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1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * sh.c -- a prototype Bourne shell grammar parser
4  *      Intended to follow the original Thompson and Ritchie
5  *      "small and simple is beautiful" philosophy, which
6  *      incidentally is a good match to today's BusyBox.
7  *
8  * Copyright (C) 2000,2001  Larry Doolittle  <larry@doolittle.boa.org>
9  *
10  * Credits:
11  *      The parser routines proper are all original material, first
12  *      written Dec 2000 and Jan 2001 by Larry Doolittle.
13  *      The execution engine, the builtins, and much of the underlying
14  *      support has been adapted from busybox-0.49pre's lash,
15  *      which is Copyright (C) 2000 by Lineo, Inc., and
16  *      written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>.
17  *      That, in turn, is based in part on ladsh.c, by Michael K. Johnson and
18  *      Erik W. Troan, which they placed in the public domain.  I don't know
19  *      how much of the Johnson/Troan code has survived the repeated rewrites.
20  * Other credits:
21  *      b_addchr() derived from similar w_addchar function in glibc-2.2
22  *      setup_redirect(), redirect_opt_num(), and big chunks of main()
23  *        and many builtins derived from contributions by Erik Andersen
24  *      miscellaneous bugfixes from Matt Kraai
25  *
26  * There are two big (and related) architecture differences between
27  * this parser and the lash parser.  One is that this version is
28  * actually designed from the ground up to understand nearly all
29  * of the Bourne grammar.  The second, consequential change is that
30  * the parser and input reader have been turned inside out.  Now,
31  * the parser is in control, and asks for input as needed.  The old
32  * way had the input reader in control, and it asked for parsing to
33  * take place as needed.  The new way makes it much easier to properly
34  * handle the recursion implicit in the various substitutions, especially
35  * across continuation lines.
36  *
37  * Bash grammar not implemented: (how many of these were in original sh?)
38  *      $@ (those sure look like weird quoting rules)
39  *      $_
40  *      ! negation operator for pipes
41  *      &> and >& redirection of stdout+stderr
42  *      Brace Expansion
43  *      Tilde Expansion
44  *      fancy forms of Parameter Expansion
45  *      aliases
46  *      Arithmetic Expansion
47  *      <(list) and >(list) Process Substitution
48  *      reserved words: case, esac, select, function
49  *      Here Documents ( << word )
50  *      Functions
51  * Major bugs:
52  *      job handling woefully incomplete and buggy
53  *      reserved word execution woefully incomplete and buggy
54  * to-do:
55  *      port selected bugfixes from post-0.49 busybox lash - done?
56  *      finish implementing reserved words: for, while, until, do, done
57  *      change { and } from special chars to reserved words
58  *      builtins: break, continue, eval, return, set, trap, ulimit
59  *      test magic exec
60  *      handle children going into background
61  *      clean up recognition of null pipes
62  *      check setting of global_argc and global_argv
63  *      control-C handling, probably with longjmp
64  *      follow IFS rules more precisely, including update semantics
65  *      figure out what to do with backslash-newline
66  *      explain why we use signal instead of sigaction
67  *      propagate syntax errors, die on resource errors?
68  *      continuation lines, both explicit and implicit - done?
69  *      memory leak finding and plugging - done?
70  *      more testing, especially quoting rules and redirection
71  *      document how quoting rules not precisely followed for variable assignments
72  *      maybe change map[] to use 2-bit entries
73  *      (eventually) remove all the printf's
74  */
75 
76 #define __U_BOOT__
77 #ifdef __U_BOOT__
78 #include <malloc.h>         /* malloc, free, realloc*/
79 #include <linux/ctype.h>    /* isalpha, isdigit */
80 #include <common.h>        /* readline */
81 #include <console.h>
82 #include <bootretry.h>
83 #include <cli.h>
84 #include <cli_hush.h>
85 #include <command.h>        /* find_cmd */
86 #ifndef CONFIG_SYS_PROMPT_HUSH_PS2
87 #define CONFIG_SYS_PROMPT_HUSH_PS2	"> "
88 #endif
89 #endif
90 #ifndef __U_BOOT__
91 #include <ctype.h>     /* isalpha, isdigit */
92 #include <unistd.h>    /* getpid */
93 #include <stdlib.h>    /* getenv, atoi */
94 #include <string.h>    /* strchr */
95 #include <stdio.h>     /* popen etc. */
96 #include <glob.h>      /* glob, of course */
97 #include <stdarg.h>    /* va_list */
98 #include <errno.h>
99 #include <fcntl.h>
100 #include <getopt.h>    /* should be pretty obvious */
101 
102 #include <sys/stat.h>  /* ulimit */
103 #include <sys/types.h>
104 #include <sys/wait.h>
105 #include <signal.h>
106 
107 /* #include <dmalloc.h> */
108 
109 #if 1
110 #include "busybox.h"
111 #include "cmdedit.h"
112 #else
113 #define applet_name "hush"
114 #include "standalone.h"
115 #define hush_main main
116 #undef CONFIG_FEATURE_SH_FANCY_PROMPT
117 #define BB_BANNER
118 #endif
119 #endif
120 #define SPECIAL_VAR_SYMBOL 03
121 #define SUBSTED_VAR_SYMBOL 04
122 #ifndef __U_BOOT__
123 #define FLAG_EXIT_FROM_LOOP 1
124 #define FLAG_PARSE_SEMICOLON (1 << 1)		/* symbol ';' is special for parser */
125 #define FLAG_REPARSING       (1 << 2)		/* >= 2nd pass */
126 
127 #endif
128 
129 #ifdef __U_BOOT__
130 DECLARE_GLOBAL_DATA_PTR;
131 
132 #define EXIT_SUCCESS 0
133 #define EOF -1
134 #define syntax() syntax_err()
135 #define xstrdup strdup
136 #define error_msg printf
137 #else
138 typedef enum {
139 	REDIRECT_INPUT     = 1,
140 	REDIRECT_OVERWRITE = 2,
141 	REDIRECT_APPEND    = 3,
142 	REDIRECT_HEREIS    = 4,
143 	REDIRECT_IO        = 5
144 } redir_type;
145 
146 /* The descrip member of this structure is only used to make debugging
147  * output pretty */
148 struct {int mode; int default_fd; char *descrip;} redir_table[] = {
149 	{ 0,                         0, "()" },
150 	{ O_RDONLY,                  0, "<"  },
151 	{ O_CREAT|O_TRUNC|O_WRONLY,  1, ">"  },
152 	{ O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
153 	{ O_RDONLY,                 -1, "<<" },
