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,*/
540 struct in_str *input, const char *subst_end);
542 static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch);
543 static const char *lookup_param(const char *src);
544 static int handle_dollar(o_string *dest, /*struct p_context *ctx,*/
545 struct in_str *input);
546 static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, const char *end_trigger);
548 static int parse_and_run_stream(struct in_str *inp, int parse_flag);
549 static int parse_and_run_string(const char *s, int parse_flag);
550 static int parse_and_run_file(FILE *f);
551 /* job management: */
552 static int checkjobs(struct pipe* fg_pipe);
554 static int checkjobs_and_fg_shell(struct pipe* fg_pipe);
555 static void insert_bg_job(struct pipe *pi);
556 static void remove_bg_job(struct pipe *pi);
557 static void delete_finished_bg_job(struct pipe *pi);
559 int checkjobs_and_fg_shell(struct pipe* fg_pipe); /* never called */
561 /* local variable support */
562 static char **expand_strvec_to_strvec(char **argv);
564 static char *expand_strvec_to_string(char **argv);
565 /* used for expansion of right hand of assignments */
566 static char *expand_string_to_string(const char *str);
567 static struct variable *get_local_var(const char *name);
568 static int set_local_var(char *str, int flg_export);
569 static void unset_local_var(const char *name);
572 static char **add_strings_to_strings(int need_xstrdup, char **strings, char **add)
593 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
594 v[count1 + count2] = NULL;
597 v[count1 + i] = need_xstrdup ? xstrdup(add[i]) : add[i];
601 /* 'add' should be a malloced pointer */
602 static char **add_string_to_strings(char **strings, char *add)
609 return add_strings_to_strings(0, strings, v);
612 static void free_strings(char **strings)
623 /* Function prototypes for builtins */
624 static int builtin_cd(char **argv);
625 static int builtin_echo(char **argv);
626 static int builtin_eval(char **argv);
627 static int builtin_exec(char **argv);
628 static int builtin_exit(char **argv);
629 static int builtin_export(char **argv);
631 static int builtin_fg_bg(char **argv);
632 static int builtin_jobs(char **argv);
635 static int builtin_help(char **argv);
637 static int builtin_pwd(char **argv);
638 static int builtin_read(char **argv);
639 static int builtin_test(char **argv);
640 static int builtin_set(char **argv);
641 static int builtin_shift(char **argv);
642 static int builtin_source(char **argv);
643 static int builtin_umask(char **argv);
644 static int builtin_unset(char **argv);
645 //static int builtin_not_written(char **argv);
647 /* Table of built-in functions. They can be forked or not, depending on
648 * context: within pipes, they fork. As simple commands, they do not.
649 * When used in non-forking context, they can change global variables
650 * in the parent shell process. If forked, of course they cannot.
651 * For example, 'unset foo | whatever' will parse and run, but foo will
652 * still be set at the end. */
653 struct built_in_command {
654 const char *cmd; /* name */
655 int (*function) (char **argv); /* function ptr */
657 const char *descr; /* description */
658 #define BLTIN(cmd, func, help) { cmd, func, help }
660 #define BLTIN(cmd, func, help) { cmd, func }
664 /* For now, echo and test are unconditionally enabled.
665 * Maybe make it configurable? */
666 static const struct built_in_command bltins[] = {
667 BLTIN("[" , builtin_test, "Test condition"),
668 BLTIN("[[" , builtin_test, "Test condition"),
670 BLTIN("bg" , builtin_fg_bg, "Resume a job in the background"),
672 // BLTIN("break" , builtin_not_written, "Exit for, while or until loop"),
673 BLTIN("cd" , builtin_cd, "Change working directory"),
674 // BLTIN("continue", builtin_not_written, "Continue for, while or until loop"),
675 BLTIN("echo" , builtin_echo, "Write strings to stdout"),
676 BLTIN("eval" , builtin_eval, "Construct and run shell command"),
677 BLTIN("exec" , builtin_exec, "Exec command, replacing this shell with the exec'd process"),
678 BLTIN("exit" , builtin_exit, "Exit from shell"),
679 BLTIN("export", builtin_export, "Set environment variable"),
681 BLTIN("fg" , builtin_fg_bg, "Bring job into the foreground"),
682 BLTIN("jobs" , builtin_jobs, "Lists the active jobs"),
684 // TODO: remove pwd? we have it as an applet...
685 BLTIN("pwd" , builtin_pwd, "Print current directory"),
686 BLTIN("read" , builtin_read, "Input environment variable"),
687 // BLTIN("return", builtin_not_written, "Return from a function"),
688 BLTIN("set" , builtin_set, "Set/unset shell local variables"),
689 BLTIN("shift" , builtin_shift, "Shift positional parameters"),
690 // BLTIN("trap" , builtin_not_written, "Trap signals"),
691 BLTIN("test" , builtin_test, "Test condition"),
692 // BLTIN("ulimit", builtin_not_written, "Controls resource limits"),
693 BLTIN("umask" , builtin_umask, "Sets file creation mask"),
694 BLTIN("unset" , builtin_unset, "Unset environment variable"),
695 BLTIN("." , builtin_source, "Source-in and run commands in a file"),
697 BLTIN("help" , builtin_help, "List shell built-in commands"),
699 BLTIN(NULL, NULL, NULL)
704 /* Signals are grouped, we handle them in batches */
705 static void set_fatal_sighandler(void (*handler)(int))
714 /* bash 3.2 seems to handle these just like 'fatal' ones */
720 static void set_jobctrl_sighandler(void (*handler)(int))
728 static void set_misc_sighandler(void (*handler)(int))
736 /* SIGCHLD is special and handled separately */
738 static void set_every_sighandler(void (*handler)(int))
740 set_fatal_sighandler(handler);
741 set_jobctrl_sighandler(handler);
742 set_misc_sighandler(handler);
743 signal(SIGCHLD, handler);
746 static void handler_ctrl_c(int sig ATTRIBUTE_UNUSED)
748 debug_printf_jobs("got sig %d\n", sig);
749 // as usual we can have all kinds of nasty problems with leaked malloc data here
750 siglongjmp(toplevel_jb, 1);
753 static void handler_ctrl_z(int sig ATTRIBUTE_UNUSED)
757 debug_printf_jobs("got tty sig %d in pid %d\n", sig, getpid());
759 if (pid < 0) /* can't fork. Pretend there was no ctrl-Z */
762 if (!pid) { /* child */
764 die_sleep = 0; /* let nofork's xfuncs die */
766 debug_printf_jobs("set pgrp for child %d ok\n", getpid());
767 set_every_sighandler(SIG_DFL);
768 raise(SIGTSTP); /* resend TSTP so that child will be stopped */
769 debug_printf_jobs("returning in child\n");
770 /* return to nofork, it will eventually exit now,
771 * not return back to shell */
775 /* finish filling up pipe info */
776 toplevel_list->pgrp = pid; /* child is in its own pgrp */
777 toplevel_list->progs[0].pid = pid;
778 /* parent needs to longjmp out of running nofork.
779 * we will "return" exitcode 0, with child put in background */
780 // as usual we can have all kinds of nasty problems with leaked malloc data here
781 debug_printf_jobs("siglongjmp in parent\n");
782 siglongjmp(toplevel_jb, 1);
785 /* Restores tty foreground process group, and exits.
786 * May be called as signal handler for fatal signal
787 * (will faithfully resend signal to itself, producing correct exit state)
788 * or called directly with -EXITCODE.
789 * We also call it if xfunc is exiting. */
790 static void sigexit(int sig) ATTRIBUTE_NORETURN;
791 static void sigexit(int sig)
793 /* Disable all signals: job control, SIGPIPE, etc. */
794 sigprocmask_allsigs(SIG_BLOCK);
797 tcsetpgrp(interactive_fd, saved_tty_pgrp);
799 /* Not a signal, just exit */
803 kill_myself_with_sig(sig); /* does not return */
806 /* Restores tty foreground process group, and exits. */
807 static void hush_exit(int exitcode) ATTRIBUTE_NORETURN;
808 static void hush_exit(int exitcode)
810 fflush(NULL); /* flush all streams */
811 sigexit(- (exitcode & 0xff));
816 #define set_fatal_sighandler(handler) ((void)0)
817 #define set_jobctrl_sighandler(handler) ((void)0)
818 #define set_misc_sighandler(handler) ((void)0)
819 #define hush_exit(e) exit(e)
824 static const char *set_cwd(void)
826 if (cwd == bb_msg_unknown)
827 cwd = NULL; /* xrealloc_getcwd_or_warn(arg) calls free(arg)! */
828 cwd = xrealloc_getcwd_or_warn((char *)cwd);
830 cwd = bb_msg_unknown;
835 /* built-in 'test' handler */
836 static int builtin_test(char **argv)
843 return test_main(argc, argv - argc);
846 /* built-in 'test' handler */
847 static int builtin_echo(char **argv)
854 return echo_main(argc, argv - argc);
857 /* built-in 'eval' handler */
858 static int builtin_eval(char **argv)
860 int rcode = EXIT_SUCCESS;
863 char *str = expand_strvec_to_string(argv + 1);
864 parse_and_run_string(str, PARSEFLAG_EXIT_FROM_LOOP |
865 PARSEFLAG_SEMICOLON);
867 rcode = last_return_code;
872 /* built-in 'cd <path>' handler */
873 static int builtin_cd(char **argv)
876 if (argv[1] == NULL) {
877 // bash does nothing (exitcode 0) if HOME is ""; if it's unset,
878 // bash says "bash: cd: HOME not set" and does nothing (exitcode 1)
879 newdir = getenv("HOME") ? : "/";
883 printf("cd: %s: %s\n", newdir, strerror(errno));
890 /* built-in 'exec' handler */
891 static int builtin_exec(char **argv)
894 return EXIT_SUCCESS; /* Really? */
895 pseudo_exec_argv(argv + 1);
899 /* built-in 'exit' handler */
900 static int builtin_exit(char **argv)
902 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
903 //puts("exit"); /* bash does it */
904 // TODO: warn if we have background jobs: "There are stopped jobs"
905 // On second consecutive 'exit', exit anyway.
