 /* Were we asked to wait for fg pipe? */
1669 for (i = 0; i < fg_pipe->num_progs; i++) {
1670 debug_printf_jobs("check pid %d\n", fg_pipe->progs[i].pid);
1671 if (fg_pipe->progs[i].pid == childpid) {
1672 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
1674 fg_pipe->progs[i].pid = 0;
1675 fg_pipe->running_progs--;
1676 if (i == fg_pipe->num_progs - 1)
1677 /* last process gives overall exitstatus */
1678 rcode = WEXITSTATUS(status);
1680 fg_pipe->progs[i].is_stopped = 1;
1681 fg_pipe->stopped_progs++;
1683 debug_printf_jobs("fg_pipe: running_progs %d stopped_progs %d\n",
1684 fg_pipe->running_progs, fg_pipe->stopped_progs);
1685 if (fg_pipe->running_progs - fg_pipe->stopped_progs <= 0) {
1686 /* All processes in fg pipe have exited/stopped */
1688 if (fg_pipe->running_progs)
1689 insert_bg_job(fg_pipe);
1693 /* There are still running processes in the fg pipe */
1697 /* fall through to searching process in bg pipes */
1701 /* We asked to wait for bg or orphaned children */
1702 /* No need to remember exitcode in this case */
1703 for (pi = job_list; pi; pi = pi->next) {
1705 while (prognum < pi->num_progs) {
1706 if (pi->progs[prognum].pid == childpid)
1707 goto found_pi_and_prognum;
1713 /* Happens when shell is used as init process (init=/bin/sh) */
1714 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
1718 found_pi_and_prognum:
1721 pi->progs[prognum].pid = 0;
1722 pi->running_progs--;
1723 if (!pi->running_progs) {
1724 printf(JOB_STATUS_FORMAT, pi->jobid,
1725 "Done", pi->cmdtext);
1726 delete_finished_bg_job(pi);
1730 pi->stopped_progs++;
1731 pi->progs[prognum].is_stopped = 1;
1736 /* wait found no children or failed */
1738 if (childpid && errno != ECHILD)
1739 bb_perror_msg("waitpid");
1744 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
1747 int rcode = checkjobs(fg_pipe);
1748 /* Job finished, move the shell to the foreground */
1749 p = getpgid(0); /* pgid of our process */
1750 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
1751 if (tcsetpgrp(interactive_fd, p) && errno != ENOTTY)
1752 bb_perror_msg("tcsetpgrp-4a");
1757 /* run_pipe() starts all the jobs, but doesn't wait for anything
1758 * to finish. See checkjobs().
1760 * return code is normally -1, when the caller has to wait for children
1761 * to finish to determine the exit status of the pipe. If the pipe
1762 * is a simple builtin command, however, the action is done by the
1763 * time run_pipe returns, and the exit code is provided as the
1766 * The input of the pipe is always stdin, the output is always
1767 * stdout. The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
1768 * because it tries to avoid running the command substitution in
1769 * subshell, when that is in fact necessary. The subshell process
1770 * now has its stdout directed to the input of the appropriate pipe,
1771 * so this routine is noticeably simpler.
1773 * Returns -1 only if started some children. IOW: we have to
1774 * mask out retvals of builtins etc with 0xff!
1776 static int run_pipe(struct pipe *pi)
1780 int pipefds[2]; /* pipefds[0] is for reading */
1781 struct child_prog *child;
1782 const struct built_in_command *x;
1784 /* it is not always needed, but we aim to smaller code */
1785 int squirrel[] = { -1, -1, -1 };
1787 const int single_fg = (pi->num_progs == 1 && pi->followup != PIPE_BG);
1789 debug_printf_exec("run_pipe start: single_fg=%d\n", single_fg);
1794 pi->running_progs = 1;
1795 pi->stopped_progs = 0;
1797 /* Check if this is a simple builtin (not part of a pipe).
1798 * Builtins within pipes have to fork anyway, and are handled in
1799 * pseudo_exec. "echo foo | read bar" doesn't work on bash, either.
1801 child = &(pi->progs[0]);
1802 if (single_fg && child->group && child->subshell == 0) {
1803 debug_printf("non-subshell grouping\n");
1804 setup_redirects(child, squirrel);
1805 debug_printf_exec(": run_list\n");
1806 rcode = run_list(child->group) & 0xff;
1807 restore_redirects(squirrel);
1808 debug_printf_exec("run_pipe return %d\n", rcode);
1812 if (single_fg && child->argv != NULL) {
1813 char **argv_expanded;
1814 char **argv = child->argv;
1816 for (i = 0; is_assignment(argv[i]); i++)
1818 if (i != 0 && argv[i] == NULL) {
1819 /* assignments, but no command: set the local environment */
1820 for (i = 0; argv[i] != NULL; i++) {
1821 debug_printf("local environment set: %s\n", argv[i]);
1822 p = expand_string_to_string(argv[i]);
1823 set_local_var(p, 0);
1825 return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */
1827 for (i = 0; is_assignment(argv[i]); i++) {
1828 p = expand_string_to_string(argv[i]);
1832 for (x = bltins; x->cmd; x++) {
1833 if (strcmp(argv[i], x->cmd) == 0) {
1834 if (x->function == builtin_exec && argv[i+1] == NULL) {
1835 debug_printf("magic exec\n");
1836 setup_redirects(child, NULL);
1837 return EXIT_SUCCESS;
1839 debug_printf("builtin inline %s\n", argv[0]);
1840 /* XXX setup_redirects acts on file descriptors, not FILEs.
1841 * This is perfect for work that comes after exec().
1842 * Is it really safe for inline use? Experimentally,
1843 * things seem to work with glibc. */
1844 setup_redirects(child, squirrel);
1845 debug_printf_exec(": builtin '%s' '%s'...\n", x->cmd, argv[i+1]);
1846 //sp: if (child->sp) /* btw we can do it unconditionally... */
1847 argv_expanded = expand_strvec_to_strvec(argv + i);
1848 rcode = x->function(argv_expanded) & 0xff;
1849 free(argv_expanded);
1850 restore_redirects(squirrel);
1851 debug_printf_exec("run_pipe return %d\n", rcode);
1855 #if ENABLE_FEATURE_SH_STANDALONE
1857 int a = find_applet_by_name(argv[i]);
1858 if (a >= 0 && APPLET_IS_NOFORK(a)) {
1859 setup_redirects(child, squirrel);
1860 save_nofork_data(&nofork_save);
1861 argv_expanded = argv + i;
1862 //sp: if (child->sp)
1863 argv_expanded = expand_strvec_to_strvec(argv + i);
1864 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n", argv_expanded[0], argv_expanded[1]);
1865 rcode = run_nofork_applet_prime(&nofork_save, a, argv_expanded) & 0xff;
1866 free(argv_expanded);
1867 restore_redirects(squirrel);
1868 debug_printf_exec("run_pipe return %d\n", rcode);
1875 /* Disable job control signals for shell (parent) and
1876 * for initial child code after fork */
1877 set_jobctrl_sighandler(SIG_IGN);
1879 /* Going to fork a child per each pipe member */
1880 pi->running_progs = 0;
1883 for (i = 0; i < pi->num_progs; i++) {
1884 child = &(pi->progs[i]);
1886 debug_printf_exec(": pipe member '%s' '%s'...\n", child->argv[0], child->argv[1]);
1888 debug_printf_exec(": pipe member with no argv\n");
1890 /* pipes are inserted between pairs of commands */
1893 if ((i + 1) < pi->num_progs)
1896 child->pid = BB_MMU ? fork() : vfork();
1897 if (!child->pid) { /* child */
1898 if (ENABLE_HUSH_JOB)
1899 die_sleep = 0; /* let nofork's xfuncs die */
1901 /* Every child adds itself to new process group
1902 * with pgid == pid_of_first_child_in_pipe */
1903 if (run_list_level == 1 && interactive_fd) {
1905 /* Don't do pgrp restore anymore on fatal signals */
1906 set_fatal_sighandler(SIG_DFL);
1908 if (pgrp < 0) /* true for 1st process only */
1910 if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