154 	{ O_RDWR,                    1, "<>" }
155 };
156 #endif
157 
158 typedef enum {
159 	PIPE_SEQ = 1,
160 	PIPE_AND = 2,
161 	PIPE_OR  = 3,
162 	PIPE_BG  = 4,
163 } pipe_style;
164 
165 /* might eventually control execution */
166 typedef enum {
167 	RES_NONE  = 0,
168 	RES_IF    = 1,
169 	RES_THEN  = 2,
170 	RES_ELIF  = 3,
171 	RES_ELSE  = 4,
172 	RES_FI    = 5,
173 	RES_FOR   = 6,
174 	RES_WHILE = 7,
175 	RES_UNTIL = 8,
176 	RES_DO    = 9,
177 	RES_DONE  = 10,
178 	RES_XXXX  = 11,
179 	RES_IN    = 12,
180 	RES_SNTX  = 13
181 } reserved_style;
182 #define FLAG_END   (1<<RES_NONE)
183 #define FLAG_IF    (1<<RES_IF)
184 #define FLAG_THEN  (1<<RES_THEN)
185 #define FLAG_ELIF  (1<<RES_ELIF)
186 #define FLAG_ELSE  (1<<RES_ELSE)
187 #define FLAG_FI    (1<<RES_FI)
188 #define FLAG_FOR   (1<<RES_FOR)
189 #define FLAG_WHILE (1<<RES_WHILE)
190 #define FLAG_UNTIL (1<<RES_UNTIL)
191 #define FLAG_DO    (1<<RES_DO)
192 #define FLAG_DONE  (1<<RES_DONE)
193 #define FLAG_IN    (1<<RES_IN)
194 #define FLAG_START (1<<RES_XXXX)
195 
196 /* This holds pointers to the various results of parsing */
197 struct p_context {
198 	struct child_prog *child;
199 	struct pipe *list_head;
200 	struct pipe *pipe;
201 #ifndef __U_BOOT__
202 	struct redir_struct *pending_redirect;
203 #endif
204 	reserved_style w;
205 	int old_flag;				/* for figuring out valid reserved words */
206 	struct p_context *stack;
207 	int type;			/* define type of parser : ";$" common or special symbol */
208 	/* How about quoting status? */
209 };
210 
211 #ifndef __U_BOOT__
212 struct redir_struct {
213 	redir_type type;			/* type of redirection */
214 	int fd;						/* file descriptor being redirected */
215 	int dup;					/* -1, or file descriptor being duplicated */
216 	struct redir_struct *next;	/* pointer to the next redirect in the list */
217 	glob_t word;				/* *word.gl_pathv is the filename */
218 };
219 #endif
220 
221 struct child_prog {
222 #ifndef __U_BOOT__
223 	pid_t pid;					/* 0 if exited */
224 #endif
225 	char **argv;				/* program name and arguments */
226 	/* was quoted when parsed; copy of struct o_string.nonnull field */
227 	int *argv_nonnull;
228 #ifdef __U_BOOT__
229 	int    argc;                            /* number of program arguments */
230 #endif
231 	struct pipe *group;			/* if non-NULL, first in group or subshell */
232 #ifndef __U_BOOT__
233 	int subshell;				/* flag, non-zero if group must be forked */
234 	struct redir_struct *redirects;	/* I/O redirections */
235 	glob_t glob_result;			/* result of parameter globbing */
236 	int is_stopped;				/* is the program currently running? */
237 	struct pipe *family;		/* pointer back to the child's parent pipe */
238 #endif
239 	int sp;				/* number of SPECIAL_VAR_SYMBOL */
240 	int type;
241 };
242 
243 struct pipe {
244 #ifndef __U_BOOT__
245 	int jobid;					/* job number */
246 #endif
247 	int num_progs;				/* total number of programs in job */
248 #ifndef __U_BOOT__
249 	int running_progs;			/* number of programs running */
250 	char *text;					/* name of job */
251 	char *cmdbuf;				/* buffer various argv's point into */
252 	pid_t pgrp;					/* process group ID for the job */
253 #endif
254 	struct child_prog *progs;	/* array of commands in pipe */
255 	struct pipe *next;			/* to track background commands */
256 #ifndef __U_BOOT__
257 	int stopped_progs;			/* number of programs alive, but stopped */
258 	int job_context;			/* bitmask defining current context */
259 #endif
260 	pipe_style followup;		/* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
261 	reserved_style r_mode;		/* supports if, for, while, until */
262 };
263 
264 #ifndef __U_BOOT__
265 struct close_me {
266 	int fd;
267 	struct close_me *next;
268 };
269 #endif
270 
271 struct variables {
272 	char *name;
273 	char *value;
274 	int flg_export;
275 	int flg_read_only;
276 	struct variables *next;
277 };
278 
279 /* globals, connect us to the outside world
280  * the first three support $?, $#, and $1 */
281 #ifndef __U_BOOT__
282 char **global_argv;
283 unsigned int global_argc;
284 #endif
285 static unsigned int last_return_code;
286 #ifndef __U_BOOT__
287 extern char **environ; /* This is in <unistd.h>, but protected with __USE_GNU */
288 #endif
289 
290 /* "globals" within this file */
291 static uchar *ifs;
292 static char map[256];
293 #ifndef __U_BOOT__
294 static int fake_mode;
295 static int interactive;
296 static struct close_me *close_me_head;
297 static const char *cwd;
298 static struct pipe *job_list;
299 static unsigned int last_bg_pid;
300 static unsigned int last_jobid;
301 static unsigned int shell_terminal;
302 static char *PS1;
303 static char *PS2;
304 struct variables shell_ver = { "HUSH_VERSION", "0.01", 1, 1, 0 };
305 struct variables *top_vars = &shell_ver;
306 #else
307 static int flag_repeat = 0;
308 static int do_repeat = 0;
309 static struct variables *top_vars = NULL ;
310 #endif /*__U_BOOT__ */
311 
312 #define B_CHUNK (100)
313 #define B_NOSPAC 1
314 
315 typedef struct {
316 	char *data;
317 	int length;
318 	int maxlen;
319 	int quote;
320 	int nonnull;
321 } o_string;
322 #define NULL_O_STRING {NULL,0,0,0,0}
323 /* used for initialization:
324 	o_string foo = NULL_O_STRING; */
325 
326 /* I can almost use ordinary FILE *.  Is open_memstream() universally
327  * available?  Where is it documented? */
328 struct in_str {
329 	const char *p;
330 #ifndef __U_BOOT__
331 	char peek_buf[2];
332 #endif
333 	int __promptme;
334 	int promptmode;
335 #ifndef __U_BOOT__
336 	FILE *file;
337 #endif
338 	int (*get) (struct in_str *);
339 	int (*peek) (struct in_str *);
340 };
341 #define b_getch(input) ((input)->get(input))
342 #define b_peek(input) ((input)->peek(input))
343 
344 #ifndef __U_BOOT__
345 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
346 
347 struct built_in_command {
348 	char *cmd;					/* name */
349 	char *descr;				/* description */
350 	int (*function) (struct child_prog *);	/* function ptr */
351 };
352 #endif
353 
354 /* define DEBUG_SHELL for debugging output (obviously ;-)) */
355 #if 0
356 #define DEBUG_SHELL
357 #endif
358 
359 /* This should be in utility.c */
360 #ifdef DEBUG_SHELL
361 #ifndef __U_BOOT__
debug_printf(const char * format,...)362 static void debug_printf(const char *format, ...)