908 hush_exit(last_return_code);
909 /* mimic bash: exit 123abc == exit 255 + error msg */
910 xfunc_error_retval = 255;
911 /* bash: exit -2 == exit 254, no error msg */
912 hush_exit(xatoi(argv[1]) & 0xff);
915 /* built-in 'export VAR=value' handler */
916 static int builtin_export(char **argv)
919 char *name = argv[1];
923 // ash emits: export VAR='VAL'
924 // bash: declare -x VAR="VAL"
925 // (both also escape as needed (quotes, $, etc))
933 value = strchr(name, '=');
935 /* They are exporting something without a =VALUE */
936 struct variable *var;
938 var = get_local_var(name);
943 /* bash does not return an error when trying to export
944 * an undefined variable. Do likewise. */
948 set_local_var(xstrdup(name), 1);
953 /* built-in 'fg' and 'bg' handler */
954 static int builtin_fg_bg(char **argv)
961 /* If they gave us no args, assume they want the last backgrounded task */
963 for (pi = job_list; pi; pi = pi->next) {
964 if (pi->jobid == last_jobid) {
968 bb_error_msg("%s: no current job", argv[0]);
971 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
972 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
975 for (pi = job_list; pi; pi = pi->next) {
976 if (pi->jobid == jobnum) {
980 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
983 // TODO: bash prints a string representation
984 // of job being foregrounded (like "sleep 1 | cat")
985 if (*argv[0] == 'f') {
986 /* Put the job into the foreground. */
987 tcsetpgrp(interactive_fd, pi->pgrp);
990 /* Restart the processes in the job */
991 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_progs, pi->pgrp);
992 for (i = 0; i < pi->num_progs; i++) {
993 debug_printf_jobs("reviving pid %d\n", pi->progs[i].pid);
994 pi->progs[i].is_stopped = 0;
996 pi->stopped_progs = 0;
998 i = kill(- pi->pgrp, SIGCONT);
1000 if (errno == ESRCH) {
1001 delete_finished_bg_job(pi);
1002 return EXIT_SUCCESS;
1004 bb_perror_msg("kill (SIGCONT)");
1008 if (*argv[0] == 'f') {
1010 return checkjobs_and_fg_shell(pi);
1012 return EXIT_SUCCESS;
1016 /* built-in 'help' handler */
1017 #if ENABLE_HUSH_HELP
1018 static int builtin_help(char **argv ATTRIBUTE_UNUSED)
1020 const struct built_in_command *x;
1022 printf("\nBuilt-in commands:\n");
1023 printf("-------------------\n");
1024 for (x = bltins; x->cmd; x++) {
1025 printf("%s\t%s\n", x->cmd, x->descr);
1028 return EXIT_SUCCESS;
1033 /* built-in 'jobs' handler */
1034 static int builtin_jobs(char **argv ATTRIBUTE_UNUSED)
1037 const char *status_string;
1039 for (job = job_list; job; job = job->next) {
1040 if (job->running_progs == job->stopped_progs)
1041 status_string = "Stopped";
1043 status_string = "Running";
1045 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
1047 return EXIT_SUCCESS;
1051 /* built-in 'pwd' handler */
1052 static int builtin_pwd(char **argv ATTRIBUTE_UNUSED)
1055 return EXIT_SUCCESS;
1058 /* built-in 'read VAR' handler */
1059 static int builtin_read(char **argv)
1062 const char *name = argv[1] ? argv[1] : "REPLY";
1064 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name));
1065 return set_local_var(string, 0);
1068 /* built-in 'set [VAR=value]' handler */
1069 static int builtin_set(char **argv)
1071 char *temp = argv[1];
1075 for (e = top_var; e; e = e->next)
1078 set_local_var(xstrdup(temp), 0);
1080 return EXIT_SUCCESS;
1084 /* Built-in 'shift' handler */
1085 static int builtin_shift(char **argv)
1091 if (n >= 0 && n < global_argc) {
1092 global_argv[n] = global_argv[0];
1095 return EXIT_SUCCESS;
1097 return EXIT_FAILURE;
1100 /* Built-in '.' handler (read-in and execute commands from file) */
1101 static int builtin_source(char **argv)
1106 if (argv[1] == NULL)
1107 return EXIT_FAILURE;
1109 /* XXX search through $PATH is missing */
1110 input = fopen(argv[1], "r");
1112 bb_error_msg("cannot open '%s'", argv[1]);
1113 return EXIT_FAILURE;
1115 close_on_exec_on(fileno(input));
1117 /* Now run the file */
1118 /* XXX argv and argc are broken; need to save old global_argv
1119 * (pointer only is OK!) on this stack frame,
1120 * set global_argv=argv+1, recurse, and restore. */
1121 status = parse_and_run_file(input);
1126 static int builtin_umask(char **argv)
1129 const char *arg = argv[1];
1132 new_umask = strtoul(arg, &end, 8);
1133 if (*end != '\0' || end == arg) {
1134 return EXIT_FAILURE;
1137 new_umask = umask(0);
1138 printf("%.3o\n", (unsigned) new_umask);
1141 return EXIT_SUCCESS;
1144 /* built-in 'unset VAR' handler */
1145 static int builtin_unset(char **argv)
1147 /* bash always returns true */
1148 unset_local_var(argv[1]);
1149 return EXIT_SUCCESS;
1152 //static int builtin_not_written(char **argv)
1154 // printf("builtin_%s not written\n", argv[0]);
1155 // return EXIT_FAILURE;
1158 static int b_check_space(o_string *o, int len)
1160 /* It would be easy to drop a more restrictive policy
1161 * in here, such as setting a maximum string length */
1162 if (o->length + len > o->maxlen) {
1163 /* assert(data == NULL || o->maxlen != 0); */
1164 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1165 o->data = xrealloc(o->data, 1 + o->maxlen);
1167 return o->data == NULL;
1170 static int b_addchr(o_string *o, int ch)
1172 debug_printf("b_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1173 if (b_check_space(o, 1))
1175 o->data[o->length] = ch;
1177 o->data[o->length] = '\0';
1181 static void b_reset(o_string *o)
1189 static void b_free(o_string *o)
1192 memset(o, 0, sizeof(*o));
1195 /* My analysis of quoting semantics tells me that state information
1196 * is associated with a destination, not a source.
1198 static int b_addqchr(o_string *o, int ch, int quote)
1200 if (quote && strchr("*?[\\", ch)) {
1202 rc = b_addchr(o, '\\');
1206 return b_addchr(o, ch);
1209 static int static_get(struct in_str *i)
1212 if (ch == '\0') return EOF;
1216 static int static_peek(struct in_str *i)
1221 #if ENABLE_HUSH_INTERACTIVE
1222 #if ENABLE_FEATURE_EDITING
1223 static void cmdedit_set_initial_prompt(void)
1225 #if !ENABLE_FEATURE_EDITING_FANCY_PROMPT
1228 PS1 = getenv("PS1");
1233 #endif /* EDITING */
1235 static const char* setup_prompt_string(int promptmode)
1237 const char *prompt_str;
1238 debug_printf("setup_prompt_string %d ", promptmode);
1239 #if !ENABLE_FEATURE_EDITING_FANCY_PROMPT
1240 /* Set up the prompt */
1241 if (promptmode == 0) { /* PS1 */
1243 PS1 = xasprintf("%s %c ", cwd, (geteuid() != 0) ? '$' : '#');
1249 prompt_str = (promptmode == 0) ? PS1 : PS2;
1251 debug_printf("result '%s'\n", prompt_str);
1255 static void get_user_input(struct in_str *i)
1258 const char *prompt_str;
1260 prompt_str = setup_prompt_string(i->promptmode);
1261 #if ENABLE_FEATURE_EDITING
1262 /* Enable command line editing only while a command line
1263 * is actually being read */
1265 r = read_line_input(prompt_str, user_input_buf, BUFSIZ-1, line_input_state);
1266 } while (r == 0); /* repeat if Ctrl-C */
1267 i->eof_flag = (r < 0);
1268 if (i->eof_flag) { /* EOF/error detected */
1269 user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1270 user_input_buf[1] = '\0';
1273 fputs(prompt_str, stdout);
1275 user_input_buf[0] = r = fgetc(i->file);
1276 /*user_input_buf[1] = '\0'; - already is and never changed */
1277 i->eof_flag = (r == EOF);
1279 i->p = user_input_buf;
1281 #endif /* INTERACTIVE */
1283 /* This is the magic location that prints prompts
1284 * and gets data back from the user */
1285 static int file_get(struct in_str *i)
1289 /* If there is data waiting, eat it up */
1290 if (i->p && *i->p) {
1291 #if ENABLE_HUSH_INTERACTIVE
1295 if (i->eof_flag && !*i->p)
1298 /* need to double check i->file because we might be doing something
1299 * more complicated by now, like sourcing or substituting. */
1300 #if ENABLE_HUSH_INTERACTIVE
1301 if (interactive_fd && i->promptme && i->file == stdin) {
1304 } while (!*i->p); /* need non-empty line */
1305 i->promptmode = 1; /* PS2 */
1310 ch = fgetc(i->file);
1312 debug_printf("file_get: got a '%c' %d\n", ch, ch);
1313 #if ENABLE_HUSH_INTERACTIVE
1320 /* All the callers guarantee this routine will never be
1321 * used right after a newline, so prompting is not needed.
1323 static int file_peek(struct in_str *i)
1326 if (i->p && *i->p) {
1327 if (i->eof_flag && !i->p[1])
1331 ch = fgetc(i->file);
1332 i->eof_flag = (ch == EOF);
1333 i->peek_buf[0] = ch;
1334 i->peek_buf[1] = '\0';
1336 debug_printf("file_peek: got a '%c' %d\n", *i->p, *i->p);
1340 static void setup_file_in_str(struct in_str *i, FILE *f)
1342 i->peek = file_peek;
1344 #if ENABLE_HUSH_INTERACTIVE
1346 i->promptmode = 0; /* PS1 */
1352 static void setup_string_in_str(struct in_str *i, const char *s)
1354 i->peek = static_peek;
1355 i->get = static_get;
1356 #if ENABLE_HUSH_INTERACTIVE
1358 i->promptmode = 0; /* PS1 */
1364 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
1365 * and stderr if they are redirected. */
1366 static int setup_redirects(struct child_prog *prog, int squirrel[])
1369 struct redir_struct *redir;
1371 for (redir = prog->redirects; redir; redir = redir->next) {
1372 if (redir->dup == -1 && redir->glob_word == NULL) {
1373 /* something went wrong in the parse. Pretend it didn't happen */
1376 if (redir->dup == -1) {
1378 mode = redir_table[redir->type].mode;
1379 p = expand_string_to_string(redir->glob_word[0]);
1380 openfd = open_or_warn(p, mode);
1383 /* this could get lost if stderr has been redirected, but
1384 bash and ash both lose it as well (though zsh doesn't!) */
1388 openfd = redir->dup;
1391 if (openfd != redir->fd) {
1392 if (squirrel && redir->fd < 3) {
1393 squirrel[redir->fd] = dup(redir->fd);
1396 //close(openfd); // close(-3) ??!
1398 dup2(openfd, redir->fd);
1399 if (redir->dup == -1)
1407 static void restore_redirects(int squirrel[])
1410 for (i = 0; i < 3; i++) {
1413 /* We simply die on error */
1419 /* Called after [v]fork() in run_pipe(), or from builtin_exec().
1421 * XXX no exit() here. If you don't exec, use _exit instead.
1422 * The at_exit handlers apparently confuse the calling process,
1423 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
1424 static void pseudo_exec_argv(char **argv)
1428 const struct built_in_command *x;
1430 for (i = 0; is_assignment(argv[i]); i++) {
1431 debug_printf_exec("pid %d environment modification: %s\n",
1433 // FIXME: vfork case??
1434 p = expand_string_to_string(argv[i]);
1438 /* If a variable is assigned in a forest, and nobody listens,
1439 * was it ever really set?
1442 _exit(EXIT_SUCCESS);
1444 argv = expand_strvec_to_strvec(argv);
1447 * Check if the command matches any of the builtins.
1448 * Depending on context, this might be redundant. But it's
1449 * easier to waste a few CPU cycles than it is to figure out
1450 * if this is one of those cases.
1452 for (x = bltins; x->cmd; x++) {
1453 if (strcmp(argv[0], x->cmd) == 0) {
1454 debug_printf_exec("running builtin '%s'\n", argv[0]);
1455 rcode = x->function(argv);
1461 /* Check if the command matches any busybox applets */
1462 #if ENABLE_FEATURE_SH_STANDALONE
1463 if (strchr(argv[0], '/') == NULL) {
1464 int a = find_applet_by_name(argv[0]);
1466 if (APPLET_IS_NOEXEC(a)) {
1467 debug_printf_exec("running applet '%s'\n", argv[0]);
1468 // is it ok that run_applet_no_and_exit() does exit(), not _exit()?