1911 /* We do it in *every* child, not just first,
1913 tcsetpgrp(interactive_fd, pgrp);
1917 xmove_fd(nextin, 0);
1918 xmove_fd(pipefds[1], 1); /* write end */
1920 close(pipefds[0]); /* read end */
1921 /* Like bash, explicit redirects override pipes,
1922 * and the pipe fd is available for dup'ing. */
1923 setup_redirects(child, NULL);
1925 /* Restore default handlers just prior to exec */
1926 set_jobctrl_sighandler(SIG_DFL);
1927 set_misc_sighandler(SIG_DFL);
1928 signal(SIGCHLD, SIG_DFL);
1929 pseudo_exec(child); /* does not return */
1932 if (child->pid < 0) { /* [v]fork failed */
1933 /* Clearly indicate, was it fork or vfork */
1934 bb_perror_msg(BB_MMU ? "fork" : "vfork");
1936 pi->running_progs++;
1938 /* Second and next children need to know pid of first one */
1940 pi->pgrp = child->pid;
1946 if ((i + 1) < pi->num_progs)
1947 close(pipefds[1]); /* write end */
1948 /* Pass read (output) pipe end to next iteration */
1949 nextin = pipefds[0];
1952 if (!pi->running_progs) {
1953 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
1957 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->running_progs);
1961 #ifndef debug_print_tree
1962 static void debug_print_tree(struct pipe *pi, int lvl)
1964 static const char *PIPE[] = {
1970 static const char *RES[] = {
1971 [RES_NONE ] = "NONE" ,
1974 [RES_THEN ] = "THEN" ,
1975 [RES_ELIF ] = "ELIF" ,
1976 [RES_ELSE ] = "ELSE" ,
1979 #if ENABLE_HUSH_LOOPS
1980 [RES_FOR ] = "FOR" ,
1981 [RES_WHILE] = "WHILE",
1982 [RES_UNTIL] = "UNTIL",
1984 [RES_DONE ] = "DONE" ,
1987 [RES_XXXX ] = "XXXX" ,
1988 [RES_SNTX ] = "SNTX" ,
1995 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
1996 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
1998 while (prn < pi->num_progs) {
1999 struct child_prog *child = &pi->progs[prn];
2000 char **argv = child->argv;
2002 fprintf(stderr, "%*s prog %d", lvl*2, "", prn);
2004 fprintf(stderr, " group %s: (argv=%p)\n",
2005 (child->subshell ? "()" : "{}"),
2007 debug_print_tree(child->group, lvl+1);
2011 if (argv) while (*argv) {
2012 fprintf(stderr, " '%s'", *argv);
2015 fprintf(stderr, "\n");
2024 /* NB: called by pseudo_exec, and therefore must not modify any
2025 * global data until exec/_exit (we can be a child after vfork!) */
2026 static int run_list(struct pipe *pi)
2029 #if ENABLE_HUSH_LOOPS
2030 char *for_varname = NULL;
2031 char **for_lcur = NULL;
2032 char **for_list = NULL;
2036 int rcode = 0; /* probably for gcc only */
2037 int flag_restore = 0;
2039 int if_code = 0, next_if_code = 0; /* need double-buffer to handle elif */
2041 enum { if_code = 0, next_if_code = 0 };
2043 reserved_style rword;
2044 reserved_style skip_more_for_this_rword = RES_XXXX;
2046 debug_printf_exec("run_list start lvl %d\n", run_list_level + 1);
2048 #if ENABLE_HUSH_LOOPS
2049 /* check syntax for "for" */
2050 for (rpipe = pi; rpipe; rpipe = rpipe->next) {
2051 if ((rpipe->res_word == RES_IN || rpipe->res_word == RES_FOR)
2052 && (rpipe->next == NULL)
2054 syntax("malformed for"); /* no IN or no commands after IN */
2055 debug_printf_exec("run_list lvl %d return 1\n", run_list_level);
2058 if ((rpipe->res_word == RES_IN && rpipe->next->res_word == RES_IN && rpipe->next->progs[0].argv != NULL)
2059 || (rpipe->res_word == RES_FOR && rpipe->next->res_word != RES_IN)
2061 /* TODO: what is tested in the first condition? */
2062 syntax("malformed for"); /* 2nd condition: not followed by IN */
2063 debug_printf_exec("run_list lvl %d return 1\n", run_list_level);
2072 /* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
2073 * We are saving state before entering outermost list ("while...done")
2074 * so that ctrl-Z will correctly background _entire_ outermost list,
2075 * not just a part of it (like "sleep 1 | exit 2") */
2076 if (++run_list_level == 1 && interactive_fd) {
2077 if (sigsetjmp(toplevel_jb, 1)) {
2078 /* ctrl-Z forked and we are parent; or ctrl-C.
2079 * Sighandler has longjmped us here */
2080 signal(SIGINT, SIG_IGN);
2081 signal(SIGTSTP, SIG_IGN);
2082 /* Restore level (we can be coming from deep inside
2085 #if ENABLE_FEATURE_SH_STANDALONE
2086 if (nofork_save.saved) { /* if save area is valid */
2087 debug_printf_jobs("exiting nofork early\n");
2088 restore_nofork_data(&nofork_save);
2092 /* ctrl-Z has forked and stored pid of the child in pi->pid.
2093 * Remember this child as background job */
2096 /* ctrl-C. We just stop doing whatever we were doing */
2102 /* ctrl-Z handler will store pid etc in pi */
2105 #if ENABLE_FEATURE_SH_STANDALONE
2106 nofork_save.saved = 0; /* in case we will run a nofork later */
2108 signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z);
2109 signal(SIGINT, handler_ctrl_c);
2113 for (; pi; pi = flag_restore ? rpipe : pi->next) {
2114 //why? int save_num_progs;
2115 rword = pi->res_word;
2116 #if ENABLE_HUSH_LOOPS
2117 if (rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR) {
2125 debug_printf_exec(": rword=%d if_code=%d next_if_code=%d skip_more=%d\n",
2126 rword, if_code, next_if_code, skip_more_for_this_rword);
2127 if (rword == skip_more_for_this_rword && flag_skip) {
2128 if (pi->followup == PIPE_SEQ)
2133 skip_more_for_this_rword = RES_XXXX;
2135 if (rword == RES_THEN || rword == RES_ELSE)
2136 if_code = next_if_code;
2137 if (rword == RES_THEN && if_code)
2139 if (rword == RES_ELSE && !if_code)
2141 if (rword == RES_ELIF && !if_code)
2144 #if ENABLE_HUSH_LOOPS
2145 if (rword == RES_FOR && pi->num_progs) {
2147 /* first loop through for */
2148 /* if no variable values after "in" we skip "for" */
2149 if (!pi->next->progs->argv)
2151 /* create list of variable values */
2152 for_list = expand_strvec_to_strvec(pi->next->progs->argv);
2153 for_lcur = for_list;
2154 for_varname = pi->progs->argv[0];
2155 pi->progs->argv[0] = NULL;
2158 free(pi->progs->argv[0]);
2160 /* for loop is over, clean up */
2164 pi->progs->argv[0] = for_varname;
2167 /* insert next value from for_lcur */
2168 /* vda: does it need escaping? */
2169 pi->progs->argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
2171 if (rword == RES_IN)
2173 if (rword == RES_DO) {
2177 if (rword == RES_DONE) {
2185 if (pi->num_progs == 0)
2187 //why? save_num_progs = pi->num_progs;
2188 debug_printf_exec(": run_pipe with %d members\n", pi->num_progs);
2189 rcode = run_pipe(pi);
2191 /* We only ran a builtin: rcode was set by the return value
2192 * of run_pipe(), and we don't need to wait for anything. */
2193 } else if (pi->followup == PIPE_BG) {
2194 /* What does bash do with attempts to background builtins? */
2195 /* Even bash 3.2 doesn't do that well with nested bg:
2196 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
2197 * I'm NOT treating inner &'s as jobs */
2199 if (run_list_level == 1)
2202 rcode = EXIT_SUCCESS;
2205 if (run_list_level == 1 && interactive_fd) {
2206 /* waits for completion, then fg's main shell */
2207 rcode = checkjobs_and_fg_shell(pi);
2211 /* this one just waits for completion */
2212 rcode = checkjobs(pi);
2214 debug_printf_exec(": checkjobs returned %d\n", rcode);
2216 debug_printf_exec(": setting last_return_code=%d\n", rcode);