363 {
364 	va_list args;
365 	va_start(args, format);
366 	vfprintf(stderr, format, args);
367 	va_end(args);
368 }
369 #else
370 #define debug_printf(fmt,args...)	printf (fmt ,##args)
371 #endif
372 #else
debug_printf(const char * format,...)373 static inline void debug_printf(const char *format, ...) { }
374 #endif
375 #define final_printf debug_printf
376 
377 #ifdef __U_BOOT__
syntax_err(void)378 static void syntax_err(void) {
379 	 printf("syntax error\n");
380 }
381 #else
__syntax(char * file,int line)382 static void __syntax(char *file, int line) {
383 	error_msg("syntax error %s:%d", file, line);
384 }
385 #define syntax() __syntax(__FILE__, __LINE__)
386 #endif
387 
388 #ifdef __U_BOOT__
389 static void *xmalloc(size_t size);
390 static void *xrealloc(void *ptr, size_t size);
391 #else
392 /* Index of subroutines: */
393 /*   function prototypes for builtins */
394 static int builtin_cd(struct child_prog *child);
395 static int builtin_env(struct child_prog *child);
396 static int builtin_eval(struct child_prog *child);
397 static int builtin_exec(struct child_prog *child);
398 static int builtin_exit(struct child_prog *child);
399 static int builtin_export(struct child_prog *child);
400 static int builtin_fg_bg(struct child_prog *child);
401 static int builtin_help(struct child_prog *child);
402 static int builtin_jobs(struct child_prog *child);
403 static int builtin_pwd(struct child_prog *child);
404 static int builtin_read(struct child_prog *child);
405 static int builtin_set(struct child_prog *child);
406 static int builtin_shift(struct child_prog *child);
407 static int builtin_source(struct child_prog *child);
408 static int builtin_umask(struct child_prog *child);
409 static int builtin_unset(struct child_prog *child);
410 static int builtin_not_written(struct child_prog *child);
411 #endif
412 /*   o_string manipulation: */
413 static int b_check_space(o_string *o, int len);
414 static int b_addchr(o_string *o, int ch);
415 static void b_reset(o_string *o);
416 static int b_addqchr(o_string *o, int ch, int quote);
417 #ifndef __U_BOOT__
418 static int b_adduint(o_string *o, unsigned int i);
419 #endif
420 /*  in_str manipulations: */
421 static int static_get(struct in_str *i);
422 static int static_peek(struct in_str *i);
423 static int file_get(struct in_str *i);
424 static int file_peek(struct in_str *i);
425 #ifndef __U_BOOT__
426 static void setup_file_in_str(struct in_str *i, FILE *f);
427 #else
428 static void setup_file_in_str(struct in_str *i);
429 #endif
430 static void setup_string_in_str(struct in_str *i, const char *s);
431 #ifndef __U_BOOT__
432 /*  close_me manipulations: */
433 static void mark_open(int fd);
434 static void mark_closed(int fd);
435 static void close_all(void);
436 #endif
437 /*  "run" the final data structures: */
438 static char *indenter(int i);
439 static int free_pipe_list(struct pipe *head, int indent);
440 static int free_pipe(struct pipe *pi, int indent);
441 /*  really run the final data structures: */
442 #ifndef __U_BOOT__
443 static int setup_redirects(struct child_prog *prog, int squirrel[]);
444 #endif
445 static int run_list_real(struct pipe *pi);
446 #ifndef __U_BOOT__
447 static void pseudo_exec(struct child_prog *child) __attribute__ ((noreturn));
448 #endif
449 static int run_pipe_real(struct pipe *pi);
450 /*   extended glob support: */
451 #ifndef __U_BOOT__
452 static int globhack(const char *src, int flags, glob_t *pglob);
453 static int glob_needed(const char *s);
454 static int xglob(o_string *dest, int flags, glob_t *pglob);
455 #endif
456 /*   variable assignment: */
457 static int is_assignment(const char *s);
458 /*   data structure manipulation: */
459 #ifndef __U_BOOT__
460 static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
461 #endif
462 static void initialize_context(struct p_context *ctx);
463 static int done_word(o_string *dest, struct p_context *ctx);
464 static int done_command(struct p_context *ctx);
465 static int done_pipe(struct p_context *ctx, pipe_style type);
466 /*   primary string parsing: */
467 #ifndef __U_BOOT__
468 static int redirect_dup_num(struct in_str *input);
469 static int redirect_opt_num(o_string *o);
470 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end);
471 static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch);
472 #endif
473 static char *lookup_param(char *src);
474 static char *make_string(char **inp, int *nonnull);
475 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input);
476 #ifndef __U_BOOT__
477 static int parse_string(o_string *dest, struct p_context *ctx, const char *src);
478 #endif
479 static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, int end_trigger);
480 /*   setup: */
481 static int parse_stream_outer(struct in_str *inp, int flag);
482 #ifndef __U_BOOT__
483 static int parse_string_outer(const char *s, int flag);
484 static int parse_file_outer(FILE *f);
485 #endif
486 #ifndef __U_BOOT__
487 /*   job management: */
488 static int checkjobs(struct pipe* fg_pipe);
489 static void insert_bg_job(struct pipe *pi);
490 static void remove_bg_job(struct pipe *pi);
491 #endif
492 /*     local variable support */
493 static char **make_list_in(char **inp, char *name);
494 static char *insert_var_value(char *inp);
495 static char *insert_var_value_sub(char *inp, int tag_subst);
496 
497 #ifndef __U_BOOT__
498 /* Table of built-in functions.  They can be forked or not, depending on
499  * context: within pipes, they fork.  As simple commands, they do not.
500  * When used in non-forking context, they can change global variables
501  * in the parent shell process.  If forked, of course they can not.