1469 run_applet_no_and_exit(a, argv);
1471 /* re-exec ourselves with the new arguments */
1472 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
1473 execvp(bb_busybox_exec_path, argv);
1474 /* If they called chroot or otherwise made the binary no longer
1475 * executable, fall through */
1480 debug_printf_exec("execing '%s'\n", argv[0]);
1481 execvp(argv[0], argv);
1482 bb_perror_msg("cannot exec '%s'", argv[0]);
1486 /* Called after [v]fork() in run_pipe()
1488 static void pseudo_exec(struct child_prog *child)
1490 // FIXME: buggy wrt NOMMU! Must not modify any global data
1491 // until it does exec/_exit, but currently it does
1492 // (puts malloc'ed stuff into environment)
1494 pseudo_exec_argv(child->argv);
1498 bb_error_msg_and_die("nested lists are not supported on NOMMU");
1502 #if ENABLE_HUSH_INTERACTIVE
1503 // run_list_level now takes care of it?
1504 // debug_printf_exec("pseudo_exec: setting interactive_fd=0\n");
1505 // interactive_fd = 0; /* crucial!!!! */
1507 debug_printf_exec("pseudo_exec: run_list\n");
1508 rcode = run_list(child->group);
1509 /* OK to leak memory by not calling free_pipe_list,
1510 * since this process is about to exit */
1515 /* Can happen. See what bash does with ">foo" by itself. */
1516 debug_printf("trying to pseudo_exec null command\n");
1517 _exit(EXIT_SUCCESS);
1521 static const char *get_cmdtext(struct pipe *pi)
1527 /* This is subtle. ->cmdtext is created only on first backgrounding.
1528 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
1529 * On subsequent bg argv is trashed, but we won't use it */
1532 argv = pi->progs[0].argv;
1533 if (!argv || !argv[0])
1534 return (pi->cmdtext = xzalloc(1));
1537 do len += strlen(*argv) + 1; while (*++argv);
1538 pi->cmdtext = p = xmalloc(len);
1539 argv = pi->progs[0].argv;
1541 len = strlen(*argv);
1542 memcpy(p, *argv, len);
1550 static void insert_bg_job(struct pipe *pi)
1552 struct pipe *thejob;
1555 /* Linear search for the ID of the job to use */
1557 for (thejob = job_list; thejob; thejob = thejob->next)
1558 if (thejob->jobid >= pi->jobid)
1559 pi->jobid = thejob->jobid + 1;
1561 /* Add thejob to the list of running jobs */
1563 thejob = job_list = xmalloc(sizeof(*thejob));
1565 for (thejob = job_list; thejob->next; thejob = thejob->next)
1567 thejob->next = xmalloc(sizeof(*thejob));
1568 thejob = thejob->next;
1571 /* Physically copy the struct job */
1572 memcpy(thejob, pi, sizeof(struct pipe));
1573 thejob->progs = xzalloc(sizeof(pi->progs[0]) * pi->num_progs);
1574 /* We cannot copy entire pi->progs[] vector! Double free()s will happen */
1575 for (i = 0; i < pi->num_progs; i++) {
1576 // TODO: do we really need to have so many fields which are just dead weight
1577 // at execution stage?
1578 thejob->progs[i].pid = pi->progs[i].pid;
1579 /* all other fields are not used and stay zero */
1581 thejob->next = NULL;
1582 thejob->cmdtext = xstrdup(get_cmdtext(pi));
1584 /* We don't wait for background thejobs to return -- append it
1585 to the list of backgrounded thejobs and leave it alone */
1586 printf("[%d] %d %s\n", thejob->jobid, thejob->progs[0].pid, thejob->cmdtext);
1587 last_bg_pid = thejob->progs[0].pid;
1588 last_jobid = thejob->jobid;
1591 static void remove_bg_job(struct pipe *pi)
1593 struct pipe *prev_pipe;
1595 if (pi == job_list) {
1596 job_list = pi->next;
1598 prev_pipe = job_list;
1599 while (prev_pipe->next != pi)
1600 prev_pipe = prev_pipe->next;
1601 prev_pipe->next = pi->next;
1604 last_jobid = job_list->jobid;
1609 /* remove a backgrounded job */
1610 static void delete_finished_bg_job(struct pipe *pi)
1613 pi->stopped_progs = 0;
1619 /* Checks to see if any processes have exited -- if they
1620 have, figure out why and see if a job has completed */
1621 static int checkjobs(struct pipe* fg_pipe)
1632 attributes = WUNTRACED;
1633 if (fg_pipe == NULL) {
1634 attributes |= WNOHANG;
1637 /* Do we do this right?
1638 * bash-3.00# sleep 20 | false
1640 * [3]+ Stopped sleep 20 | false
1641 * bash-3.00# echo $?
1642 * 1 <========== bg pipe is not fully done, but exitcode is already known!
1645 //FIXME: non-interactive bash does not continue even if all processes in fg pipe
1646 //are stopped. Testcase: "cat | cat" in a script (not on command line)
1647 // + killall -STOP cat
1650 // TODO: safe_waitpid?
1651 while ((childpid = waitpid(-1, &status, attributes)) > 0) {
1652 const int dead = WIFEXITED(status) || WIFSIGNALED(status);
1654 #ifdef DEBUG_SHELL_JOBS
1655 if (WIFSTOPPED(status))
1656 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
1657 childpid, WSTOPSIG(status), WEXITSTATUS(status));
1658 if (WIFSIGNALED(status))
1659 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
1660 childpid, WTERMSIG(status), WEXITSTATUS(status));
1661 if (WIFEXITED(status))
1662 debug_printf_jobs("pid %d exited, exitcode %d\n",
1663 childpid, WEXITSTATUS(status));
1665 /* Were we asked to wait for fg pipe? */
1668 for (i = 0; i < fg_pipe->num_progs; i++) {
1669 debug_printf_jobs("check pid %d\n", fg_pipe->progs[i].pid);
1670 if (fg_pipe->progs[i].pid == childpid) {
1671 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
1673 fg_pipe->progs[i].pid = 0;
1674 fg_pipe->running_progs--;
1675 if (i == fg_pipe->num_progs - 1)
1676 /* last process gives overall exitstatus */
1677 rcode = WEXITSTATUS(status);
1679 fg_pipe->progs[i].is_stopped = 1;
1680 fg_pipe->stopped_progs++;
1682 debug_printf_jobs("fg_pipe: running_progs %d stopped_progs %d\n",
1683 fg_pipe->running_progs, fg_pipe->stopped_progs);
1684 if (fg_pipe->running_progs - fg_pipe->stopped_progs <= 0) {
1685 /* All processes in fg pipe have exited/stopped */
1687 if (fg_pipe->running_progs)
1688 insert_bg_job(fg_pipe);
1692 /* There are still running processes in the fg pipe */
1696 /* fall through to searching process in bg pipes */
1700 /* We asked to wait for bg or orphaned children */
1701 /* No need to remember exitcode in this case */
1702 for (pi = job_list; pi; pi = pi->next) {
1704 while (prognum < pi->num_progs) {
1705 if (pi->progs[prognum].pid == childpid)
1706 goto found_pi_and_prognum;
1712 /* Happens when shell is used as init process (init=/bin/sh) */
1713 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
1717 found_pi_and_prognum:
1720 pi->progs[prognum].pid = 0;
1721 pi->running_progs--;
1722 if (!pi->running_progs) {
1723 printf(JOB_STATUS_FORMAT, pi->jobid,
1724 "Done", pi->cmdtext);
1725 delete_finished_bg_job(pi);
1729 pi->stopped_progs++;
1730 pi->progs[prognum].is_stopped = 1;
1735 /* wait found no children or failed */
1737 if (childpid && errno != ECHILD)
1738 bb_perror_msg("waitpid");
1743 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
1746 int rcode = checkjobs(fg_pipe);
1747 /* Job finished, move the shell to the foreground */
1748 p = getpgid(0); /* pgid of our process */
1749 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
1750 if (tcsetpgrp(interactive_fd, p) && errno != ENOTTY)
1751 bb_perror_msg("tcsetpgrp-4a");
1756 /* run_pipe() starts all the jobs, but doesn't wait for anything
1757 * to finish. See checkjobs().
1759 * return code is normally -1, when the caller has to wait for children
1760 * to finish to determine the exit status of the pipe. If the pipe
1761 * is a simple builtin command, however, the action is done by the
1762 * time run_pipe returns, and the exit code is provided as the
1765 * The input of the pipe is always stdin, the output is always
1766 * stdout. The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
1767 * because it tries to avoid running the command substitution in
1768 * subshell, when that is in fact necessary. The subshell process
1769 * now has its stdout directed to the input of the appropriate pipe,
1770 * so this routine is noticeably simpler.
1772 * Returns -1 only if started some children. IOW: we have to
1773 * mask out retvals of builtins etc with 0xff!
1775 static int run_pipe(struct pipe *pi)
1779 int pipefds[2]; /* pipefds[0] is for reading */
1780 struct child_prog *child;
1781 const struct built_in_command *x;
1783 /* it is not always needed, but we aim to smaller code */
1784 int squirrel[] = { -1, -1, -1 };
1786 const int single_fg = (pi->num_progs == 1 && pi->followup != PIPE_BG);
1788 debug_printf_exec("run_pipe start: single_fg=%d\n", single_fg);
1793 pi->running_progs = 1;
1794 pi->stopped_progs = 0;
1796 /* Check if this is a simple builtin (not part of a pipe).
1797 * Builtins within pipes have to fork anyway, and are handled in
1798 * pseudo_exec. "echo foo | read bar" doesn't work on bash, either.
1800 child = &(pi->progs[0]);
1801 if (single_fg && child->group && child->subshell == 0) {
1802 debug_printf("non-subshell grouping\n");
1803 setup_redirects(child, squirrel);
1804 debug_printf_exec(": run_list\n");
1805 rcode = run_list(child->group) & 0xff;
1806 restore_redirects(squirrel);
1807 debug_printf_exec("run_pipe return %d\n", rcode);
1811 if (single_fg && child->argv != NULL) {
1812 char **argv_expanded;
1813 char **argv = child->argv;
1815 for (i = 0; is_assignment(argv[i]); i++)
1817 if (i != 0 && argv[i] == NULL) {
1818 /* assignments, but no command: set the local environment */
1819 for (i = 0; argv[i] != NULL; i++) {
1820 debug_printf("local environment set: %s\n", argv[i]);
1821 p = expand_string_to_string(argv[i]);
1822 set_local_var(p, 0);
1824 return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */
1826 for (i = 0; is_assignment(argv[i]); i++) {
1827 p = expand_string_to_string(argv[i]);
1831 for (x = bltins; x->cmd; x++) {
1832 if (strcmp(argv[i], x->cmd) == 0) {
1833 if (x->function == builtin_exec && argv[i+1] == NULL) {
1834 debug_printf("magic exec\n");
1835 setup_redirects(child, NULL);
1836 return EXIT_SUCCESS;
1838 debug_printf("builtin inline %s\n", argv[0]);
1839 /* XXX setup_redirects acts on file descriptors, not FILEs.
1840 * This is perfect for work that comes after exec().