2217 last_return_code = rcode;
2218 //why? pi->num_progs = save_num_progs;
2220 if (rword == RES_IF || rword == RES_ELIF)
2221 next_if_code = rcode; /* can be overwritten a number of times */
2223 #if ENABLE_HUSH_LOOPS
2224 if (rword == RES_WHILE)
2225 flag_rep = !last_return_code;
2226 if (rword == RES_UNTIL)
2227 flag_rep = last_return_code;
2229 if ((rcode == EXIT_SUCCESS && pi->followup == PIPE_OR)
2230 || (rcode != EXIT_SUCCESS && pi->followup == PIPE_AND)
2232 skip_more_for_this_rword = rword;
2239 /* ctrl-Z forked somewhere in the past, we are the child,
2240 * and now we completed running the list. Exit. */
2244 if (!--run_list_level && interactive_fd) {
2245 signal(SIGTSTP, SIG_IGN);
2246 signal(SIGINT, SIG_IGN);
2249 debug_printf_exec("run_list lvl %d return %d\n", run_list_level + 1, rcode);
2253 /* return code is the exit status of the pipe */
2254 static int free_pipe(struct pipe *pi, int indent)
2257 struct child_prog *child;
2258 struct redir_struct *r, *rnext;
2259 int a, i, ret_code = 0;
2261 if (pi->stopped_progs > 0)
2263 debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid());
2264 for (i = 0; i < pi->num_progs; i++) {
2265 child = &pi->progs[i];
2266 debug_printf_clean("%s command %d:\n", indenter(indent), i);
2268 for (a = 0, p = child->argv; *p; a++, p++) {
2269 debug_printf_clean("%s argv[%d] = %s\n", indenter(indent), a, *p);
2271 free_strings(child->argv);
2273 } else if (child->group) {
2274 debug_printf_clean("%s begin group (subshell:%d)\n", indenter(indent), child->subshell);
2275 ret_code = free_pipe_list(child->group, indent+3);
2276 debug_printf_clean("%s end group\n", indenter(indent));
2278 debug_printf_clean("%s (nil)\n", indenter(indent));
2280 for (r = child->redirects; r; r = rnext) {
2281 debug_printf_clean("%s redirect %d%s", indenter(indent), r->fd, redir_table[r->type].descrip);
2283 /* guard against the case >$FOO, where foo is unset or blank */
2285 debug_printf_clean(" %s\n", r->glob_word[0]);
2286 free_strings(r->glob_word);
2287 r->glob_word = NULL;
2290 debug_printf_clean("&%d\n", r->dup);
2295 child->redirects = NULL;
2297 free(pi->progs); /* children are an array, they get freed all at once */
2306 static int free_pipe_list(struct pipe *head, int indent)
2308 int rcode = 0; /* if list has no members */
2309 struct pipe *pi, *next;
2311 for (pi = head; pi; pi = next) {
2312 debug_printf_clean("%s pipe reserved mode %d\n", indenter(indent), pi->res_word);
2313 rcode = free_pipe(pi, indent);
2314 debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup);
2316 /*pi->next = NULL;*/
2322 /* Select which version we will use */
2323 static int run_and_free_list(struct pipe *pi)
2326 debug_printf_exec("run_and_free_list entered\n");
2328 debug_printf_exec(": run_list with %d members\n", pi->num_progs);
2329 rcode = run_list(pi);
2331 /* free_pipe_list has the side effect of clearing memory.
2332 * In the long run that function can be merged with run_list,
2333 * but doing that now would hobble the debugging effort. */
2334 free_pipe_list(pi, /* indent: */ 0);
2335 debug_printf_exec("run_nad_free_list return %d\n", rcode);
2339 /* Whoever decided to muck with glob internal data is AN IDIOT! */
2340 /* uclibc happily changed the way it works (and it has rights to do so!),
2341 all hell broke loose (SEGVs) */
2343 /* The API for glob is arguably broken. This routine pushes a non-matching
2344 * string into the output structure, removing non-backslashed backslashes.
2345 * If someone can prove me wrong, by performing this function within the
2346 * original glob(3) api, feel free to rewrite this routine into oblivion.
2347 * XXX broken if the last character is '\\', check that before calling.
2349 static char **globhack(const char *src, char **strings)
2355 for (cnt = 1, s = src; s && *s; s++) {
2356 if (*s == '\\') s++;
2359 v = dest = xmalloc(cnt);
2360 for (s = src; s && *s; s++, dest++) {
2361 if (*s == '\\') s++;
2366 return add_string_to_strings(strings, v);
2369 /* XXX broken if the last character is '\\', check that before calling */
2370 static int glob_needed(const char *s)
2375 if (strchr("*[?", *s))
2381 static int xglob(o_string *dest, char ***pglob)
2383 /* short-circuit for null word */
2384 /* we can code this better when the debug_printf's are gone */
2385 if (dest->length == 0) {
2386 if (dest->nonnull) {
2387 /* bash man page calls this an "explicit" null */
2388 *pglob = globhack(dest->data, *pglob);
2393 if (glob_needed(dest->data)) {
2397 memset(&globdata, 0, sizeof(globdata));
2398 gr = glob(dest->data, 0, NULL, &globdata);
2399 debug_printf("glob returned %d\n", gr);
2400 if (gr == GLOB_NOSPACE)
2401 bb_error_msg_and_die("out of memory during glob");
2402 if (gr == GLOB_NOMATCH) {
2403 debug_printf("globhack returned %d\n", gr);
2404 /* quote removal, or more accurately, backslash removal */
2405 *pglob = globhack(dest->data, *pglob);
2406 globfree(&globdata);
2409 if (gr != 0) { /* GLOB_ABORTED ? */
2410 bb_error_msg("glob(3) error %d", gr);
2412 if (globdata.gl_pathv && globdata.gl_pathv[0])
2413 *pglob = add_strings_to_strings(1, *pglob, globdata.gl_pathv);
2414 globfree(&globdata);
2418 *pglob = globhack(dest->data, *pglob);
2422 /* expand_strvec_to_strvec() takes a list of strings, expands
2423 * all variable references within and returns a pointer to
2424 * a list of expanded strings, possibly with larger number
2425 * of strings. (Think VAR="a b"; echo $VAR).
2426 * This new list is allocated as a single malloc block.
2427 * NULL-terminated list of char* pointers is at the beginning of it,
2428 * followed by strings themself.
2429 * Caller can deallocate entire list by single free(list). */
2432 * count_XXX estimates size of the block we need. It's okay
2433 * to over-estimate sizes a bit, if it makes code simpler */
2434 static int count_ifs(const char *str)
2437 debug_printf_expand("count_ifs('%s') ifs='%s'", str, ifs);
2439 str += strcspn(str, ifs);
2441 str++; /* str += strspn(str, ifs); */
2442 cnt++; /* cnt += strspn(str, ifs); - but this code is larger */
2444 debug_printf_expand(" return %d\n", cnt);
2448 static void count_var_expansion_space(int *countp, int *lenp, char *arg)
2453 int count = *countp;
2457 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL))) {
2460 p = strchr(p, SPECIAL_VAR_SYMBOL);
2463 switch (first_ch & 0x7f) {
2464 /* high bit in 1st_ch indicates that var is double-quoted */
2466 case '!': /* bg pid */
2467 case '?': /* exitcode */
2468 case '#': /* argc */
2469 len += sizeof(int)*3 + 1; /* enough for int */
2473 for (i = 1; global_argv[i]; i++) {
2474 len += strlen(global_argv[i]) + 1;
2476 if (!(first_ch & 0x80))
2477 count += count_ifs(global_argv[i]);
2482 arg[0] = first_ch & 0x7f;
2483 if (isdigit(arg[0])) {
2486 if (i < global_argc)
2487 val = global_argv[i];
2489 val = lookup_param(arg);
2491 *p = SPECIAL_VAR_SYMBOL;
2494 len += strlen(val) + 1;
2495 if (!(first_ch & 0x80))
2496 count += count_ifs(val);
2502 len += strlen(arg) + 1;
2508 /* Store given string, finalizing the word and starting new one whenever
2509 * we encounter ifs char(s). This is used for expanding variable values.