502  * For example, 'unset foo | whatever' will parse and run, but foo will
503  * still be set at the end. */
504 static struct built_in_command bltins[] = {
505 	{"bg", "Resume a job in the background", builtin_fg_bg},
506 	{"break", "Exit for, while or until loop", builtin_not_written},
507 	{"cd", "Change working directory", builtin_cd},
508 	{"continue", "Continue for, while or until loop", builtin_not_written},
509 	{"env", "Print all environment variables", builtin_env},
510 	{"eval", "Construct and run shell command", builtin_eval},
511 	{"exec", "Exec command, replacing this shell with the exec'd process",
512 		builtin_exec},
513 	{"exit", "Exit from shell()", builtin_exit},
514 	{"export", "Set environment variable", builtin_export},
515 	{"fg", "Bring job into the foreground", builtin_fg_bg},
516 	{"jobs", "Lists the active jobs", builtin_jobs},
517 	{"pwd", "Print current directory", builtin_pwd},
518 	{"read", "Input environment variable", builtin_read},
519 	{"return", "Return from a function", builtin_not_written},
520 	{"set", "Set/unset shell local variables", builtin_set},
521 	{"shift", "Shift positional parameters", builtin_shift},
522 	{"trap", "Trap signals", builtin_not_written},
523 	{"ulimit","Controls resource limits", builtin_not_written},
524 	{"umask","Sets file creation mask", builtin_umask},
525 	{"unset", "Unset environment variable", builtin_unset},
526 	{".", "Source-in and run commands in a file", builtin_source},
527 	{"help", "List shell built-in commands", builtin_help},
528 	{NULL, NULL, NULL}
529 };
530 
set_cwd(void)531 static const char *set_cwd(void)
532 {
533 	if(cwd==unknown)
534 		cwd = NULL;     /* xgetcwd(arg) called free(arg) */
535 	cwd = xgetcwd((char *)cwd);
536 	if (!cwd)
537 		cwd = unknown;
538 	return cwd;
539 }
540 
541 /* built-in 'eval' handler */
builtin_eval(struct child_prog * child)542 static int builtin_eval(struct child_prog *child)
543 {
544 	char *str = NULL;
545 	int rcode = EXIT_SUCCESS;
546 
547 	if (child->argv[1]) {
548 		str = make_string(child->argv + 1);
549 		parse_string_outer(str, FLAG_EXIT_FROM_LOOP |
550 					FLAG_PARSE_SEMICOLON);
551 		free(str);
552 		rcode = last_return_code;
553 	}
554 	return rcode;
555 }
556 
557 /* built-in 'cd <path>' handler */
builtin_cd(struct child_prog * child)558 static int builtin_cd(struct child_prog *child)
559 {
560 	char *newdir;
561 	if (child->argv[1] == NULL)
562 		newdir = env_get("HOME");
563 	else
564 		newdir = child->argv[1];
565 	if (chdir(newdir)) {
566 		printf("cd: %s: %s\n", newdir, strerror(errno));
567 		return EXIT_FAILURE;
568 	}
569 	set_cwd();
570 	return EXIT_SUCCESS;
571 }
572 
573 /* built-in 'env' handler */
builtin_env(struct child_prog * dummy)574 static int builtin_env(struct child_prog *dummy)
575 {
576 	char **e = environ;
577 	if (e == NULL) return EXIT_FAILURE;
578 	for (; *e; e++) {
579 		puts(*e);
580 	}
581 	return EXIT_SUCCESS;
582 }
583 
584 /* built-in 'exec' handler */
builtin_exec(struct child_prog * child)585 static int builtin_exec(struct child_prog *child)
586 {
587 	if (child->argv[1] == NULL)
588 		return EXIT_SUCCESS;   /* Really? */
589 	child->argv++;
590 	pseudo_exec(child);
591 	/* never returns */
592 }
593 
594 /* built-in 'exit' handler */
builtin_exit(struct child_prog * child)595 static int builtin_exit(struct child_prog *child)
596 {
597 	if (child->argv[1] == NULL)
598 		exit(last_return_code);
599 	exit (atoi(child->argv[1]));
600 }
601 
602 /* built-in 'export VAR=value' handler */
builtin_export(struct child_prog * child)603 static int builtin_export(struct child_prog *child)
604 {
605 	int res = 0;
606 	char *name = child->argv[1];
607 
608 	if (name == NULL) {
609 		return (builtin_env(child));
610 	}
611 
612 	name = strdup(name);
613 
614 	if(name) {
615 		char *value = strchr(name, '=');
616 
617 		if (!value) {
618 			char *tmp;
619 			/* They are exporting something without an =VALUE */
620 
621 			value = get_local_var(name);
622 			if (value) {
623 				size_t ln = strlen(name);
624 
625 				tmp = realloc(name, ln+strlen(value)+2);
626 				if(tmp==NULL)
627 					res = -1;
628 				else {
629 					sprintf(tmp+ln, "=%s", value);
630 					name = tmp;
631 				}
632 			} else {
633 				/* bash does not return an error when trying to export
634 				 * an undefined variable.  Do likewise. */
635 				res = 1;
636 			}
637 		}
638 	}
639 	if (res<0)
640 		perror_msg("export");
641 	else if(res==0)
642 		res = set_local_var(name, 1);
643 	else
644 		res = 0;
645 	free(name);
646 	return res;
647 }
648 
649 /* built-in 'fg' and 'bg' handler */
builtin_fg_bg(struct child_prog * child)650 static int builtin_fg_bg(struct child_prog *child)
651 {
652 	int i, jobnum;
653 	struct pipe *pi=NULL;
654 
655 	if (!interactive)
656 		return EXIT_FAILURE;
657 	/* If they gave us no args, assume they want the last backgrounded task */
658 	if (!child->argv[1]) {
659 		for (pi = job_list; pi; pi = pi->next) {
660 			if (pi->jobid == last_jobid) {
661 				break;
662 			}
663 		}
664 		if (!pi) {
665 			error_msg("%s: no current job", child->argv[0]);
666 			return EXIT_FAILURE;
667 		}
668 	} else {
669 		if (sscanf(child->argv[1], "%%%d", &jobnum) != 1) {
670 			error_msg("%s: bad argument '%s'", child->argv[0], child->argv[1]);
671 			return EXIT_FAILURE;
672 		}
673 		for (pi = job_list; pi; pi = pi->next) {
674 			if (pi->jobid == jobnum) {
675 				break;
676 			}
677 		}
678 		if (!pi) {
679 			error_msg("%s: %d: no such job", child->argv[0], jobnum);
680 			return EXIT_FAILURE;
681 		}
682 	}
683 
684 	if (*child->argv[0] == 'f') {
685 		/* Put the job into the foreground.  */
686 		tcsetpgrp(shell_terminal, pi->pgrp);
687 	}
688 
689 	/* Restart the processes in the job */
690 	for (i = 0; i < pi->num_progs; i++)
691 		pi->progs[i].is_stopped = 0;
692 
693 	if ( (i=kill(- pi->pgrp, SIGCONT)) < 0) {
694 		if (i == ESRCH) {
695 			remove_bg_job(pi);