1841 * Is it really safe for inline use? Experimentally,
1842 * things seem to work with glibc. */
1843 setup_redirects(child, squirrel);
1844 debug_printf_exec(": builtin '%s' '%s'...\n", x->cmd, argv[i+1]);
1845 //sp: if (child->sp) /* btw we can do it unconditionally... */
1846 argv_expanded = expand_strvec_to_strvec(argv + i);
1847 rcode = x->function(argv_expanded) & 0xff;
1848 free(argv_expanded);
1849 restore_redirects(squirrel);
1850 debug_printf_exec("run_pipe return %d\n", rcode);
1854 #if ENABLE_FEATURE_SH_STANDALONE
1856 int a = find_applet_by_name(argv[i]);
1857 if (a >= 0 && APPLET_IS_NOFORK(a)) {
1858 setup_redirects(child, squirrel);
1859 save_nofork_data(&nofork_save);
1860 argv_expanded = argv + i;
1861 //sp: if (child->sp)
1862 argv_expanded = expand_strvec_to_strvec(argv + i);
1863 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n", argv_expanded[0], argv_expanded[1]);
1864 rcode = run_nofork_applet_prime(&nofork_save, a, argv_expanded) & 0xff;
1865 free(argv_expanded);
1866 restore_redirects(squirrel);
1867 debug_printf_exec("run_pipe return %d\n", rcode);
1874 /* Disable job control signals for shell (parent) and
1875 * for initial child code after fork */
1876 set_jobctrl_sighandler(SIG_IGN);
1878 /* Going to fork a child per each pipe member */
1879 pi->running_progs = 0;
1882 for (i = 0; i < pi->num_progs; i++) {
1883 child = &(pi->progs[i]);
1885 debug_printf_exec(": pipe member '%s' '%s'...\n", child->argv[0], child->argv[1]);
1887 debug_printf_exec(": pipe member with no argv\n");
1889 /* pipes are inserted between pairs of commands */
1892 if ((i + 1) < pi->num_progs)
1895 child->pid = BB_MMU ? fork() : vfork();
1896 if (!child->pid) { /* child */
1897 if (ENABLE_HUSH_JOB)
1898 die_sleep = 0; /* let nofork's xfuncs die */
1900 /* Every child adds itself to new process group
1901 * with pgid == pid_of_first_child_in_pipe */
1902 if (run_list_level == 1 && interactive_fd) {
1904 /* Don't do pgrp restore anymore on fatal signals */
1905 set_fatal_sighandler(SIG_DFL);
1907 if (pgrp < 0) /* true for 1st process only */
1909 if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
1910 /* We do it in *every* child, not just first,
1912 tcsetpgrp(interactive_fd, pgrp);
1916 xmove_fd(nextin, 0);
1917 xmove_fd(pipefds[1], 1); /* write end */
1919 close(pipefds[0]); /* read end */
1920 /* Like bash, explicit redirects override pipes,
1921 * and the pipe fd is available for dup'ing. */
1922 setup_redirects(child, NULL);
1924 /* Restore default handlers just prior to exec */
1925 set_jobctrl_sighandler(SIG_DFL);
1926 set_misc_sighandler(SIG_DFL);
1927 signal(SIGCHLD, SIG_DFL);
1928 pseudo_exec(child); /* does not return */
1931 if (child->pid < 0) { /* [v]fork failed */
1932 /* Clearly indicate, was it fork or vfork */
1933 bb_perror_msg(BB_MMU ? "fork" : "vfork");
1935 pi->running_progs++;
1937 /* Second and next children need to know pid of first one */
1939 pi->pgrp = child->pid;
1945 if ((i + 1) < pi->num_progs)
1946 close(pipefds[1]); /* write end */
1947 /* Pass read (output) pipe end to next iteration */
1948 nextin = pipefds[0];
1951 if (!pi->running_progs) {
1952 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
1956 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->running_progs);
1960 #ifndef debug_print_tree
1961 static void debug_print_tree(struct pipe *pi, int lvl)
1963 static const char *PIPE[] = {
1969 static const char *RES[] = {
1970 [RES_NONE ] = "NONE" ,
1973 [RES_THEN ] = "THEN" ,
1974 [RES_ELIF ] = "ELIF" ,
1975 [RES_ELSE ] = "ELSE" ,
1978 #if ENABLE_HUSH_LOOPS
1979 [RES_FOR ] = "FOR" ,
1980 [RES_WHILE] = "WHILE",
1981 [RES_UNTIL] = "UNTIL",
1983 [RES_DONE ] = "DONE" ,
1986 [RES_XXXX ] = "XXXX" ,
1987 [RES_SNTX ] = "SNTX" ,
1994 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
1995 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
1997 while (prn < pi->num_progs) {
1998 struct child_prog *child = &pi->progs[prn];
1999 char **argv = child->argv;
2001 fprintf(stderr, "%*s prog %d", lvl*2, "", prn);
2003 fprintf(stderr, " group %s: (argv=%p)\n",
2004 (child->subshell ? "()" : "{}"),
2006 debug_print_tree(child->group, lvl+1);
2010 if (argv) while (*argv) {
2011 fprintf(stderr, " '%s'", *argv);
2014 fprintf(stderr, "\n");
2023 /* NB: called by pseudo_exec, and therefore must not modify any
2024 * global data until exec/_exit (we can be a child after vfork!) */
2025 static int run_list(struct pipe *pi)
2028 #if ENABLE_HUSH_LOOPS
2029 char *for_varname = NULL;
2030 char **for_lcur = NULL;
2031 char **for_list = NULL;
2035 int rcode = 0; /* probably for gcc only */
2036 int flag_restore = 0;
2038 int if_code = 0, next_if_code = 0; /* need double-buffer to handle elif */
2040 enum { if_code = 0, next_if_code = 0 };
2042 reserved_style rword;
2043 reserved_style skip_more_for_this_rword = RES_XXXX;
2045 debug_printf_exec("run_list start lvl %d\n", run_list_level + 1);
2047 #if ENABLE_HUSH_LOOPS
2048 /* check syntax for "for" */
2049 for (rpipe = pi; rpipe; rpipe = rpipe->next) {
2050 if ((rpipe->res_word == RES_IN || rpipe->res_word == RES_FOR)
2051 && (rpipe->next == NULL)
2053 syntax("malformed for"); /* no IN or no commands after IN */
2054 debug_printf_exec("run_list lvl %d return 1\n", run_list_level);
2057 if ((rpipe->res_word == RES_IN && rpipe->next->res_word == RES_IN && rpipe->next->progs[0].argv != NULL)
2058 || (rpipe->res_word == RES_FOR && rpipe->next->res_word != RES_IN)
2060 /* TODO: what is tested in the first condition? */
2061 syntax("malformed for"); /* 2nd condition: not followed by IN */
2062 debug_printf_exec("run_list lvl %d return 1\n", run_list_level);
2071 /* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
2072 * We are saving state before entering outermost list ("while...done")
2073 * so that ctrl-Z will correctly background _entire_ outermost list,
2074 * not just a part of it (like "sleep 1 | exit 2") */
2075 if (++run_list_level == 1 && interactive_fd) {
2076 if (sigsetjmp(toplevel_jb, 1)) {
2077 /* ctrl-Z forked and we are parent; or ctrl-C.
2078 * Sighandler has longjmped us here */
2079 signal(SIGINT, SIG_IGN);
2080 signal(SIGTSTP, SIG_IGN);
2081 /* Restore level (we can be coming from deep inside
2084 #if ENABLE_FEATURE_SH_STANDALONE
2085 if (nofork_save.saved) { /* if save area is valid */
2086 debug_printf_jobs("exiting nofork early\n");
2087 restore_nofork_data(&nofork_save);
2091 /* ctrl-Z has forked and stored pid of the child in pi->pid.
2092 * Remember this child as background job */
2095 /* ctrl-C. We just stop doing whatever we were doing */
2101 /* ctrl-Z handler will store pid etc in pi */
2104 #if ENABLE_FEATURE_SH_STANDALONE
2105 nofork_save.saved = 0; /* in case we will run a nofork later */
2107 signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z);
2108 signal(SIGINT, handler_ctrl_c);
2112 for (; pi; pi = flag_restore ? rpipe : pi->next) {
2113 //why? int save_num_progs;
2114 rword = pi->res_word;
2115 #if ENABLE_HUSH_LOOPS
2116 if (rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR) {
2124 debug_printf_exec(": rword=%d if_code=%d next_if_code=%d skip_more=%d\n",
2125 rword, if_code, next_if_code, skip_more_for_this_rword);
2126 if (rword == skip_more_for_this_rword && flag_skip) {
2127 if (pi->followup == PIPE_SEQ)
2132 skip_more_for_this_rword = RES_XXXX;
2134 if (rword == RES_THEN || rword == RES_ELSE)
2135 if_code = next_if_code;
2136 if (rword == RES_THEN && if_code)
2138 if (rword == RES_ELSE && !if_code)
2140 if (rword == RES_ELIF && !if_code)
2143 #if ENABLE_HUSH_LOOPS
2144 if (rword == RES_FOR && pi->num_progs) {
2146 /* first loop through for */
2147 /* if no variable values after "in" we skip "for" */
2148 if (!pi->next->progs->argv)
2150 /* create list of variable values */
2151 for_list = expand_strvec_to_strvec(pi->next->progs->argv);
2152 for_lcur = for_list;
2153 for_varname = pi->progs->argv[0];
2154 pi->progs->argv[0] = NULL;
2157 free(pi->progs->argv[0]);
2159 /* for loop is over, clean up */
2163 pi->progs->argv[0] = for_varname;
2166 /* insert next value from for_lcur */
2167 /* vda: does it need escaping? */
2168 pi->progs->argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
2170 if (rword == RES_IN)
2172 if (rword == RES_DO) {
2176 if (rword == RES_DONE) {
2184 if (pi->num_progs == 0)
2186 //why? save_num_progs = pi->num_progs;
2187 debug_printf_exec(": run_pipe with %d members\n", pi->num_progs);
2188 rcode = run_pipe(pi);
2190 /* We only ran a builtin: rcode was set by the return value
2191 * of run_pipe(), and we don't need to wait for anything. */
2192 } else if (pi->followup == PIPE_BG) {
2193 /* What does bash do with attempts to background builtins? */
2194 /* Even bash 3.2 doesn't do that well with nested bg:
2195 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
2196 * I'm NOT treating inner &'s as jobs */
2198 if (run_list_level == 1)
2201 rcode = EXIT_SUCCESS;
2204 if (run_list_level == 1 && interactive_fd) {
2205 /* waits for completion, then fg's main shell */
2206 rcode = checkjobs_and_fg_shell(pi);
2210 /* this one just waits for completion */
2211 rcode = checkjobs(pi);
2213 debug_printf_exec(": checkjobs returned %d\n", rcode);
2215 debug_printf_exec(": setting last_return_code=%d\n", rcode);
2216 last_return_code = rcode;
2217 //why? pi->num_progs = save_num_progs;
2219 if (rword == RES_IF || rword == RES_ELIF)
2220 next_if_code = rcode; /* can be overwritten a number of times */
2222 #if ENABLE_HUSH_LOOPS
2223 if (rword == RES_WHILE)
2224 flag_rep = !last_return_code;
2225 if (rword == RES_UNTIL)
2226 flag_rep = last_return_code;
2228 if ((rcode == EXIT_SUCCESS && pi->followup == PIPE_OR)
2229 || (rcode != EXIT_SUCCESS && pi->followup == PIPE_AND)
2231 skip_more_for_this_rword = rword;
2238 /* ctrl-Z forked somewhere in the past, we are the child,
2239 * and now we completed running the list. Exit. */
2243 if (!--run_list_level && interactive_fd) {
2244 signal(SIGTSTP, SIG_IGN);
2245 signal(SIGINT, SIG_IGN);
2248 debug_printf_exec("run_list lvl %d return %d\n", run_list_level + 1, rcode);
2252 /* return code is the exit status of the pipe */
2253 static int free_pipe(struct pipe *pi, int indent)
2256 struct child_prog *child;
2257 struct redir_struct *r, *rnext;
2258 int a, i, ret_code = 0;
2260 if (pi->stopped_progs > 0)
2262 debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid());
2263 for (i = 0; i < pi->num_progs; i++) {
2264 child = &pi->progs[i];
2265 debug_printf_clean("%s command %d:\n", indenter(indent), i);
2267 for (a = 0, p = child->argv; *p; a++, p++) {
2268 debug_printf_clean("%s argv[%d] = %s\n", indenter(indent), a, *p);
2270 free_strings(child->argv);
2272 } else if (child->group) {
2273 debug_printf_clean("%s begin group (subshell:%d)\n", indenter(indent), child->subshell);
2274 ret_code = free_pipe_list(child->group, indent+3);
2275 debug_printf_clean("%s end group\n", indenter(indent));
2277 debug_printf_clean("%s (nil)\n", indenter(indent));
2279 for (r = child->redirects; r; r = rnext) {
2280 debug_printf_clean("%s redirect %d%s", indenter(indent), r->fd, redir_table[r->type].descrip);
2282 /* guard against the case >$FOO, where foo is unset or blank */
2284 debug_printf_clean(" %s\n", r->glob_word[0]);
2285 free_strings(r->glob_word);
2286 r->glob_word = NULL;
2289 debug_printf_clean("&%d\n", r->dup);
2294 child->redirects = NULL;
2296 free(pi->progs); /* children are an array, they get freed all at once */
2305 static int free_pipe_list(struct pipe *head, int indent)
2307 int rcode = 0; /* if list has no members */
2308 struct pipe *pi, *next;
2310 for (pi = head; pi; pi = next) {
2311 debug_printf_clean("%s pipe reserved mode %d\n", indenter(indent), pi->res_word);
2312 rcode = free_pipe(pi, indent);
2313 debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup);
2315 /*pi->next = NULL;*/
2321 /* Select which version we will use */
2322 static int run_and_free_list(struct pipe *pi)
2325 debug_printf_exec("run_and_free_list entered\n");
2327 debug_printf_exec(": run_list with %d members\n", pi->num_progs);
2328 rcode = run_list(pi);
2330 /* free_pipe_list has the side effect of clearing memory.