2510 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
2511 static int expand_on_ifs(char **list, int n, char **posp, const char *str)
2515 int word_len = strcspn(str, ifs);
2517 memcpy(pos, str, word_len); /* store non-ifs chars */
2521 if (!*str) /* EOL - do not finalize word */
2524 if (n) debug_printf_expand("expand_on_ifs finalized list[%d]=%p '%s' "
2525 "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1],
2526 strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos);
2528 str += strspn(str, ifs); /* skip ifs chars */
2534 /* Expand all variable references in given string, adding words to list[]
2535 * at n, n+1,... positions. Return updated n (so that list[n] is next one
2536 * to be filled). This routine is extremely tricky: has to deal with
2537 * variables/parameters with whitespace, $* and $@, and constructs like
2538 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
2539 /* NB: another bug is that we cannot detect empty strings yet:
2540 * "" or $empty"" expands to zero words, has to expand to empty word */
2541 static int expand_vars_to_list(char **list, int n, char **posp, char *arg, char or_mask)
2543 /* or_mask is either 0 (normal case) or 0x80
2544 * (expansion of right-hand side of assignment == 1-element expand) */
2546 char first_ch, ored_ch;
2554 if (n) debug_printf_expand("expand_vars_to_list finalized list[%d]=%p '%s' "
2555 "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1],
2556 strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos);
2559 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL))) {
2560 memcpy(pos, arg, p - arg);
2563 p = strchr(p, SPECIAL_VAR_SYMBOL);
2565 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
2566 ored_ch |= first_ch;
2568 switch (first_ch & 0x7f) {
2569 /* Highest bit in first_ch indicates that var is double-quoted */
2571 /* FIXME: (echo $$) should still print pid of main shell */
2572 val = utoa(getpid()); /* rootpid? */
2574 case '!': /* bg pid */
2575 val = last_bg_pid ? utoa(last_bg_pid) : (char*)"";
2577 case '?': /* exitcode */
2578 val = utoa(last_return_code);
2580 case '#': /* argc */
2581 val = utoa(global_argc ? global_argc-1 : 0);
2586 if (!global_argv[i])
2588 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
2589 while (global_argv[i]) {
2590 n = expand_on_ifs(list, n, &pos, global_argv[i]);
2591 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, global_argc-1);
2592 if (global_argv[i++][0] && global_argv[i]) {
2593 /* this argv[] is not empty and not last:
2594 * put terminating NUL, start new word */
2596 if (n) debug_printf_expand("expand_vars_to_list 2 finalized list[%d]=%p '%s' "
2597 "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1],
2598 strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos);
2603 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
2604 * and in this case should treat it like '$*' - see 'else...' below */
2605 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
2607 strcpy(pos, global_argv[i]);
2608 pos += strlen(global_argv[i]);
2609 if (++i >= global_argc)
2612 if (n) debug_printf_expand("expand_vars_to_list 3 finalized list[%d]=%p '%s' "
2613 "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1],
2614 strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos);
2617 } else { /* quoted $*: add as one word */
2619 strcpy(pos, global_argv[i]);
2620 pos += strlen(global_argv[i]);
2621 if (!global_argv[++i])
2630 arg[0] = first_ch & 0x7f;
2631 if (isdigit(arg[0])) {
2634 if (i < global_argc)
2635 val = global_argv[i];
2637 val = lookup_param(arg);
2639 *p = SPECIAL_VAR_SYMBOL;
2640 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2642 n = expand_on_ifs(list, n, &pos, val);
2645 } /* else: quoted $VAR, val will be appended at pos */
2653 debug_printf_expand("expand_vars_to_list adding tail '%s' at %p\n", arg, pos);
2655 pos += strlen(arg) + 1;
2656 if (pos == list[n-1] + 1) { /* expansion is empty */
2657 if (!(ored_ch & 0x80)) { /* all vars were not quoted... */
2658 debug_printf_expand("expand_vars_to_list list[%d] empty, going back\n", n);
2668 static char **expand_variables(char **argv, char or_mask)
2673 char *pos, **v, **list;
2676 if (!*v) debug_printf_expand("count_var_expansion_space: "
2677 "argv[0]=NULL count=%d len=%d alloc_space=%d\n",
2678 count, len, sizeof(char*) * count + len);
2680 count_var_expansion_space(&count, &len, *v);
2681 debug_printf_expand("count_var_expansion_space: "
2682 "'%s' count=%d len=%d alloc_space=%d\n",
2683 *v, count, len, sizeof(char*) * count + len);
2686 len += sizeof(char*) * count; /* total to alloc */
2687 list = xmalloc(len);
2688 pos = (char*)(list + count);
2689 debug_printf_expand("list=%p, list[0] should be %p\n", list, pos);
2693 n = expand_vars_to_list(list, n, &pos, *v++, or_mask);
2695 if (n) debug_printf_expand("finalized list[%d]=%p '%s' "
2696 "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1],
2697 strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos);
2704 debug_printf_expand("list[%d]=%p '%s'\n", m, list[m], list[m]);
2707 debug_printf_expand("used_space=%d\n", pos - (char*)list);
2710 if (ENABLE_HUSH_DEBUG)
2711 if (pos - (char*)list > len)
2712 bb_error_msg_and_die("BUG in varexp");
2716 static char **expand_strvec_to_strvec(char **argv)
2718 return expand_variables(argv, 0);
2721 static char *expand_string_to_string(const char *str)
2723 char *argv[2], **list;
2725 argv[0] = (char*)str;
2727 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
2728 if (ENABLE_HUSH_DEBUG)
2729 if (!list[0] || list[1])
2730 bb_error_msg_and_die("BUG in varexp2");
2731 /* actually, just move string 2*sizeof(char*) bytes back */
2732 strcpy((char*)list, list[0]);
2733 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2737 static char* expand_strvec_to_string(char **argv)
2741 list = expand_variables(argv, 0x80);
2742 /* Convert all NULs to spaces */
2746 if (ENABLE_HUSH_DEBUG)
2747 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2748 bb_error_msg_and_die("BUG in varexp3");
2749 list[n][-1] = ' '; /* TODO: or to ifs[0]? */
2753 strcpy((char*)list, list[0]);
2754 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2758 /* This is used to get/check local shell variables */
2759 static struct variable *get_local_var(const char *name)
2761 struct variable *cur;
2767 for (cur = top_var; cur; cur = cur->next) {
2768 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
2774 /* str holds "NAME=VAL" and is expected to be malloced.