696 		} else {
697 			perror_msg("kill (SIGCONT)");
698 		}
699 	}
700 
701 	pi->stopped_progs = 0;
702 	return EXIT_SUCCESS;
703 }
704 
705 /* built-in 'help' handler */
builtin_help(struct child_prog * dummy)706 static int builtin_help(struct child_prog *dummy)
707 {
708 	struct built_in_command *x;
709 
710 	printf("\nBuilt-in commands:\n");
711 	printf("-------------------\n");
712 	for (x = bltins; x->cmd; x++) {
713 		if (x->descr==NULL)
714 			continue;
715 		printf("%s\t%s\n", x->cmd, x->descr);
716 	}
717 	printf("\n\n");
718 	return EXIT_SUCCESS;
719 }
720 
721 /* built-in 'jobs' handler */
builtin_jobs(struct child_prog * child)722 static int builtin_jobs(struct child_prog *child)
723 {
724 	struct pipe *job;
725 	char *status_string;
726 
727 	for (job = job_list; job; job = job->next) {
728 		if (job->running_progs == job->stopped_progs)
729 			status_string = "Stopped";
730 		else
731 			status_string = "Running";
732 
733 		printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->text);
734 	}
735 	return EXIT_SUCCESS;
736 }
737 
738 
739 /* built-in 'pwd' handler */
builtin_pwd(struct child_prog * dummy)740 static int builtin_pwd(struct child_prog *dummy)
741 {
742 	puts(set_cwd());
743 	return EXIT_SUCCESS;
744 }
745 
746 /* built-in 'read VAR' handler */
builtin_read(struct child_prog * child)747 static int builtin_read(struct child_prog *child)
748 {
749 	int res;
750 
751 	if (child->argv[1]) {
752 		char string[BUFSIZ];
753 		char *var = 0;
754 
755 		string[0] = 0;  /* In case stdin has only EOF */
756 		/* read string */
757 		fgets(string, sizeof(string), stdin);
758 		chomp(string);
759 		var = malloc(strlen(child->argv[1])+strlen(string)+2);
760 		if(var) {
761 			sprintf(var, "%s=%s", child->argv[1], string);
762 			res = set_local_var(var, 0);
763 		} else
764 			res = -1;
765 		if (res)
766 			fprintf(stderr, "read: %m\n");
767 		free(var);      /* So not move up to avoid breaking errno */
768 		return res;
769 	} else {
770 		do res=getchar(); while(res!='\n' && res!=EOF);
771 		return 0;
772 	}
773 }
774 
775 /* built-in 'set VAR=value' handler */
builtin_set(struct child_prog * child)776 static int builtin_set(struct child_prog *child)
777 {
778 	char *temp = child->argv[1];
779 	struct variables *e;
780 
781 	if (temp == NULL)
782 		for(e = top_vars; e; e=e->next)
783 			printf("%s=%s\n", e->name, e->value);
784 	else
785 		set_local_var(temp, 0);
786 
787 		return EXIT_SUCCESS;
788 }
789 
790 
791 /* Built-in 'shift' handler */
builtin_shift(struct child_prog * child)792 static int builtin_shift(struct child_prog *child)
793 {
794 	int n=1;
795 	if (child->argv[1]) {
796 		n=atoi(child->argv[1]);
797 	}
798 	if (n>=0 && n<global_argc) {
799 		/* XXX This probably breaks $0 */
800 		global_argc -= n;
801 		global_argv += n;
802 		return EXIT_SUCCESS;
803 	} else {
804 		return EXIT_FAILURE;
805 	}
806 }
807 
808 /* Built-in '.' handler (read-in and execute commands from file) */
builtin_source(struct child_prog * child)809 static int builtin_source(struct child_prog *child)
810 {
811 	FILE *input;
812 	int status;
813 
814 	if (child->argv[1] == NULL)
815 		return EXIT_FAILURE;
816 
817 	/* XXX search through $PATH is missing */
818 	input = fopen(child->argv[1], "r");
819 	if (!input) {
820 		error_msg("Couldn't open file '%s'", child->argv[1]);
821 		return EXIT_FAILURE;
822 	}
823 
824 	/* Now run the file */
825 	/* XXX argv and argc are broken; need to save old global_argv
826 	 * (pointer only is OK!) on this stack frame,
827 	 * set global_argv=child->argv+1, recurse, and restore. */
828 	mark_open(fileno(input));
829 	status = parse_file_outer(input);
830 	mark_closed(fileno(input));
831 	fclose(input);
832 	return (status);
833 }
834 
builtin_umask(struct child_prog * child)835 static int builtin_umask(struct child_prog *child)
836 {
837 	mode_t new_umask;
838 	const char *arg = child->argv[1];
839 	char *end;
840 	if (arg) {
841 		new_umask=strtoul(arg, &end, 8);
842 		if (*end!='\0' || end == arg) {
843 			return EXIT_FAILURE;
844 		}
845 	} else {
846 		printf("%.3o\n", (unsigned int) (new_umask=umask(0)));
847 	}
848 	umask(new_umask);
849 	return EXIT_SUCCESS;
850 }
851 
852 /* built-in 'unset VAR' handler */
builtin_unset(struct child_prog * child)853 static int builtin_unset(struct child_prog *child)
854 {
855 	/* bash returned already true */
856 	unset_local_var(child->argv[1]);
857 	return EXIT_SUCCESS;
858 }
859 
builtin_not_written(struct child_prog * child)860 static int builtin_not_written(struct child_prog *child)
861 {
862 	printf("builtin_%s not written\n",child->argv[0]);
863 	return EXIT_FAILURE;
864 }
865 #endif
866 
b_check_space(o_string * o,int len)867 static int b_check_space(o_string *o, int len)
868 {
869 	/* It would be easy to drop a more restrictive policy
870 	 * in here, such as setting a maximum string length */
871 	if (o->length + len > o->maxlen) {
872 		char *old_data = o->data;
873 		/* assert (data == NULL || o->maxlen != 0); */
874 		o->maxlen += max(2*len, B_CHUNK);
875 		o->data = realloc(o->data, 1 + o->maxlen);
876 		if (o->data == NULL) {
877 			free(old_data);
878 		}
879 	}
880 	return o->data == NULL;
881 }
882 
b_addchr(o_string * o,int ch)883 static int b_addchr(o_string *o, int ch)
884 {
885 	debug_printf("b_addchr: %c %d %p\n", ch, o->length, o);
886 	if (b_check_space(o, 1)) return B_NOSPAC;
887 	o->data[o->length] = ch;
888 	o->length++;
889 	o->data[o->length] = '\0';
890 	return 0;
891 }
892 
b_reset(o_string * o)893 static void b_reset(o_string *o)
894 {
895 	o->length = 0;
896 	o->nonnull = 0;
897 	if (o->data != NULL) *o->data = '\0';
898 }
899 
b_free(o_string * o)900 static void b_free(o_string *o)
901 {
902 	b_reset(o);
903 	free(o->data);
904 	o->data = NULL;
905 	o->maxlen = 0;
906 }
907 
908 /* My analysis of quoting semantics tells me that state information
909  * is associated with a destination, not a source.