2331 * In the long run that function can be merged with run_list,
2332 * but doing that now would hobble the debugging effort. */
2333 free_pipe_list(pi, /* indent: */ 0);
2334 debug_printf_exec("run_nad_free_list return %d\n", rcode);
2338 /* Whoever decided to muck with glob internal data is AN IDIOT! */
2339 /* uclibc happily changed the way it works (and it has rights to do so!),
2340 all hell broke loose (SEGVs) */
2342 /* The API for glob is arguably broken. This routine pushes a non-matching
2343 * string into the output structure, removing non-backslashed backslashes.
2344 * If someone can prove me wrong, by performing this function within the
2345 * original glob(3) api, feel free to rewrite this routine into oblivion.
2346 * XXX broken if the last character is '\\', check that before calling.
2348 static char **globhack(const char *src, char **strings)
2354 for (cnt = 1, s = src; s && *s; s++) {
2355 if (*s == '\\') s++;
2358 v = dest = xmalloc(cnt);
2359 for (s = src; s && *s; s++, dest++) {
2360 if (*s == '\\') s++;
2365 return add_string_to_strings(strings, v);
2368 /* XXX broken if the last character is '\\', check that before calling */
2369 static int glob_needed(const char *s)
2374 if (strchr("*[?", *s))
2380 static int xglob(o_string *dest, char ***pglob)
2382 /* short-circuit for null word */
2383 /* we can code this better when the debug_printf's are gone */
2384 if (dest->length == 0) {
2385 if (dest->nonnull) {
2386 /* bash man page calls this an "explicit" null */
2387 *pglob = globhack(dest->data, *pglob);
2392 if (glob_needed(dest->data)) {
2396 memset(&globdata, 0, sizeof(globdata));
2397 gr = glob(dest->data, 0, NULL, &globdata);
2398 debug_printf("glob returned %d\n", gr);
2399 if (gr == GLOB_NOSPACE)
2400 bb_error_msg_and_die("out of memory during glob");
2401 if (gr == GLOB_NOMATCH) {
2402 debug_printf("globhack returned %d\n", gr);
2403 /* quote removal, or more accurately, backslash removal */
2404 *pglob = globhack(dest->data, *pglob);
2405 globfree(&globdata);
2408 if (gr != 0) { /* GLOB_ABORTED ? */
2409 bb_error_msg("glob(3) error %d", gr);
2411 if (globdata.gl_pathv && globdata.gl_pathv[0])
2412 *pglob = add_strings_to_strings(1, *pglob, globdata.gl_pathv);
2413 globfree(&globdata);
2417 *pglob = globhack(dest->data, *pglob);
2421 /* expand_strvec_to_strvec() takes a list of strings, expands
2422 * all variable references within and returns a pointer to
2423 * a list of expanded strings, possibly with larger number
2424 * of strings. (Think VAR="a b"; echo $VAR).
2425 * This new list is allocated as a single malloc block.
2426 * NULL-terminated list of char* pointers is at the beginning of it,
2427 * followed by strings themself.
2428 * Caller can deallocate entire list by single free(list). */
2431 * count_XXX estimates size of the block we need. It's okay
2432 * to over-estimate sizes a bit, if it makes code simpler */
2433 static int count_ifs(const char *str)
2436 debug_printf_expand("count_ifs('%s') ifs='%s'", str, ifs);
2438 str += strcspn(str, ifs);
2440 str++; /* str += strspn(str, ifs); */
2441 cnt++; /* cnt += strspn(str, ifs); - but this code is larger */
2443 debug_printf_expand(" return %d\n", cnt);
2447 static void count_var_expansion_space(int *countp, int *lenp, char *arg)
2452 int count = *countp;
2456 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL))) {
2459 p = strchr(p, SPECIAL_VAR_SYMBOL);
2462 switch (first_ch & 0x7f) {
2463 /* high bit in 1st_ch indicates that var is double-quoted */
2465 case '!': /* bg pid */
2466 case '?': /* exitcode */
2467 case '#': /* argc */
2468 len += sizeof(int)*3 + 1; /* enough for int */
2472 for (i = 1; global_argv[i]; i++) {
2473 len += strlen(global_argv[i]) + 1;
2475 if (!(first_ch & 0x80))
2476 count += count_ifs(global_argv[i]);
2481 arg[0] = first_ch & 0x7f;
2482 if (isdigit(arg[0])) {
2485 if (i < global_argc)
2486 val = global_argv[i];
2488 val = lookup_param(arg);
2490 *p = SPECIAL_VAR_SYMBOL;
2493 len += strlen(val) + 1;
2494 if (!(first_ch & 0x80))
2495 count += count_ifs(val);
2501 len += strlen(arg) + 1;
2507 /* Store given string, finalizing the word and starting new one whenever
2508 * we encounter ifs char(s). This is used for expanding variable values.
2509 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
2510 static int expand_on_ifs(char **list, int n, char **posp, const char *str)
2514 int word_len = strcspn(str, ifs);
2516 memcpy(pos, str, word_len); /* store non-ifs chars */
2520 if (!*str) /* EOL - do not finalize word */
2523 if (n) debug_printf_expand("expand_on_ifs finalized list[%d]=%p '%s' "
2524 "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1],
2525 strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos);
2527 str += strspn(str, ifs); /* skip ifs chars */
2533 /* Expand all variable references in given string, adding words to list[]
2534 * at n, n+1,... positions. Return updated n (so that list[n] is next one
2535 * to be filled). This routine is extremely tricky: has to deal with
2536 * variables/parameters with whitespace, $* and $@, and constructs like
2537 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
2538 /* NB: another bug is that we cannot detect empty strings yet:
2539 * "" or $empty"" expands to zero words, has to expand to empty word */
2540 static int expand_vars_to_list(char **list, int n, char **posp, char *arg, char or_mask)
2542 /* or_mask is either 0 (normal case) or 0x80
2543 * (expansion of right-hand side of assignment == 1-element expand) */
2545 char first_ch, ored_ch;
2553 if (n) debug_printf_expand("expand_vars_to_list finalized list[%d]=%p '%s' "
2554 "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1],
2555 strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos);
2558 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL))) {
2559 memcpy(pos, arg, p - arg);
2562 p = strchr(p, SPECIAL_VAR_SYMBOL);
2564 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
2565 ored_ch |= first_ch;
2567 switch (first_ch & 0x7f) {
2568 /* Highest bit in first_ch indicates that var is double-quoted */
2570 /* FIXME: (echo $$) should still print pid of main shell */
2571 val = utoa(getpid()); /* rootpid? */
2573 case '!': /* bg pid */
2574 val = last_bg_pid ? utoa(last_bg_pid) : (char*)"";
2576 case '?': /* exitcode */
2577 val = utoa(last_return_code);
2579 case '#': /* argc */
2580 val = utoa(global_argc ? global_argc-1 : 0);
2585 if (!global_argv[i])
2587 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
2588 while (global_argv[i]) {
2589 n = expand_on_ifs(list, n, &pos, global_argv[i]);
2590 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, global_argc-1);
2591 if (global_argv[i++][0] && global_argv[i]) {
2592 /* this argv[] is not empty and not last:
2593 * put terminating NUL, start new word */
2595 if (n) debug_printf_expand("expand_vars_to_list 2 finalized list[%d]=%p '%s' "
2596 "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1],
2597 strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos);
2602 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
2603 * and in this case should treat it like '$*' - see 'else...' below */
2604 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
2606 strcpy(pos, global_argv[i]);
2607 pos += strlen(global_argv[i]);
2608 if (++i >= global_argc)
2611 if (n) debug_printf_expand("expand_vars_to_list 3 finalized list[%d]=%p '%s' "
2612 "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1],
2613 strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos);
2616 } else { /* quoted $*: add as one word */
2618 strcpy(pos, global_argv[i]);
2619 pos += strlen(global_argv[i]);
2620 if (!global_argv[++i])
2629 arg[0] = first_ch & 0x7f;
2630 if (isdigit(arg[0])) {
2633 if (i < global_argc)
2634 val = global_argv[i];
2636 val = lookup_param(arg);
2638 *p = SPECIAL_VAR_SYMBOL;
2639 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2641 n = expand_on_ifs(list, n, &pos, val);
2644 } /* else: quoted $VAR, val will be appended at pos */
2652 debug_printf_expand("expand_vars_to_list adding tail '%s' at %p\n", arg, pos);
2654 pos += strlen(arg) + 1;
2655 if (pos == list[n-1] + 1) { /* expansion is empty */
2656 if (!(ored_ch & 0x80)) { /* all vars were not quoted... */
2657 debug_printf_expand("expand_vars_to_list list[%d] empty, going back\n", n);
2667 static char **expand_variables(char **argv, char or_mask)
2672 char *pos, **v, **list;
2675 if (!*v) debug_printf_expand("count_var_expansion_space: "
2676 "argv[0]=NULL count=%d len=%d alloc_space=%d\n",
2677 count, len, sizeof(char*) * count + len);
2679 count_var_expansion_space(&count, &len, *v);
2680 debug_printf_expand("count_var_expansion_space: "
2681 "'%s' count=%d len=%d alloc_space=%d\n",
2682 *v, count, len, sizeof(char*) * count + len);
2685 len += sizeof(char*) * count; /* total to alloc */
2686 list = xmalloc(len);
2687 pos = (char*)(list + count);
2688 debug_printf_expand("list=%p, list[0] should be %p\n", list, pos);
2692 n = expand_vars_to_list(list, n, &pos, *v++, or_mask);
2694 if (n) debug_printf_expand("finalized list[%d]=%p '%s' "
2695 "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1],
2696 strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos);
2703 debug_printf_expand("list[%d]=%p '%s'\n", m, list[m], list[m]);
2706 debug_printf_expand("used_space=%d\n", pos - (char*)list);
2709 if (ENABLE_HUSH_DEBUG)
2710 if (pos - (char*)list > len)
2711 bb_error_msg_and_die("BUG in varexp");
2715 static char **expand_strvec_to_strvec(char **argv)
2717 return expand_variables(argv, 0);
2720 static char *expand_string_to_string(const char *str)
2722 char *argv[2], **list;
2724 argv[0] = (char*)str;
2726 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
2727 if (ENABLE_HUSH_DEBUG)
2728 if (!list[0] || list[1])
2729 bb_error_msg_and_die("BUG in varexp2");
2730 /* actually, just move string 2*sizeof(char*) bytes back */
2731 strcpy((char*)list, list[0]);
2732 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2736 static char* expand_strvec_to_string(char **argv)
2740 list = expand_variables(argv, 0x80);
2741 /* Convert all NULs to spaces */
2745 if (ENABLE_HUSH_DEBUG)
2746 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2747 bb_error_msg_and_die("BUG in varexp3");
2748 list[n][-1] = ' '; /* TODO: or to ifs[0]? */
2752 strcpy((char*)list, list[0]);
2753 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2757 /* This is used to get/check local shell variables */
2758 static struct variable *get_local_var(const char *name)
2760 struct variable *cur;
2766 for (cur = top_var; cur; cur = cur->next) {
2767 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
2773 /* str holds "NAME=VAL" and is expected to be malloced.