2775 * We take ownership of it. */
2776 static int set_local_var(char *str, int flg_export)
2778 struct variable *cur;
2782 value = strchr(str, '=');
2783 if (!value) { /* not expected to ever happen? */
2788 name_len = value - str + 1; /* including '=' */
2789 cur = top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
2791 if (strncmp(cur->varstr, str, name_len) != 0) {
2793 /* Bail out. Note that now cur points
2794 * to last var in linked list */
2800 /* We found an existing var with this name */
2802 if (cur->flg_read_only) {
2803 bb_error_msg("%s: readonly variable", str);
2807 unsetenv(str); /* just in case */
2809 if (strcmp(cur->varstr, str) == 0) {
2814 if (cur->max_len >= strlen(str)) {
2815 /* This one is from startup env, reuse space */
2816 strcpy(cur->varstr, str);
2819 /* max_len == 0 signifies "malloced" var, which we can
2820 * (and has to) free */
2824 goto set_str_and_exp;
2827 /* Not found - create next variable struct */
2828 cur->next = xzalloc(sizeof(*cur));
2835 cur->flg_export = 1;
2836 if (cur->flg_export)
2837 return putenv(cur->varstr);
2841 static void unset_local_var(const char *name)
2843 struct variable *cur;
2844 struct variable *prev = prev; /* for gcc */
2849 name_len = strlen(name);
2852 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
2853 if (cur->flg_read_only) {
2854 bb_error_msg("%s: readonly variable", name);
2857 /* prev is ok to use here because 1st variable, HUSH_VERSION,
2858 * is ro, and we cannot reach this code on the 1st pass */
2859 prev->next = cur->next;
2860 unsetenv(cur->varstr);
2871 static int is_assignment(const char *s)
2873 if (!s || !isalpha(*s))
2876 while (isalnum(*s) || *s == '_')
2881 /* the src parameter allows us to peek forward to a possible &n syntax
2882 * for file descriptor duplication, e.g., "2>&1".
2883 * Return code is 0 normally, 1 if a syntax error is detected in src.
2884 * Resource errors (in xmalloc) cause the process to exit */
2885 static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
2886 struct in_str *input)
2888 struct child_prog *child = ctx->child;
2889 struct redir_struct *redir = child->redirects;
2890 struct redir_struct *last_redir = NULL;
2892 /* Create a new redir_struct and drop it onto the end of the linked list */
2895 redir = redir->next;
2897 redir = xzalloc(sizeof(struct redir_struct));
2898 /* redir->next = NULL; */
2899 /* redir->glob_word = NULL; */
2901 last_redir->next = redir;
2903 child->redirects = redir;
2906 redir->type = style;
2907 redir->fd = (fd == -1) ? redir_table[style].default_fd : fd;
2909 debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
2911 /* Check for a '2>&1' type redirect */
2912 redir->dup = redirect_dup_num(input);
2913 if (redir->dup == -2) return 1; /* syntax error */
2914 if (redir->dup != -1) {
2915 /* Erik had a check here that the file descriptor in question
2916 * is legit; I postpone that to "run time"
2917 * A "-" representation of "close me" shows up as a -3 here */
2918 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
2920 /* We do _not_ try to open the file that src points to,
2921 * since we need to return and let src be expanded first.
2922 * Set ctx->pending_redirect, so we know what to do at the
2923 * end of the next parsed word. */
2924 ctx->pending_redirect = redir;
2929 static struct pipe *new_pipe(void)
2932 pi = xzalloc(sizeof(struct pipe));
2933 /*pi->num_progs = 0;*/
2934 /*pi->progs = NULL;*/
2935 /*pi->next = NULL;*/
2936 /*pi->followup = 0; invalid */
2938 pi->res_word = RES_NONE;
2942 static void initialize_context(struct p_context *ctx)
2945 ctx->pipe = ctx->list_head = new_pipe();
2946 ctx->pending_redirect = NULL;
2947 ctx->res_w = RES_NONE;
2948 //only ctx->parse_type is not touched... is this intentional?
2951 done_command(ctx); /* creates the memory for working child */
2954 /* normal return is 0
2955 * if a reserved word is found, and processed, return 1
2956 * should handle if, then, elif, else, fi, for, while, until, do, done.
2957 * case, function, and select are obnoxious, save those for later.
2959 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS
2960 static int reserved_word(o_string *dest, struct p_context *ctx)
2962 struct reserved_combo {
2967 /* Mostly a list of accepted follow-up reserved words.
2968 * FLAG_END means we are done with the sequence, and are ready
2969 * to turn the compound list into a command.
2970 * FLAG_START means the word must start a new compound list.
2972 static const struct reserved_combo reserved_list[] = {
2974 { "if", RES_IF, FLAG_THEN | FLAG_START },
2975 { "then", RES_THEN, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2976 { "elif", RES_ELIF, FLAG_THEN },
2977 { "else", RES_ELSE, FLAG_FI },
2978 { "fi", RES_FI, FLAG_END },
2980 #if ENABLE_HUSH_LOOPS
2981 { "for", RES_FOR, FLAG_IN | FLAG_START },
2982 { "while", RES_WHILE, FLAG_DO | FLAG_START },
2983 { "until", RES_UNTIL, FLAG_DO | FLAG_START },
2984 { "in", RES_IN, FLAG_DO },
2985 { "do", RES_DO, FLAG_DONE },
2986 { "done", RES_DONE, FLAG_END }
2990 const struct reserved_combo *r;
2992 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
2993 if (strcmp(dest->data, r->literal) != 0)
2995 debug_printf("found reserved word %s, code %d\n", r->literal, r->code);
2996 if (r->flag & FLAG_START) {
2997 struct p_context *new;
2998 debug_printf("push stack\n");
2999 #if ENABLE_HUSH_LOOPS
3000 if (ctx->res_w == RES_IN || ctx->res_w == RES_FOR) {
3001 syntax("malformed for"); /* example: 'for if' */
3002 ctx->res_w = RES_SNTX;
3007 new = xmalloc(sizeof(*new));
3008 *new = *ctx; /* physical copy */
3009 initialize_context(ctx);
3011 } else if (ctx->res_w == RES_NONE || !(ctx->old_flag & (1 << r->code))) {
3013 ctx->res_w = RES_SNTX;
3017 ctx->res_w = r->code;
3018 ctx->old_flag = r->flag;
3019 if (ctx->old_flag & FLAG_END) {
3020 struct p_context *old;
3021 debug_printf("pop stack\n");
3022 done_pipe(ctx, PIPE_SEQ);
3024 old->child->group = ctx->list_head;
3025 old->child->subshell = 0;
3026 *ctx = *old; /* physical copy */
3035 #define reserved_word(dest, ctx) ((int)0)
3038 /* Normal return is 0.
3039 * Syntax or xglob errors return 1. */
3040 static int done_word(o_string *dest, struct p_context *ctx)
3042 struct child_prog *child = ctx->child;
3043 char ***glob_target;
3046 debug_printf_parse("done_word entered: '%s' %p\n", dest->data, child);
3047 if (dest->length == 0 && !dest->nonnull) {
3048 debug_printf_parse("done_word return 0: true null, ignored\n");
3051 if (ctx->pending_redirect) {
3052 glob_target = &ctx->pending_redirect->glob_word;
3056 debug_printf_parse("done_word return 1: syntax error, groups and arglists don't mix\n");
3059 if (!child->argv && (ctx->parse_type & PARSEFLAG_SEMICOLON)) {
3060 debug_printf_parse(": checking '%s' for reserved-ness\n", dest->data);
3061 if (reserved_word(dest, ctx)) {
3062 debug_printf_parse("done_word return %d\n", (ctx->res_w == RES_SNTX));
3063 return (ctx->res_w == RES_SNTX);
3066 glob_target = &child->argv;
3068 gr = xglob(dest, glob_target);
3070 debug_printf_parse("done_word return 1: xglob returned %d\n", gr);
3075 if (ctx->pending_redirect) {
3076 /* NB: don't free_strings(ctx->pending_redirect->glob_word) here */
3077 if (ctx->pending_redirect->glob_word
3078 && ctx->pending_redirect->glob_word[0]
3079 && ctx->pending_redirect->glob_word[1]
3081 /* more than one word resulted from globbing redir */
3082 ctx->pending_redirect = NULL;
3083 bb_error_msg("ambiguous redirect");
3084 debug_printf_parse("done_word return 1: ambiguous redirect\n");
3087 ctx->pending_redirect = NULL;
3089 #if ENABLE_HUSH_LOOPS
3090 if (ctx->res_w == RES_FOR) {
3091 done_word(dest, ctx);
3092 done_pipe(ctx, PIPE_SEQ);
3095 debug_printf_parse("done_word return 0\n");
3099 /* The only possible error here is out of memory, in which case
3101 static int done_command(struct p_context *ctx)
3103 /* The child is really already in the pipe structure, so
3104 * advance the pipe counter and make a new, null child. */
3105 struct pipe *pi = ctx->pipe;
3106 struct child_prog *child = ctx->child;
3109 if (child->group == NULL
3110 && child->argv == NULL
3111 && child->redirects == NULL
3113 debug_printf_parse("done_command: skipping null cmd, num_progs=%d\n", pi->num_progs);
3114 return pi->num_progs;
3117 debug_printf_parse("done_command: ++num_progs=%d\n", pi->num_progs);
3119 debug_printf_parse("done_command: initializing, num_progs=%d\n", pi->num_progs);
3122 /* Only real trickiness here is that the uncommitted
3123 * child structure is not counted in pi->num_progs. */
3124 pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
3125 child = &pi->progs[pi->num_progs];
3127 memset(child, 0, sizeof(*child));
3128 /*child->redirects = NULL;*/
3129 /*child->argv = NULL;*/
3130 /*child->is_stopped = 0;*/
3131 /*child->group = NULL;*/
3133 //sp: /*child->sp = 0;*/
3134 //pt: child->parse_type = ctx->parse_type;
3137 /* but ctx->pipe and ctx->list_head remain unchanged */
3139 return pi->num_progs; /* used only for 0/nonzero check */
3142 static int done_pipe(struct p_context *ctx, pipe_style type)
3147 debug_printf_parse("done_pipe entered, followup %d\n", type);
3148 not_null = done_command(ctx); /* implicit closure of previous command */
3149 ctx->pipe->followup = type;
3150 ctx->pipe->res_word = ctx->res_w;
3151 /* Without this check, even just <enter> on command line generates
3152 * tree of three NOPs (!). Which is harmless but annoying.