910  */
b_addqchr(o_string * o,int ch,int quote)911 static int b_addqchr(o_string *o, int ch, int quote)
912 {
913 	if (quote && strchr("*?[\\",ch)) {
914 		int rc;
915 		rc = b_addchr(o, '\\');
916 		if (rc) return rc;
917 	}
918 	return b_addchr(o, ch);
919 }
920 
921 #ifndef __U_BOOT__
b_adduint(o_string * o,unsigned int i)922 static int b_adduint(o_string *o, unsigned int i)
923 {
924 	int r;
925 	char *p = simple_itoa(i);
926 	/* no escape checking necessary */
927 	do r=b_addchr(o, *p++); while (r==0 && *p);
928 	return r;
929 }
930 #endif
931 
static_get(struct in_str * i)932 static int static_get(struct in_str *i)
933 {
934 	int ch = *i->p++;
935 	if (ch=='\0') return EOF;
936 	return ch;
937 }
938 
static_peek(struct in_str * i)939 static int static_peek(struct in_str *i)
940 {
941 	return *i->p;
942 }
943 
944 #ifndef __U_BOOT__
cmdedit_set_initial_prompt(void)945 static inline void cmdedit_set_initial_prompt(void)
946 {
947 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
948 	PS1 = NULL;
949 #else
950 	PS1 = env_get("PS1");
951 	if(PS1==0)
952 		PS1 = "\\w \\$ ";
953 #endif
954 }
955 
setup_prompt_string(int promptmode,char ** prompt_str)956 static inline void setup_prompt_string(int promptmode, char **prompt_str)
957 {
958 	debug_printf("setup_prompt_string %d ",promptmode);
959 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
960 	/* Set up the prompt */
961 	if (promptmode == 1) {
962 		free(PS1);
963 		PS1=xmalloc(strlen(cwd)+4);
964 		sprintf(PS1, "%s %s", cwd, ( geteuid() != 0 ) ?  "$ ":"# ");
965 		*prompt_str = PS1;
966 	} else {
967 		*prompt_str = PS2;
968 	}
969 #else
970 	*prompt_str = (promptmode==1)? PS1 : PS2;
971 #endif
972 	debug_printf("result %s\n",*prompt_str);
973 }
974 #endif
975 
976 #ifdef __U_BOOT__
uboot_cli_readline(struct in_str * i)977 static int uboot_cli_readline(struct in_str *i)
978 {
979 	char *prompt;
980 	char __maybe_unused *ps_prompt = NULL;
981 
982 	if (i->promptmode == 1)
983 		prompt = CONFIG_SYS_PROMPT;
984 	else
985 		prompt = CONFIG_SYS_PROMPT_HUSH_PS2;
986 
987 #ifdef CONFIG_CMDLINE_PS_SUPPORT
988 	if (i->promptmode == 1)
989 		ps_prompt = env_get("PS1");
990 	else
991 		ps_prompt = env_get("PS2");
992 	if (ps_prompt)
993 		prompt = ps_prompt;
994 #endif
995 
996 	return cli_readline(prompt);
997 }
998 #endif
999 
get_user_input(struct in_str * i)1000 static void get_user_input(struct in_str *i)
1001 {
1002 #ifndef __U_BOOT__
1003 	char *prompt_str;
1004 	static char the_command[BUFSIZ];
1005 
1006 	setup_prompt_string(i->promptmode, &prompt_str);
1007 #ifdef CONFIG_FEATURE_COMMAND_EDITING
1008 	/*
1009 	 ** enable command line editing only while a command line
1010 	 ** is actually being read; otherwise, we'll end up bequeathing
1011 	 ** atexit() handlers and other unwanted stuff to our
1012 	 ** child processes (rob@sysgo.de)
1013 	 */
1014 	cmdedit_read_input(prompt_str, the_command);
1015 #else
1016 	fputs(prompt_str, stdout);
1017 	fflush(stdout);
1018 	the_command[0]=fgetc(i->file);
1019 	the_command[1]='\0';
1020 #endif
1021 	fflush(stdout);
1022 	i->p = the_command;
1023 #else
1024 	int n;
1025 	static char the_command[CONFIG_SYS_CBSIZE + 1];
1026 
1027 	bootretry_reset_cmd_timeout();
1028 	i->__promptme = 1;
1029 	n = uboot_cli_readline(i);
1030 
1031 #ifdef CONFIG_BOOT_RETRY_TIME
1032 	if (n == -2) {
1033 	  puts("\nTimeout waiting for command\n");
1034 #  ifdef CONFIG_RESET_TO_RETRY
1035 	  do_reset(NULL, 0, 0, NULL);
1036 #  else
1037 #	error "This currently only works with CONFIG_RESET_TO_RETRY enabled"
1038 #  endif
1039 	}
1040 #endif
1041 	if (n == -1 ) {
1042 		flag_repeat = 0;
1043 		i->__promptme = 0;
1044 	}
1045 	n = strlen(console_buffer);
1046 	console_buffer[n] = '\n';
1047 	console_buffer[n+1]= '\0';
1048 	if (had_ctrlc()) flag_repeat = 0;
1049 	clear_ctrlc();
1050 	do_repeat = 0;
1051 	if (i->promptmode == 1) {
1052 		if (console_buffer[0] == '\n'&& flag_repeat == 0) {
1053 			strcpy(the_command,console_buffer);
1054 		}
1055 		else {
1056 			if (console_buffer[0] != '\n') {
1057 				strcpy(the_command,console_buffer);
1058 				flag_repeat = 1;
1059 			}
1060 			else {
1061 				do_repeat = 1;
1062 			}
1063 		}
1064 		i->p = the_command;
1065 	}
1066 	else {
1067 		if (console_buffer[0] != '\n') {
1068 			if (strlen(the_command) + strlen(console_buffer)
1069 			    < CONFIG_SYS_CBSIZE) {
1070 				n = strlen(the_command);
1071 				the_command[n-1] = ' ';
1072 				strcpy(&the_command[n],console_buffer);
1073 			}
1074 			else {
1075 				the_command[0] = '\n';
1076 				the_command[1] = '\0';
1077 				flag_repeat = 0;
1078 			}
1079 		}
1080 		if (i->__promptme == 0) {
1081 			the_command[0] = '\n';
1082 			the_command[1] = '\0';
1083 		}
1084 		i->p = console_buffer;
1085 	}
1086 #endif
1087 }
1088 
1089 /* This is the magic location that prints prompts
1090  * and gets data back from the user */
file_get(struct in_str * i)1091 static int file_get(struct in_str *i)
1092 {
1093 	int ch;
1094 
1095 	ch = 0;
1096 	/* If there is data waiting, eat it up */
1097 	if (i->p && *i->p) {
1098 		ch = *i->p++;
1099 	} else {
1100 		/* need to double check i->file because we might be doing something
1101 		 * more complicated by now, like sourcing or substituting. */
1102 #ifndef __U_BOOT__
1103 		if (i->__promptme && interactive && i->file == stdin) {
1104 			while(! i->p || (interactive && strlen(i->p)==0) ) {
1105 #else
1106 			while(! i->p  || strlen(i->p)==0 ) {
1107 #endif
1108 				get_user_input(i);
1109 			}
1110 			i->promptmode=2;
1111 #ifndef __U_BOOT__
1112 			i->__promptme = 0;
1113 #endif
1114 			if (i->p && *i->p) {
1115 				ch = *i->p++;
1116 			}
1117 #ifndef __U_BOOT__
1118 		} else {
1119 			ch = fgetc(i->file);
1120 		}
1121 
1122 #endif
1123 		debug_printf("b_getch: got a %d\n", ch);
1124 	}
1125 #ifndef __U_BOOT__
1126 	if (ch == '\n') i->__promptme=1;
1127 #endif
1128 	return ch;
1129 }
1130 
1131 /* All the callers guarantee this routine will never be
1132  * used right after a newline, so prompting is not needed.