2774 * We take ownership of it. */
2775 static int set_local_var(char *str, int flg_export)
2777 struct variable *cur;
2781 value = strchr(str, '=');
2782 if (!value) { /* not expected to ever happen? */
2787 name_len = value - str + 1; /* including '=' */
2788 cur = top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
2790 if (strncmp(cur->varstr, str, name_len) != 0) {
2792 /* Bail out. Note that now cur points
2793 * to last var in linked list */
2799 /* We found an existing var with this name */
2801 if (cur->flg_read_only) {
2802 bb_error_msg("%s: readonly variable", str);
2806 unsetenv(str); /* just in case */
2808 if (strcmp(cur->varstr, str) == 0) {
2813 if (cur->max_len >= strlen(str)) {
2814 /* This one is from startup env, reuse space */
2815 strcpy(cur->varstr, str);
2818 /* max_len == 0 signifies "malloced" var, which we can
2819 * (and has to) free */
2823 goto set_str_and_exp;
2826 /* Not found - create next variable struct */
2827 cur->next = xzalloc(sizeof(*cur));
2834 cur->flg_export = 1;
2835 if (cur->flg_export)
2836 return putenv(cur->varstr);
2840 static void unset_local_var(const char *name)
2842 struct variable *cur;
2843 struct variable *prev = prev; /* for gcc */
2848 name_len = strlen(name);
2851 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
2852 if (cur->flg_read_only) {
2853 bb_error_msg("%s: readonly variable", name);
2856 /* prev is ok to use here because 1st variable, HUSH_VERSION,
2857 * is ro, and we cannot reach this code on the 1st pass */
2858 prev->next = cur->next;
2859 unsetenv(cur->varstr);
2870 static int is_assignment(const char *s)
2872 if (!s || !isalpha(*s))
2875 while (isalnum(*s) || *s == '_')
2880 /* the src parameter allows us to peek forward to a possible &n syntax
2881 * for file descriptor duplication, e.g., "2>&1".
2882 * Return code is 0 normally, 1 if a syntax error is detected in src.
2883 * Resource errors (in xmalloc) cause the process to exit */
2884 static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
2885 struct in_str *input)
2887 struct child_prog *child = ctx->child;
2888 struct redir_struct *redir = child->redirects;
2889 struct redir_struct *last_redir = NULL;
2891 /* Create a new redir_struct and drop it onto the end of the linked list */
2894 redir = redir->next;
2896 redir = xzalloc(sizeof(struct redir_struct));
2897 /* redir->next = NULL; */
2898 /* redir->glob_word = NULL; */
2900 last_redir->next = redir;
2902 child->redirects = redir;
2905 redir->type = style;
2906 redir->fd = (fd == -1) ? redir_table[style].default_fd : fd;
2908 debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
2910 /* Check for a '2>&1' type redirect */
2911 redir->dup = redirect_dup_num(input);
2912 if (redir->dup == -2) return 1; /* syntax error */
2913 if (redir->dup != -1) {
2914 /* Erik had a check here that the file descriptor in question
2915 * is legit; I postpone that to "run time"
2916 * A "-" representation of "close me" shows up as a -3 here */
2917 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
2919 /* We do _not_ try to open the file that src points to,
2920 * since we need to return and let src be expanded first.
2921 * Set ctx->pending_redirect, so we know what to do at the
2922 * end of the next parsed word. */
2923 ctx->pending_redirect = redir;
2928 static struct pipe *new_pipe(void)
2931 pi = xzalloc(sizeof(struct pipe));
2932 /*pi->num_progs = 0;*/
2933 /*pi->progs = NULL;*/
2934 /*pi->next = NULL;*/
2935 /*pi->followup = 0; invalid */
2937 pi->res_word = RES_NONE;
2941 static void initialize_context(struct p_context *ctx)
2944 ctx->pipe = ctx->list_head = new_pipe();
2945 ctx->pending_redirect = NULL;
2946 ctx->res_w = RES_NONE;
2947 //only ctx->parse_type is not touched... is this intentional?
2950 done_command(ctx); /* creates the memory for working child */
2953 /* normal return is 0
2954 * if a reserved word is found, and processed, return 1
2955 * should handle if, then, elif, else, fi, for, while, until, do, done.
2956 * case, function, and select are obnoxious, save those for later.
2958 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS
2959 static int reserved_word(o_string *dest, struct p_context *ctx)
2961 struct reserved_combo {
2966 /* Mostly a list of accepted follow-up reserved words.
2967 * FLAG_END means we are done with the sequence, and are ready
2968 * to turn the compound list into a command.
2969 * FLAG_START means the word must start a new compound list.
2971 static const struct reserved_combo reserved_list[] = {
2973 { "if", RES_IF, FLAG_THEN | FLAG_START },
2974 { "then", RES_THEN, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2975 { "elif", RES_ELIF, FLAG_THEN },
2976 { "else", RES_ELSE, FLAG_FI },
2977 { "fi", RES_FI, FLAG_END },
2979 #if ENABLE_HUSH_LOOPS
2980 { "for", RES_FOR, FLAG_IN | FLAG_START },
2981 { "while", RES_WHILE, FLAG_DO | FLAG_START },
2982 { "until", RES_UNTIL, FLAG_DO | FLAG_START },
2983 { "in", RES_IN, FLAG_DO },
2984 { "do", RES_DO, FLAG_DONE },
2985 { "done", RES_DONE, FLAG_END }
2989 const struct reserved_combo *r;
2991 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
2992 if (strcmp(dest->data, r->literal) != 0)
2994 debug_printf("found reserved word %s, code %d\n", r->literal, r->code);
2995 if (r->flag & FLAG_START) {
2996 struct p_context *new;
2997 debug_printf("push stack\n");
2998 #if ENABLE_HUSH_LOOPS
2999 if (ctx->res_w == RES_IN || ctx->res_w == RES_FOR) {
3000 syntax("malformed for"); /* example: 'for if' */
3001 ctx->res_w = RES_SNTX;
3006 new = xmalloc(sizeof(*new));
3007 *new = *ctx; /* physical copy */
3008 initialize_context(ctx);
3010 } else if (ctx->res_w == RES_NONE || !(ctx->old_flag & (1 << r->code))) {
3012 ctx->res_w = RES_SNTX;
3016 ctx->res_w = r->code;
3017 ctx->old_flag = r->flag;
3018 if (ctx->old_flag & FLAG_END) {
3019 struct p_context *old;
3020 debug_printf("pop stack\n");
3021 done_pipe(ctx, PIPE_SEQ);
3023 old->child->group = ctx->list_head;
3024 old->child->subshell = 0;
3025 *ctx = *old; /* physical copy */
3034 #define reserved_word(dest, ctx) ((int)0)
3037 /* Normal return is 0.
3038 * Syntax or xglob errors return 1. */
3039 static int done_word(o_string *dest, struct p_context *ctx)
3041 struct child_prog *child = ctx->child;
3042 char ***glob_target;
3045 debug_printf_parse("done_word entered: '%s' %p\n", dest->data, child);
3046 if (dest->length == 0 && !dest->nonnull) {
3047 debug_printf_parse("done_word return 0: true null, ignored\n");
3050 if (ctx->pending_redirect) {
3051 glob_target = &ctx->pending_redirect->glob_word;
3055 debug_printf_parse("done_word return 1: syntax error, groups and arglists don't mix\n");
3058 if (!child->argv && (ctx->parse_type & PARSEFLAG_SEMICOLON)) {
3059 debug_printf_parse(": checking '%s' for reserved-ness\n", dest->data);
3060 if (reserved_word(dest, ctx)) {
3061 debug_printf_parse("done_word return %d\n", (ctx->res_w == RES_SNTX));
3062 return (ctx->res_w == RES_SNTX);
3065 glob_target = &child->argv;
3067 gr = xglob(dest, glob_target);
3069 debug_printf_parse("done_word return 1: xglob returned %d\n", gr);
3074 if (ctx->pending_redirect) {
3075 /* NB: don't free_strings(ctx->pending_redirect->glob_word) here */
3076 if (ctx->pending_redirect->glob_word
3077 && ctx->pending_redirect->glob_word[0]
3078 && ctx->pending_redirect->glob_word[1]
3080 /* more than one word resulted from globbing redir */
3081 ctx->pending_redirect = NULL;
3082 bb_error_msg("ambiguous redirect");
3083 debug_printf_parse("done_word return 1: ambiguous redirect\n");
3086 ctx->pending_redirect = NULL;
3088 #if ENABLE_HUSH_LOOPS
3089 if (ctx->res_w == RES_FOR) {
3090 done_word(dest, ctx);
3091 done_pipe(ctx, PIPE_SEQ);
3094 debug_printf_parse("done_word return 0\n");
3098 /* The only possible error here is out of memory, in which case
3100 static int done_command(struct p_context *ctx)
3102 /* The child is really already in the pipe structure, so
3103 * advance the pipe counter and make a new, null child. */
3104 struct pipe *pi = ctx->pipe;
3105 struct child_prog *child = ctx->child;
3108 if (child->group == NULL
3109 && child->argv == NULL
3110 && child->redirects == NULL
3112 debug_printf_parse("done_command: skipping null cmd, num_progs=%d\n", pi->num_progs);
3113 return pi->num_progs;
3116 debug_printf_parse("done_command: ++num_progs=%d\n", pi->num_progs);
3118 debug_printf_parse("done_command: initializing, num_progs=%d\n", pi->num_progs);
3121 /* Only real trickiness here is that the uncommitted
3122 * child structure is not counted in pi->num_progs. */
3123 pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
3124 child = &pi->progs[pi->num_progs];
3126 memset(child, 0, sizeof(*child));
3127 /*child->redirects = NULL;*/
3128 /*child->argv = NULL;*/
3129 /*child->is_stopped = 0;*/
3130 /*child->group = NULL;*/
3132 //sp: /*child->sp = 0;*/
3133 //pt: child->parse_type = ctx->parse_type;
3136 /* but ctx->pipe and ctx->list_head remain unchanged */
3138 return pi->num_progs; /* used only for 0/nonzero check */
3141 static int done_pipe(struct p_context *ctx, pipe_style type)
3146 debug_printf_parse("done_pipe entered, followup %d\n", type);
3147 not_null = done_command(ctx); /* implicit closure of previous command */
3148 ctx->pipe->followup = type;
3149 ctx->pipe->res_word = ctx->res_w;
3150 /* Without this check, even just <enter> on command line generates
3151 * tree of three NOPs (!). Which is harmless but annoying.