3153 * IOW: it is safe to do it unconditionally. */
3156 ctx->pipe->next = new_p;
3159 done_command(ctx); /* set up new pipe to accept commands */
3161 debug_printf_parse("done_pipe return 0\n");
3165 /* peek ahead in the in_str to find out if we have a "&n" construct,
3166 * as in "2>&1", that represents duplicating a file descriptor.
3167 * returns either -2 (syntax error), -1 (no &), or the number found.
3169 static int redirect_dup_num(struct in_str *input)
3171 int ch, d = 0, ok = 0;
3173 if (ch != '&') return -1;
3175 b_getch(input); /* get the & */
3179 return -3; /* "-" represents "close me" */
3181 while (isdigit(ch)) {
3182 d = d*10 + (ch-'0');
3189 bb_error_msg("ambiguous redirect");
3193 /* If a redirect is immediately preceded by a number, that number is
3194 * supposed to tell which file descriptor to redirect. This routine
3195 * looks for such preceding numbers. In an ideal world this routine
3196 * needs to handle all the following classes of redirects...
3197 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3198 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3199 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3200 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3201 * A -1 output from this program means no valid number was found, so the
3202 * caller should use the appropriate default for this redirection.
3204 static int redirect_opt_num(o_string *o)
3210 for (num = 0; num < o->length; num++) {
3211 if (!isdigit(*(o->data + num))) {
3215 /* reuse num (and save an int) */
3216 num = atoi(o->data);
3221 #if ENABLE_HUSH_TICK
3222 /* NB: currently disabled on NOMMU */
3223 static FILE *generate_stream_from_list(struct pipe *head)
3226 int pid, channel[2];
3229 /* *** NOMMU WARNING *** */
3230 /* By using vfork here, we suspend parent till child exits or execs.
3231 * If child will not do it before it fills the pipe, it can block forever
3232 * in write(STDOUT_FILENO), and parent (shell) will be also stuck.
3234 pid = BB_MMU ? fork() : vfork();
3236 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
3237 if (pid == 0) { /* child */
3238 if (ENABLE_HUSH_JOB)
3239 die_sleep = 0; /* let nofork's xfuncs die */
3240 close(channel[0]); /* NB: close _first_, then move fd! */
3241 xmove_fd(channel[1], 1);
3242 /* Prevent it from trying to handle ctrl-z etc */
3246 /* Process substitution is not considered to be usual
3247 * 'command execution'.
3248 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not. */
3249 /* Not needed, we are relying on it being disabled
3250 * everywhere outside actual command execution. */
3251 /*set_jobctrl_sighandler(SIG_IGN);*/
3252 set_misc_sighandler(SIG_DFL);
3253 /* Freeing 'head' here would break NOMMU. */
3254 _exit(run_list(head));
3257 pf = fdopen(channel[0], "r");
3259 /* 'head' is freed by the caller */
3262 /* Return code is exit status of the process that is run. */
3263 static int process_command_subs(o_string *dest, struct p_context *ctx,
3264 struct in_str *input, const char *subst_end)
3266 int retcode, ch, eol_cnt;
3267 o_string result = NULL_O_STRING;
3268 struct p_context inner;
3270 struct in_str pipe_str;
3272 initialize_context(&inner);
3274 /* recursion to generate command */
3275 retcode = parse_stream(&result, &inner, input, subst_end);
3277 return retcode; /* syntax error or EOF */
3278 done_word(&result, &inner);
3279 done_pipe(&inner, PIPE_SEQ);
3282 p = generate_stream_from_list(inner.list_head);
3285 close_on_exec_on(fileno(p));
3286 setup_file_in_str(&pipe_str, p);
3288 /* now send results of command back into original context */
3290 while ((ch = b_getch(&pipe_str)) != EOF) {
3296 b_addqchr(dest, '\n', dest->o_quote);
3299 b_addqchr(dest, ch, dest->o_quote);
3302 debug_printf("done reading from pipe, pclose()ing\n");
3303 /* This is the step that wait()s for the child. Should be pretty
3304 * safe, since we just read an EOF from its stdout. We could try
3305 * to do better, by using wait(), and keeping track of background jobs
3306 * at the same time. That would be a lot of work, and contrary
3307 * to the KISS philosophy of this program. */
3308 retcode = fclose(p);
3309 free_pipe_list(inner.list_head, /* indent: */ 0);
3310 debug_printf("closed FILE from child, retcode=%d\n", retcode);
3315 static int parse_group(o_string *dest, struct p_context *ctx,
3316 struct in_str *input, int ch)
3319 const char *endch = NULL;
3320 struct p_context sub;
3321 struct child_prog *child = ctx->child;
3323 debug_printf_parse("parse_group entered\n");
3326 debug_printf_parse("parse_group return 1: syntax error, groups and arglists don't mix\n");
3329 initialize_context(&sub);
3333 child->subshell = 1;
3335 rcode = parse_stream(dest, &sub, input, endch);
3337 done_word(dest, &sub); /* finish off the final word in the subcontext */
3338 done_pipe(&sub, PIPE_SEQ); /* and the final command there, too */
3339 child->group = sub.list_head;
3341 debug_printf_parse("parse_group return %d\n", rcode);
3343 /* child remains "open", available for possible redirects */
3346 /* Basically useful version until someone wants to get fancier,
3347 * see the bash man page under "Parameter Expansion" */
3348 static const char *lookup_param(const char *src)
3350 struct variable *var = get_local_var(src);
3352 return strchr(var->varstr, '=') + 1;
3356 /* return code: 0 for OK, 1 for syntax error */
3357 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input)
3359 int ch = b_peek(input); /* first character after the $ */
3360 unsigned char quote_mask = dest->o_quote ? 0x80 : 0;
3362 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
3364 b_addchr(dest, SPECIAL_VAR_SYMBOL);
3365 //sp: ctx->child->sp++;
3367 debug_printf_parse(": '%c'\n", ch);
3369 b_addchr(dest, ch | quote_mask);
3372 if (!isalnum(ch) && ch != '_')
3375 b_addchr(dest, SPECIAL_VAR_SYMBOL);
3376 } else if (isdigit(ch)) {
3378 b_addchr(dest, SPECIAL_VAR_SYMBOL);
3379 //sp: ctx->child->sp++;
3380 debug_printf_parse(": '%c'\n", ch);
3382 b_addchr(dest, ch | quote_mask);
3383 b_addchr(dest, SPECIAL_VAR_SYMBOL);
3384 } else switch (ch) {
3386 case '!': /* last bg pid */
3387 case '?': /* last exit code */
3388 case '#': /* number of args */
3389 case '*': /* args */
3390 case '@': /* args */
3391 goto make_one_char_var;
3393 b_addchr(dest, SPECIAL_VAR_SYMBOL);
3394 //sp: ctx->child->sp++;
3396 /* XXX maybe someone will try to escape the '}' */
3398 ch = b_getch(input);
3401 if (!isalnum(ch) && ch != '_') {
3402 syntax("unterminated ${name}");
3403 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
3406 debug_printf_parse(": '%c'\n", ch);
3407 b_addchr(dest, ch | quote_mask);
3410 b_addchr(dest, SPECIAL_VAR_SYMBOL);
3412 #if ENABLE_HUSH_TICK
3415 process_command_subs(dest, ctx, input, ")");
3420 /* still unhandled, but should be eventually */
3421 bb_error_msg("unhandled syntax: $%c", ch);
3425 b_addqchr(dest, '$', dest->o_quote);
3427 debug_printf_parse("handle_dollar return 0\n");
3431 /* return code is 0 for normal exit, 1 for syntax error */
3432 static int parse_stream(o_string *dest, struct p_context *ctx,
3433 struct in_str *input, const char *end_trigger)
3437 redir_type redir_style;
3440 /* Only double-quote state is handled in the state variable dest->o_quote.