1133  */
1134 static int file_peek(struct in_str *i)
1135 {
1136 #ifndef __U_BOOT__
1137 	if (i->p && *i->p) {
1138 #endif
1139 		return *i->p;
1140 #ifndef __U_BOOT__
1141 	} else {
1142 		i->peek_buf[0] = fgetc(i->file);
1143 		i->peek_buf[1] = '\0';
1144 		i->p = i->peek_buf;
1145 		debug_printf("b_peek: got a %d\n", *i->p);
1146 		return *i->p;
1147 	}
1148 #endif
1149 }
1150 
1151 #ifndef __U_BOOT__
1152 static void setup_file_in_str(struct in_str *i, FILE *f)
1153 #else
1154 static void setup_file_in_str(struct in_str *i)
1155 #endif
1156 {
1157 	i->peek = file_peek;
1158 	i->get = file_get;
1159 	i->__promptme=1;
1160 	i->promptmode=1;
1161 #ifndef __U_BOOT__
1162 	i->file = f;
1163 #endif
1164 	i->p = NULL;
1165 }
1166 
1167 static void setup_string_in_str(struct in_str *i, const char *s)
1168 {
1169 	i->peek = static_peek;
1170 	i->get = static_get;
1171 	i->__promptme=1;
1172 	i->promptmode=1;
1173 	i->p = s;
1174 }
1175 
1176 #ifndef __U_BOOT__
1177 static void mark_open(int fd)
1178 {
1179 	struct close_me *new = xmalloc(sizeof(struct close_me));
1180 	new->fd = fd;
1181 	new->next = close_me_head;
1182 	close_me_head = new;
1183 }
1184 
1185 static void mark_closed(int fd)
1186 {
1187 	struct close_me *tmp;
1188 	if (close_me_head == NULL || close_me_head->fd != fd)
1189 		error_msg_and_die("corrupt close_me");
1190 	tmp = close_me_head;
1191 	close_me_head = close_me_head->next;
1192 	free(tmp);
1193 }
1194 
1195 static void close_all(void)
1196 {
1197 	struct close_me *c;
1198 	for (c=close_me_head; c; c=c->next) {
1199 		close(c->fd);
1200 	}
1201 	close_me_head = NULL;
1202 }
1203 
1204 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
1205  * and stderr if they are redirected. */
1206 static int setup_redirects(struct child_prog *prog, int squirrel[])
1207 {
1208 	int openfd, mode;
1209 	struct redir_struct *redir;
1210 
1211 	for (redir=prog->redirects; redir; redir=redir->next) {
1212 		if (redir->dup == -1 && redir->word.gl_pathv == NULL) {
1213 			/* something went wrong in the parse.  Pretend it didn't happen */
1214 			continue;
1215 		}
1216 		if (redir->dup == -1) {
1217 			mode=redir_table[redir->type].mode;
1218 			openfd = open(redir->word.gl_pathv[0], mode, 0666);
1219 			if (openfd < 0) {
1220 			/* this could get lost if stderr has been redirected, but
1221 			   bash and ash both lose it as well (though zsh doesn't!) */
1222 				perror_msg("error opening %s", redir->word.gl_pathv[0]);
1223 				return 1;
1224 			}
1225 		} else {
1226 			openfd = redir->dup;
1227 		}
1228 
1229 		if (openfd != redir->fd) {
1230 			if (squirrel && redir->fd < 3) {
1231 				squirrel[redir->fd] = dup(redir->fd);
1232 			}
1233 			if (openfd == -3) {
1234 				close(openfd);
1235 			} else {
1236 				dup2(openfd, redir->fd);
1237 				if (redir->dup == -1)
1238 					close (openfd);
1239 			}
1240 		}
1241 	}
1242 	return 0;
1243 }
1244 
1245 static void restore_redirects(int squirrel[])
1246 {
1247 	int i, fd;
1248 	for (i=0; i<3; i++) {
1249 		fd = squirrel[i];
1250 		if (fd != -1) {
1251 			/* No error checking.  I sure wouldn't know what
1252 			 * to do with an error if I found one! */
1253 			dup2(fd, i);
1254 			close(fd);
1255 		}
1256 	}
1257 }
1258 
1259 /* never returns */
1260 /* XXX no exit() here.  If you don't exec, use _exit instead.
1261  * The at_exit handlers apparently confuse the calling process,
1262  * in particular stdin handling.  Not sure why? */
1263 static void pseudo_exec(struct child_prog *child)
1264 {
1265 	int i, rcode;
1266 	char *p;
1267 	struct built_in_command *x;
1268 	if (child->argv) {
1269 		for (i=0; is_assignment(child->argv[i]); i++) {
1270 			debug_printf("pid %d environment modification: %s\n",getpid(),child->argv[i]);
1271 			p = insert_var_value(child->argv[i]);
1272 			putenv(strdup(p));
1273 			if (p != child->argv[i]) free(p);
1274 		}
1275 		child->argv+=i;  /* XXX this hack isn't so horrible, since we are about
1276 					to exit, and therefore don't need to keep data
1277 					structures consistent for free() use. */
1278 		/* If a variable is assigned in a forest, and nobody listens,
1279 		 * was it ever really set?
1280 		 */
1281 		if (child->argv[0] == NULL) {
1282 			_exit(EXIT_SUCCESS);
1283 		}
1284 
1285 		/*
1286 		 * Check if the command matches any of the builtins.