3152 * IOW: it is safe to do it unconditionally. */
3155 ctx->pipe->next = new_p;
3158 done_command(ctx); /* set up new pipe to accept commands */
3160 debug_printf_parse("done_pipe return 0\n");
3164 /* peek ahead in the in_str to find out if we have a "&n" construct,
3165 * as in "2>&1", that represents duplicating a file descriptor.
3166 * returns either -2 (syntax error), -1 (no &), or the number found.
3168 static int redirect_dup_num(struct in_str *input)
3170 int ch, d = 0, ok = 0;
3172 if (ch != '&') return -1;
3174 b_getch(input); /* get the & */
3178 return -3; /* "-" represents "close me" */
3180 while (isdigit(ch)) {
3181 d = d*10 + (ch-'0');
3188 bb_error_msg("ambiguous redirect");
3192 /* If a redirect is immediately preceded by a number, that number is
3193 * supposed to tell which file descriptor to redirect. This routine
3194 * looks for such preceding numbers. In an ideal world this routine
3195 * needs to handle all the following classes of redirects...
3196 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3197 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3198 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3199 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3200 * A -1 output from this program means no valid number was found, so the
3201 * caller should use the appropriate default for this redirection.
3203 static int redirect_opt_num(o_string *o)
3209 for (num = 0; num < o->length; num++) {
3210 if (!isdigit(*(o->data + num))) {
3214 /* reuse num (and save an int) */
3215 num = atoi(o->data);
3220 #if ENABLE_HUSH_TICK
3221 /* NB: currently disabled on NOMMU */
3222 static FILE *generate_stream_from_list(struct pipe *head)
3225 int pid, channel[2];
3228 /* *** NOMMU WARNING *** */
3229 /* By using vfork here, we suspend parent till child exits or execs.
3230 * If child will not do it before it fills the pipe, it can block forever
3231 * in write(STDOUT_FILENO), and parent (shell) will be also stuck.
3233 pid = BB_MMU ? fork() : vfork();
3235 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
3236 if (pid == 0) { /* child */
3237 if (ENABLE_HUSH_JOB)
3238 die_sleep = 0; /* let nofork's xfuncs die */
3239 close(channel[0]); /* NB: close _first_, then move fd! */
3240 xmove_fd(channel[1], 1);
3241 /* Prevent it from trying to handle ctrl-z etc */
3245 /* Process substitution is not considered to be usual
3246 * 'command execution'.
3247 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not. */
3248 /* Not needed, we are relying on it being disabled
3249 * everywhere outside actual command execution. */
3250 /*set_jobctrl_sighandler(SIG_IGN);*/
3251 set_misc_sighandler(SIG_DFL);
3252 /* Freeing 'head' here would break NOMMU. */
3253 _exit(run_list(head));
3256 pf = fdopen(channel[0], "r");
3258 /* 'head' is freed by the caller */
3261 /* Return code is exit status of the process that is run. */
3262 static int process_command_subs(o_string *dest,
3263 /*struct p_context *ctx,*/
3264 struct in_str *input,
3265 const char *subst_end)
3267 int retcode, ch, eol_cnt;
3268 o_string result = NULL_O_STRING;
3269 struct p_context inner;
3271 struct in_str pipe_str;
3273 initialize_context(&inner);
3275 /* recursion to generate command */
3276 retcode = parse_stream(&result, &inner, input, subst_end);
3278 return retcode; /* syntax error or EOF */
3279 done_word(&result, &inner);
3280 done_pipe(&inner, PIPE_SEQ);
3283 p = generate_stream_from_list(inner.list_head);
3286 close_on_exec_on(fileno(p));
3287 setup_file_in_str(&pipe_str, p);
3289 /* now send results of command back into original context */
3291 while ((ch = b_getch(&pipe_str)) != EOF) {
3297 b_addqchr(dest, '\n', dest->o_quote);
3300 b_addqchr(dest, ch, dest->o_quote);
3303 debug_printf("done reading from pipe, pclose()ing\n");
3304 /* This is the step that wait()s for the child. Should be pretty
3305 * safe, since we just read an EOF from its stdout. We could try
3306 * to do better, by using wait(), and keeping track of background jobs
3307 * at the same time. That would be a lot of work, and contrary
3308 * to the KISS philosophy of this program. */
3309 retcode = fclose(p);
3310 free_pipe_list(inner.list_head, /* indent: */ 0);
3311 debug_printf("closed FILE from child, retcode=%d\n", retcode);
3316 static int parse_group(o_string *dest, struct p_context *ctx,
3317 struct in_str *input, int ch)
3320 const char *endch = NULL;
3321 struct p_context sub;
3322 struct child_prog *child = ctx->child;
3324 debug_printf_parse("parse_group entered\n");
3327 debug_printf_parse("parse_group return 1: syntax error, groups and arglists don't mix\n");
3330 initialize_context(&sub);
3334 child->subshell = 1;
3336 rcode = parse_stream(dest, &sub, input, endch);
3338 done_word(dest, &sub); /* finish off the final word in the subcontext */
3339 done_pipe(&sub, PIPE_SEQ); /* and the final command there, too */
3340 child->group = sub.list_head;
3342 debug_printf_parse("parse_group return %d\n", rcode);
3344 /* child remains "open", available for possible redirects */
3347 /* Basically useful version until someone wants to get fancier,
3348 * see the bash man page under "Parameter Expansion" */
3349 static const char *lookup_param(const char *src)
3351 struct variable *var = get_local_var(src);
3353 return strchr(var->varstr, '=') + 1;
3357 /* return code: 0 for OK, 1 for syntax error */
3358 static int handle_dollar(o_string *dest, /*struct p_context *ctx,*/ struct in_str *input)
3360 int ch = b_peek(input); /* first character after the $ */
3361 unsigned char quote_mask = dest->o_quote ? 0x80 : 0;
3363 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
3365 b_addchr(dest, SPECIAL_VAR_SYMBOL);
3366 //sp: ctx->child->sp++;
3368 debug_printf_parse(": '%c'\n", ch);
3370 b_addchr(dest, ch | quote_mask);
3373 if (!isalnum(ch) && ch != '_')
3376 b_addchr(dest, SPECIAL_VAR_SYMBOL);
3377 } else if (isdigit(ch)) {
3379 b_addchr(dest, SPECIAL_VAR_SYMBOL);
3380 //sp: ctx->child->sp++;
3381 debug_printf_parse(": '%c'\n", ch);
3383 b_addchr(dest, ch | quote_mask);
3384 b_addchr(dest, SPECIAL_VAR_SYMBOL);
3385 } else switch (ch) {
3387 case '!': /* last bg pid */
3388 case '?': /* last exit code */
3389 case '#': /* number of args */
3390 case '*': /* args */
3391 case '@': /* args */
3392 goto make_one_char_var;
3394 b_addchr(dest, SPECIAL_VAR_SYMBOL);
3395 //sp: ctx->child->sp++;
3397 /* XXX maybe someone will try to escape the '}' */
3399 ch = b_getch(input);
3402 if (!isalnum(ch) && ch != '_') {
3403 syntax("unterminated ${name}");
3404 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
3407 debug_printf_parse(": '%c'\n", ch);
3408 b_addchr(dest, ch | quote_mask);
3411 b_addchr(dest, SPECIAL_VAR_SYMBOL);
3413 #if ENABLE_HUSH_TICK
3416 process_command_subs(dest, /*ctx,*/ input, ")");
3421 /* still unhandled, but should be eventually */
3422 bb_error_msg("unhandled syntax: $%c", ch);
3426 b_addqchr(dest, '$', dest->o_quote);
3428 debug_printf_parse("handle_dollar return 0\n");
3432 /* return code is 0 for normal exit, 1 for syntax error */
3433 static int parse_stream(o_string *dest, struct p_context *ctx,
3434 struct in_str *input, const char *end_trigger)
3438 redir_type redir_style;
3441 /* Only double-quote state is handled in the state variable dest->o_quote.
3442 * A single-quote triggers a bypass of the main loop until its mate is
3443 * found. When recursing, quote state is passed in via dest->o_quote. */
3445 debug_printf_parse("parse_stream entered, end_trigger='%s'\n", end_trigger);
3450 ch = b_getch(input);
3454 next = b_peek(input);
3456 debug_printf_parse(": ch=%c (%d) m=%d quote=%d\n",
3457 ch, ch, m, dest->o_quote);
3458 if (m == CHAR_ORDINARY
3459 || (m != CHAR_SPECIAL && dest->o_quote)
3462 syntax("unterminated \"");
3463 debug_printf_parse("parse_stream return 1: unterminated \"\n");
3466 b_addqchr(dest, ch, dest->o_quote);
3469 if (m == CHAR_IFS) {
3470 if (done_word(dest, ctx)) {
3471 debug_printf_parse("parse_stream return 1: done_word!=0\n");
3476 /* If we aren't performing a substitution, treat
3477 * a newline as a command separator.
3478 * [why we don't handle it exactly like ';'? --vda] */
3479 if (end_trigger && ch == '\n') {
3480 done_pipe(ctx, PIPE_SEQ);
3483 if ((end_trigger && strchr(end_trigger, ch))
3484 && !dest->o_quote && ctx->res_w == RES_NONE
3486 debug_printf_parse("parse_stream return 0: end_trigger char found\n");
3493 if (dest->length == 0 && !dest->o_quote) {
3496 if (ch == EOF || ch == '\n')
3501 b_addqchr(dest, ch, dest->o_quote);
3507 debug_printf_parse("parse_stream return 1: \\<eof>\n");
3510 b_addqchr(dest, '\\', dest->o_quote);
3511 b_addqchr(dest, b_getch(input), dest->o_quote);
3514 if (handle_dollar(dest, /*ctx,*/ input) != 0) {
3515 debug_printf_parse("parse_stream return 1: handle_dollar returned non-0\n");
3522 ch = b_getch(input);
3523 if (ch == EOF || ch == '\'')
3528 syntax("unterminated '");
3529 debug_printf_parse("parse_stream return 1: unterminated '\n");
3535 dest->o_quote ^= 1; /* invert */
3537 #if ENABLE_HUSH_TICK
3539 process_command_subs(dest, /*ctx,*/ input, "`");
3543 redir_fd = redirect_opt_num(dest);
3544 done_word(dest, ctx);
3545 redir_style = REDIRECT_OVERWRITE;
3547 redir_style = REDIRECT_APPEND;
3551 else if (next == '(') {
3552 syntax(">(process) not supported");
3553 debug_printf_parse("parse_stream return 1: >(process) not supported\n");
3557 setup_redirect(ctx, redir_fd, redir_style, input);
3560 redir_fd = redirect_opt_num(dest);
3561 done_word(dest, ctx);
3562 redir_style = REDIRECT_INPUT;
3564 redir_style = REDIRECT_HEREIS;
3566 } else if (next == '>') {
3567 redir_style = REDIRECT_IO;
3571 else if (next == '(') {
3572 syntax("<(process) not supported");
3573 debug_printf_parse("parse_stream return 1: <(process) not supported\n");
3577 setup_redirect(ctx, redir_fd, redir_style, input);
3580 done_word(dest, ctx);
3581 done_pipe(ctx, PIPE_SEQ);
3584 done_word(dest, ctx);
3587 done_pipe(ctx, PIPE_AND);
3589 done_pipe(ctx, PIPE_BG);
3593 done_word(dest, ctx);
3596 done_pipe(ctx, PIPE_OR);
3598 /* we could pick up a file descriptor choice here
3599 * with redirect_opt_num(), but bash doesn't do it.