3441 * A single-quote triggers a bypass of the main loop until its mate is
3442 * found. When recursing, quote state is passed in via dest->o_quote. */
3444 debug_printf_parse("parse_stream entered, end_trigger='%s'\n", end_trigger);
3449 ch = b_getch(input);
3453 next = b_peek(input);
3455 debug_printf_parse(": ch=%c (%d) m=%d quote=%d\n",
3456 ch, ch, m, dest->o_quote);
3457 if (m == CHAR_ORDINARY
3458 || (m != CHAR_SPECIAL && dest->o_quote)
3461 syntax("unterminated \"");
3462 debug_printf_parse("parse_stream return 1: unterminated \"\n");
3465 b_addqchr(dest, ch, dest->o_quote);
3468 if (m == CHAR_IFS) {
3469 if (done_word(dest, ctx)) {
3470 debug_printf_parse("parse_stream return 1: done_word!=0\n");
3475 /* If we aren't performing a substitution, treat
3476 * a newline as a command separator.
3477 * [why we don't handle it exactly like ';'? --vda] */
3478 if (end_trigger && ch == '\n') {
3479 done_pipe(ctx, PIPE_SEQ);
3482 if ((end_trigger && strchr(end_trigger, ch))
3483 && !dest->o_quote && ctx->res_w == RES_NONE
3485 debug_printf_parse("parse_stream return 0: end_trigger char found\n");
3492 if (dest->length == 0 && !dest->o_quote) {
3495 if (ch == EOF || ch == '\n')
3500 b_addqchr(dest, ch, dest->o_quote);
3506 debug_printf_parse("parse_stream return 1: \\<eof>\n");
3509 b_addqchr(dest, '\\', dest->o_quote);
3510 b_addqchr(dest, b_getch(input), dest->o_quote);
3513 if (handle_dollar(dest, ctx, input) != 0) {
3514 debug_printf_parse("parse_stream return 1: handle_dollar returned non-0\n");
3521 ch = b_getch(input);
3522 if (ch == EOF || ch == '\'')
3527 syntax("unterminated '");
3528 debug_printf_parse("parse_stream return 1: unterminated '\n");
3534 dest->o_quote ^= 1; /* invert */
3536 #if ENABLE_HUSH_TICK
3538 process_command_subs(dest, ctx, input, "`");
3542 redir_fd = redirect_opt_num(dest);
3543 done_word(dest, ctx);
3544 redir_style = REDIRECT_OVERWRITE;
3546 redir_style = REDIRECT_APPEND;
3550 else if (next == '(') {
3551 syntax(">(process) not supported");
3552 debug_printf_parse("parse_stream return 1: >(process) not supported\n");
3556 setup_redirect(ctx, redir_fd, redir_style, input);
3559 redir_fd = redirect_opt_num(dest);
3560 done_word(dest, ctx);
3561 redir_style = REDIRECT_INPUT;
3563 redir_style = REDIRECT_HEREIS;
3565 } else if (next == '>') {
3566 redir_style = REDIRECT_IO;
3570 else if (next == '(') {
3571 syntax("<(process) not supported");
3572 debug_printf_parse("parse_stream return 1: <(process) not supported\n");
3576 setup_redirect(ctx, redir_fd, redir_style, input);
3579 done_word(dest, ctx);
3580 done_pipe(ctx, PIPE_SEQ);
3583 done_word(dest, ctx);
3586 done_pipe(ctx, PIPE_AND);
3588 done_pipe(ctx, PIPE_BG);
3592 done_word(dest, ctx);
3595 done_pipe(ctx, PIPE_OR);
3597 /* we could pick up a file descriptor choice here
3598 * with redirect_opt_num(), but bash doesn't do it.
3599 * "echo foo 2| cat" yields "foo 2". */
3605 if (parse_group(dest, ctx, input, ch) != 0) {
3606 debug_printf_parse("parse_stream return 1: parse_group returned non-0\n");
3612 syntax("unexpected }"); /* Proper use of this character is caught by end_trigger */
3613 debug_printf_parse("parse_stream return 1: unexpected '}'\n");
3616 if (ENABLE_HUSH_DEBUG)
3617 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
3620 /* Complain if quote? No, maybe we just finished a command substitution
3621 * that was quoted. Example:
3622 * $ echo "`cat foo` plus more"
3623 * and we just got the EOF generated by the subshell that ran "cat foo"
3624 * The only real complaint is if we got an EOF when end_trigger != NULL,
3625 * that is, we were really supposed to get end_trigger, and never got
3626 * one before the EOF. Can't use the standard "syntax error" return code,
3627 * so that parse_stream_outer can distinguish the EOF and exit smoothly. */
3628 debug_printf_parse("parse_stream return %d\n", -(end_trigger != NULL));
3634 static void set_in_charmap(const char *set, int code)
3637 charmap[(unsigned char)*set++] = code;
3640 static void update_charmap(void)
3642 /* char *ifs and char charmap[256] are both globals. */
3643 ifs = getenv("IFS");
3646 /* Precompute a list of 'flow through' behavior so it can be treated
3647 * quickly up front. Computation is necessary because of IFS.
3648 * Special case handling of IFS == " \t\n" is not implemented.
3649 * The charmap[] array only really needs two bits each,
3650 * and on most machines that would be faster (reduced L1 cache use).
3652 memset(charmap, CHAR_ORDINARY, sizeof(charmap));
3653 #if ENABLE_HUSH_TICK
3654 set_in_charmap("\\$\"`", CHAR_SPECIAL);
3656 set_in_charmap("\\$\"", CHAR_SPECIAL);
3658 set_in_charmap("<>;&|(){}#'", CHAR_ORDINARY_IF_QUOTED);
3659 set_in_charmap(ifs, CHAR_IFS); /* are ordinary if quoted */
3662 /* most recursion does not come through here, the exception is
3663 * from builtin_source() and builtin_eval() */
3664 static int parse_and_run_stream(struct in_str *inp, int parse_flag)
3666 struct p_context ctx;
3667 o_string temp = NULL_O_STRING;
3670 ctx.parse_type = parse_flag;
3671 initialize_context(&ctx);
3673 if (!(parse_flag & PARSEFLAG_SEMICOLON) || (parse_flag & PARSEFLAG_REPARSING))
3674 set_in_charmap(";$&|", CHAR_ORDINARY);
3675 #if ENABLE_HUSH_INTERACTIVE
3676 inp->promptmode = 0; /* PS1 */
3678 /* We will stop & execute after each ';' or '\n'.
3679 * Example: "sleep 9999; echo TEST" + ctrl-C:
3680 * TEST should be printed */
3681 rcode = parse_stream(&temp, &ctx, inp, ";\n");
3682 if (rcode != 1 && ctx.old_flag != 0) {
3685 if (rcode != 1 && ctx.old_flag == 0) {
3686 done_word(&temp, &ctx);
3687 done_pipe(&ctx, PIPE_SEQ);
3688 debug_print_tree(ctx.list_head, 0);
3689 debug_printf_exec("parse_stream_outer: run_and_free_list\n");
3690 run_and_free_list(ctx.list_head);
3692 if (ctx.old_flag != 0) {
3699 free_pipe_list(ctx.list_head, /* indent: */ 0);
3702 } while (rcode != -1 && !(parse_flag & PARSEFLAG_EXIT_FROM_LOOP)); /* loop on syntax errors, return on EOF */
3706 static int parse_and_run_string(const char *s, int parse_flag)
3708 struct in_str input;
3709 setup_string_in_str(&input, s);
3710 return parse_and_run_stream(&input, parse_flag);
3713 static int parse_and_run_file(FILE *f)
3716 struct in_str input;
3717 setup_file_in_str(&input, f);
3718 rcode = parse_and_run_stream(&input, PARSEFLAG_SEMICOLON);
3723 /* Make sure we have a controlling tty. If we get started under a job
3724 * aware app (like bash for example), make sure we are now in charge so
3725 * we don't fight over who gets the foreground */
3726 static void setup_job_control(void)
3730 saved_task_pgrp = shell_pgrp = getpgrp();
3731 debug_printf_jobs("saved_task_pgrp=%d\n", saved_task_pgrp);
3732 close_on_exec_on(interactive_fd);
3734 /* If we were ran as 'hush &',
3735 * sleep until we are in the foreground. */
3736 while (tcgetpgrp(interactive_fd) != shell_pgrp) {
3737 /* Send TTIN to ourself (should stop us) */
3738 kill(- shell_pgrp, SIGTTIN);
3739 shell_pgrp = getpgrp();
3742 /* Ignore job-control and misc signals. */
3743 set_jobctrl_sighandler(SIG_IGN);
3744 set_misc_sighandler(SIG_IGN);
3745 //huh? signal(SIGCHLD, SIG_IGN);
3747 /* We _must_ restore tty pgrp on fatal signals */
3748 set_fatal_sighandler(sigexit);
3750 /* Put ourselves in our own process group. */
3751 setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
3752 /* Grab control of the terminal. */
3753 tcsetpgrp(interactive_fd, getpid());
3757 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
3758 int hush_main(int argc, char **argv)
3760 static const char version_str[] ALIGN1 = "HUSH_VERSION="HUSH_VER_STR;
3761 static const struct variable const_shell_ver = {
3763 .varstr = (char*)version_str,
3764 .max_len = 1, /* 0 can provoke free(name) */
3772 struct variable *cur_var;
3776 /* Deal with HUSH_VERSION */
3777 shell_ver = const_shell_ver; /* copying struct here */
3778 top_var = &shell_ver;
3779 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
3780 /* Initialize our shell local variables with the values
3781 * currently living in the environment */
3785 char *value = strchr(*e, '=');
3786 if (value) { /* paranoia */
3787 cur_var->next = xzalloc(sizeof(*cur_var));
3788 cur_var = cur_var->next;
3789 cur_var->varstr = *e;
3790 cur_var->max_len = strlen(*e);
3791 cur_var->flg_export = 1;
3795 putenv((char *)version_str); /* reinstate HUSH_VERSION */
3797 #if ENABLE_FEATURE_EDITING
3798 line_input_state = new_line_input_t(FOR_SHELL);
3800 /* XXX what should these be while sourcing /etc/profile? */
3803 /* Initialize some more globals to non-zero values */
3805 #if ENABLE_HUSH_INTERACTIVE
3806 #if ENABLE_FEATURE_EDITING
3807 cmdedit_set_initial_prompt();
3812 if (EXIT_SUCCESS) /* otherwise is already done */
3813 last_return_code = EXIT_SUCCESS;
3815 if (argv[0] && argv[0][0] == '-') {
3816 debug_printf("sourcing /etc/profile\n");
3817 input = fopen("/etc/profile", "r");
3818 if (input != NULL) {
3819 close_on_exec_on(fileno(input));
3820 parse_and_run_file(input);
3826 while ((opt = getopt(argc, argv, "c:xif")) > 0) {
3829 global_argv = argv + optind;
3830 global_argc = argc - optind;
3831 opt = parse_and_run_string(optarg, PARSEFLAG_SEMICOLON);
3834 /* Well, we cannot just declare interactiveness,
3835 * we have to have some stuff (ctty, etc) */
3836 /* interactive_fd++; */
3843 fprintf(stderr, "Usage: sh [FILE]...\n"
3844 " or: sh -c command [args]...\n\n");
3852 /* A shell is interactive if the '-i' flag was given, or if all of
3853 * the following conditions are met:
3855 * no arguments remaining or the -s flag given
3856 * standard input is a terminal
3857 * standard output is a terminal
3858 * Refer to Posix.2, the description of the 'sh' utility. */
3859 if (argv[optind] == NULL && input == stdin
3860 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
3862 saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
3863 debug_printf("saved_tty_pgrp=%d\n", saved_tty_pgrp);
3864 if (saved_tty_pgrp >= 0) {
3865 /* try to dup to high fd#, >= 255 */
3866 interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
3867 if (interactive_fd < 0) {
3868 /* try to dup to any fd */
3869 interactive_fd = dup(STDIN_FILENO);
3870 if (interactive_fd < 0)
3874 // TODO: track & disallow any attempts of user
3875 // to (inadvertently) close/redirect it
3878 debug_printf("interactive_fd=%d\n", interactive_fd);
3879 if (interactive_fd) {
3880 fcntl(interactive_fd, F_SETFD, FD_CLOEXEC);
3881 /* Looks like they want an interactive shell */
3882 setup_job_control();
3883 /* -1 is special - makes xfuncs longjmp, not exit
3884 * (we reset die_sleep = 0 whereever we [v]fork) */
3886 if (setjmp(die_jmp)) {
3887 /* xfunc has failed! die die die */
3888 hush_exit(xfunc_error_retval);
3890 #if !ENABLE_FEATURE_SH_EXTRA_QUIET
3891 printf("\n\n%s hush - the humble shell v"HUSH_VER_STR"\n", bb_banner);
3892 printf("Enter 'help' for a list of built-in commands.\n\n");
3895 #elif ENABLE_HUSH_INTERACTIVE
3896 /* no job control compiled, only prompt/line editing */
3897 if (argv[optind] == NULL && input == stdin
3898 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
3900 interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
3901 if (interactive_fd < 0) {
3902 /* try to dup to any fd */
3903 interactive_fd = dup(STDIN_FILENO);
3904 if (interactive_fd < 0)
3909 fcntl(interactive_fd, F_SETFD, FD_CLOEXEC);
3913 if (argv[optind] == NULL) {
3914 opt = parse_and_run_file(stdin);
3916 debug_printf("\nrunning script '%s'\n", argv[optind]);
3917 global_argv = argv + optind;
3918 global_argc = argc - optind;
3919 input = xfopen(argv[optind], "r");
3920 fcntl(fileno(input), F_SETFD, FD_CLOEXEC);
3921 opt = parse_and_run_file(input);
3926 #if ENABLE_FEATURE_CLEAN_UP
3928 if (cwd != bb_msg_unknown)
3930 cur_var = top_var->next;
3932 struct variable *tmp = cur_var;
3933 if (!cur_var->max_len)
3934 free(cur_var->varstr);
3935 cur_var = cur_var->next;
3939 hush_exit(opt ? opt : last_return_code);
3944 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
3945 int lash_main(int argc, char **argv)
3947 //bb_error_msg("lash is deprecated, please use hush instead");
3948 return hush_main(argc, argv);