3600 * "echo foo 2| cat" yields "foo 2". */
3606 if (parse_group(dest, ctx, input, ch) != 0) {
3607 debug_printf_parse("parse_stream return 1: parse_group returned non-0\n");
3613 syntax("unexpected }"); /* Proper use of this character is caught by end_trigger */
3614 debug_printf_parse("parse_stream return 1: unexpected '}'\n");
3617 if (ENABLE_HUSH_DEBUG)
3618 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
3621 /* Complain if quote? No, maybe we just finished a command substitution
3622 * that was quoted. Example:
3623 * $ echo "`cat foo` plus more"
3624 * and we just got the EOF generated by the subshell that ran "cat foo"
3625 * The only real complaint is if we got an EOF when end_trigger != NULL,
3626 * that is, we were really supposed to get end_trigger, and never got
3627 * one before the EOF. Can't use the standard "syntax error" return code,
3628 * so that parse_stream_outer can distinguish the EOF and exit smoothly. */
3629 debug_printf_parse("parse_stream return %d\n", -(end_trigger != NULL));
3635 static void set_in_charmap(const char *set, int code)
3638 charmap[(unsigned char)*set++] = code;
3641 static void update_charmap(void)
3643 /* char *ifs and char charmap[256] are both globals. */
3644 ifs = getenv("IFS");
3647 /* Precompute a list of 'flow through' behavior so it can be treated
3648 * quickly up front. Computation is necessary because of IFS.
3649 * Special case handling of IFS == " \t\n" is not implemented.
3650 * The charmap[] array only really needs two bits each,
3651 * and on most machines that would be faster (reduced L1 cache use).
3653 memset(charmap, CHAR_ORDINARY, sizeof(charmap));
3654 #if ENABLE_HUSH_TICK
3655 set_in_charmap("\\$\"`", CHAR_SPECIAL);
3657 set_in_charmap("\\$\"", CHAR_SPECIAL);
3659 set_in_charmap("<>;&|(){}#'", CHAR_ORDINARY_IF_QUOTED);
3660 set_in_charmap(ifs, CHAR_IFS); /* are ordinary if quoted */
3663 /* most recursion does not come through here, the exception is
3664 * from builtin_source() and builtin_eval() */
3665 static int parse_and_run_stream(struct in_str *inp, int parse_flag)
3667 struct p_context ctx;
3668 o_string temp = NULL_O_STRING;
3671 ctx.parse_type = parse_flag;
3672 initialize_context(&ctx);
3674 if (!(parse_flag & PARSEFLAG_SEMICOLON) || (parse_flag & PARSEFLAG_REPARSING))
3675 set_in_charmap(";$&|", CHAR_ORDINARY);
3676 #if ENABLE_HUSH_INTERACTIVE
3677 inp->promptmode = 0; /* PS1 */
3679 /* We will stop & execute after each ';' or '\n'.
3680 * Example: "sleep 9999; echo TEST" + ctrl-C:
3681 * TEST should be printed */
3682 rcode = parse_stream(&temp, &ctx, inp, ";\n");
3683 if (rcode != 1 && ctx.old_flag != 0) {
3686 if (rcode != 1 && ctx.old_flag == 0) {
3687 done_word(&temp, &ctx);
3688 done_pipe(&ctx, PIPE_SEQ);
3689 debug_print_tree(ctx.list_head, 0);
3690 debug_printf_exec("parse_stream_outer: run_and_free_list\n");
3691 run_and_free_list(ctx.list_head);
3693 if (ctx.old_flag != 0) {
3700 free_pipe_list(ctx.list_head, /* indent: */ 0);
3703 } while (rcode != -1 && !(parse_flag & PARSEFLAG_EXIT_FROM_LOOP)); /* loop on syntax errors, return on EOF */
3707 static int parse_and_run_string(const char *s, int parse_flag)
3709 struct in_str input;
3710 setup_string_in_str(&input, s);
3711 return parse_and_run_stream(&input, parse_flag);
3714 static int parse_and_run_file(FILE *f)
3717 struct in_str input;
3718 setup_file_in_str(&input, f);
3719 rcode = parse_and_run_stream(&input, PARSEFLAG_SEMICOLON);
3724 /* Make sure we have a controlling tty. If we get started under a job
3725 * aware app (like bash for example), make sure we are now in charge so
3726 * we don't fight over who gets the foreground */
3727 static void setup_job_control(void)
3731 saved_task_pgrp = shell_pgrp = getpgrp();
3732 debug_printf_jobs("saved_task_pgrp=%d\n", saved_task_pgrp);
3733 close_on_exec_on(interactive_fd);
3735 /* If we were ran as 'hush &',
3736 * sleep until we are in the foreground. */
3737 while (tcgetpgrp(interactive_fd) != shell_pgrp) {
3738 /* Send TTIN to ourself (should stop us) */
3739 kill(- shell_pgrp, SIGTTIN);
3740 shell_pgrp = getpgrp();
3743 /* Ignore job-control and misc signals. */
3744 set_jobctrl_sighandler(SIG_IGN);
3745 set_misc_sighandler(SIG_IGN);
3746 //huh? signal(SIGCHLD, SIG_IGN);
3748 /* We _must_ restore tty pgrp on fatal signals */
3749 set_fatal_sighandler(sigexit);
3751 /* Put ourselves in our own process group. */
3752 setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
3753 /* Grab control of the terminal. */
3754 tcsetpgrp(interactive_fd, getpid());
3758 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
3759 int hush_main(int argc, char **argv)
3761 static const char version_str[] ALIGN1 = "HUSH_VERSION="HUSH_VER_STR;
3762 static const struct variable const_shell_ver = {
3764 .varstr = (char*)version_str,
3765 .max_len = 1, /* 0 can provoke free(name) */
3773 struct variable *cur_var;
3777 /* Deal with HUSH_VERSION */
3778 shell_ver = const_shell_ver; /* copying struct here */
3779 top_var = &shell_ver;
3780 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
3781 /* Initialize our shell local variables with the values
3782 * currently living in the environment */
3786 char *value = strchr(*e, '=');
3787 if (value) { /* paranoia */
3788 cur_var->next = xzalloc(sizeof(*cur_var));
3789 cur_var = cur_var->next;
3790 cur_var->varstr = *e;
3791 cur_var->max_len = strlen(*e);
3792 cur_var->flg_export = 1;
3796 putenv((char *)version_str); /* reinstate HUSH_VERSION */
3798 #if ENABLE_FEATURE_EDITING
3799 line_input_state = new_line_input_t(FOR_SHELL);
3801 /* XXX what should these be while sourcing /etc/profile? */
3804 /* Initialize some more globals to non-zero values */
3806 #if ENABLE_HUSH_INTERACTIVE
3807 #if ENABLE_FEATURE_EDITING
3808 cmdedit_set_initial_prompt();
3813 if (EXIT_SUCCESS) /* otherwise is already done */
3814 last_return_code = EXIT_SUCCESS;
3816 if (argv[0] && argv[0][0] == '-') {
3817 debug_printf("sourcing /etc/profile\n");
3818 input = fopen("/etc/profile", "r");
3819 if (input != NULL) {
3820 close_on_exec_on(fileno(input));
3821 parse_and_run_file(input);
3827 while ((opt = getopt(argc, argv, "c:xif")) > 0) {
3830 global_argv = argv + optind;
3831 global_argc = argc - optind;
3832 opt = parse_and_run_string(optarg, PARSEFLAG_SEMICOLON);
3835 /* Well, we cannot just declare interactiveness,
3836 * we have to have some stuff (ctty, etc) */
3837 /* interactive_fd++; */
3844 fprintf(stderr, "Usage: sh [FILE]...\n"
3845 " or: sh -c command [args]...\n\n");
3853 /* A shell is interactive if the '-i' flag was given, or if all of
3854 * the following conditions are met:
3856 * no arguments remaining or the -s flag given
3857 * standard input is a terminal
3858 * standard output is a terminal
3859 * Refer to Posix.2, the description of the 'sh' utility. */
3860 if (argv[optind] == NULL && input == stdin
3861 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
3863 saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
3864 debug_printf("saved_tty_pgrp=%d\n", saved_tty_pgrp);
3865 if (saved_tty_pgrp >= 0) {
3866 /* try to dup to high fd#, >= 255 */
3867 interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
3868 if (interactive_fd < 0) {
3869 /* try to dup to any fd */
3870 interactive_fd = dup(STDIN_FILENO);
3871 if (interactive_fd < 0)
3875 // TODO: track & disallow any attempts of user
3876 // to (inadvertently) close/redirect it
3879 debug_printf("interactive_fd=%d\n", interactive_fd);
3880 if (interactive_fd) {
3881 fcntl(interactive_fd, F_SETFD, FD_CLOEXEC);
3882 /* Looks like they want an interactive shell */
3883 setup_job_control();
3884 /* -1 is special - makes xfuncs longjmp, not exit
3885 * (we reset die_sleep = 0 whereever we [v]fork) */
3887 if (setjmp(die_jmp)) {
3888 /* xfunc has failed! die die die */
3889 hush_exit(xfunc_error_retval);
3891 #if !ENABLE_FEATURE_SH_EXTRA_QUIET
3892 printf("\n\n%s hush - the humble shell v"HUSH_VER_STR"\n", bb_banner);
3893 printf("Enter 'help' for a list of built-in commands.\n\n");
3896 #elif ENABLE_HUSH_INTERACTIVE
3897 /* no job control compiled, only prompt/line editing */
3898 if (argv[optind] == NULL && input == stdin
3899 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
3901 interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
3902 if (interactive_fd < 0) {
3903 /* try to dup to any fd */
3904 interactive_fd = dup(STDIN_FILENO);
3905 if (interactive_fd < 0)
3910 fcntl(interactive_fd, F_SETFD, FD_CLOEXEC);
3914 if (argv[optind] == NULL) {
3915 opt = parse_and_run_file(stdin);
3917 debug_printf("\nrunning script '%s'\n", argv[optind]);
3918 global_argv = argv + optind;
3919 global_argc = argc - optind;
3920 input = xfopen(argv[optind], "r");
3921 fcntl(fileno(input), F_SETFD, FD_CLOEXEC);
3922 opt = parse_and_run_file(input);
3927 #if ENABLE_FEATURE_CLEAN_UP
3929 if (cwd != bb_msg_unknown)
3931 cur_var = top_var->next;
3933 struct variable *tmp = cur_var;
3934 if (!cur_var->max_len)
3935 free(cur_var->varstr);
3936 cur_var = cur_var->next;
3940 hush_exit(opt ? opt : last_return_code);
3945 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
3946 int lash_main(int argc, char **argv)
3948 //bb_error_msg("lash is deprecated, please use hush instead");
3949 return hush_main(argc, argv);