1287 		 * Depending on context, this might be redundant.  But it's
1288 		 * easier to waste a few CPU cycles than it is to figure out
1289 		 * if this is one of those cases.
1290 		 */
1291 		for (x = bltins; x->cmd; x++) {
1292 			if (strcmp(child->argv[0], x->cmd) == 0 ) {
1293 				debug_printf("builtin exec %s\n", child->argv[0]);
1294 				rcode = x->function(child);
1295 				fflush(stdout);
1296 				_exit(rcode);
1297 			}
1298 		}
1299 
1300 		/* Check if the command matches any busybox internal commands
1301 		 * ("applets") here.
1302 		 * FIXME: This feature is not 100% safe, since
1303 		 * BusyBox is not fully reentrant, so we have no guarantee the things
1304 		 * from the .bss are still zeroed, or that things from .data are still
1305 		 * at their defaults.  We could exec ourself from /proc/self/exe, but I
1306 		 * really dislike relying on /proc for things.  We could exec ourself
1307 		 * from global_argv[0], but if we are in a chroot, we may not be able
1308 		 * to find ourself... */
1309 #ifdef CONFIG_FEATURE_SH_STANDALONE_SHELL
1310 		{
1311 			int argc_l;
1312 			char** argv_l=child->argv;
1313 			char *name = child->argv[0];
1314 
1315 #ifdef CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN
1316 			/* Following discussions from November 2000 on the busybox mailing
1317 			 * list, the default configuration, (without
1318 			 * get_last_path_component()) lets the user force use of an
1319 			 * external command by specifying the full (with slashes) filename.
1320 			 * If you enable CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN then applets
1321 			 * _aways_ override external commands, so if you want to run
1322 			 * /bin/cat, it will use BusyBox cat even if /bin/cat exists on the
1323 			 * filesystem and is _not_ busybox.  Some systems may want this,
1324 			 * most do not.  */
1325 			name = get_last_path_component(name);
1326 #endif
1327 			/* Count argc for use in a second... */
1328 			for(argc_l=0;*argv_l!=NULL; argv_l++, argc_l++);
1329 			optind = 1;
1330 			debug_printf("running applet %s\n", name);
1331 			run_applet_by_name(name, argc_l, child->argv);
1332 		}
1333 #endif
1334 		debug_printf("exec of %s\n",child->argv[0]);
1335 		execvp(child->argv[0],child->argv);
1336 		perror_msg("couldn't exec: %s",child->argv[0]);
1337 		_exit(1);
1338 	} else if (child->group) {
1339 		debug_printf("runtime nesting to group\n");
1340 		interactive=0;    /* crucial!!!! */
1341 		rcode = run_list_real(child->group);
1342 		/* OK to leak memory by not calling free_pipe_list,
1343 		 * since this process is about to exit */
1344 		_exit(rcode);
1345 	} else {
1346 		/* Can happen.  See what bash does with ">foo" by itself. */
1347 		debug_printf("trying to pseudo_exec null command\n");
1348 		_exit(EXIT_SUCCESS);
1349 	}
1350 }
1351 
1352 static void insert_bg_job(struct pipe *pi)
1353 {
1354 	struct pipe *thejob;
1355 
1356 	/* Linear search for the ID of the job to use */
1357 	pi->jobid = 1;
1358 	for (thejob = job_list; thejob; thejob = thejob->next)
1359 		if (thejob->jobid >= pi->jobid)
1360 			pi->jobid = thejob->jobid + 1;
1361 
1362 	/* add thejob to the list of running jobs */
1363 	if (!job_list) {
1364 		thejob = job_list = xmalloc(sizeof(*thejob));
1365 	} else {
1366 		for (thejob = job_list; thejob->next; thejob = thejob->next) /* nothing */;
1367 		thejob->next = xmalloc(sizeof(*thejob));
1368 		thejob = thejob->next;
1369 	}
1370 
1371 	/* physically copy the struct job */
1372 	memcpy(thejob, pi, sizeof(struct pipe));
1373 	thejob->next = NULL;
1374 	thejob->running_progs = thejob->num_progs;
1375 	thejob->stopped_progs = 0;
1376 	thejob->text = xmalloc(BUFSIZ); /* cmdedit buffer size */
1377 
1378 	/*if (pi->progs[0] && pi->progs[0].argv && pi->progs[0].argv[0]) */
1379 	{
1380 		char *bar=thejob->text;
1381 		char **foo=pi->progs[0].argv;
1382 		while(foo && *foo) {
1383 			bar += sprintf(bar, "%s ", *foo++);
1384 		}
1385 	}
1386 
1387 	/* we don't wait for background thejobs to return -- append it
1388 	   to the list of backgrounded thejobs and leave it alone */
1389 	printf("[%d] %d\n", thejob->jobid, thejob->progs[0].pid);
1390 	last_bg_pid = thejob->progs[0].pid;
1391 	last_jobid = thejob->jobid;
1392 }
1393 
1394 /* remove a backgrounded job */
1395 static void remove_bg_job(struct pipe *pi)
1396 {
1397 	struct pipe *prev_pipe;
1398 
1399 	if (pi == job_list) {
1400 		job_list = pi->next;
1401 	} else {
1402 		prev_pipe = job_list;
1403 		while (prev_pipe->next != pi)
1404 			prev_pipe = prev_pipe->next;
1405 		prev_pipe->next = pi->next;
1406 	}
1407 	if (job_list)
1408 		last_jobid = job_list->jobid;
1409 	else
1410 		last_jobid = 0;
1411 
1412 	pi->stopped_progs = 0;
1413 	free_pipe(pi, 0);
1414 	free(pi);
1415 }
1416 
1417 /* Checks to see if any processes have exited -- if they
1418    have, figure out why and see if a job has completed */
1419 static int checkjobs(struct pipe* fg_pipe)
1420 {
1421 	int attributes;
1422 	int status;
1423 	int prognum = 0;
1424 	struct pipe *pi;
1425 	pid_t childpid;
1426 
1427 	attributes = WUNTRACED;
1428 	if (fg_pipe==NULL) {
1429 		attributes |= WNOHANG;
1430 	}
1431 
1432 	while ((childpid = waitpid(-1, &status, attributes)) > 0) {
1433 		if (fg_pipe) {
1434 			int i, rcode = 0;
1435 			for (i=0; i < fg_pipe->num_progs; i++) {
1436 				if (fg_pipe->progs[i].pid == childpid) {
1437 					if (i==fg_pipe->num_progs-1)
1438 						rcode=WEXITSTATUS(status);
1439 					(fg_pipe->num_progs)--;
1440 					return(rcode);
1441 				}
1442 			}
1443 		}
1444 
1445 		for (pi = job_list; pi; pi = pi->next) {
1446 			prognum = 0;
1447 			while (prognum < pi->num_progs && pi->progs[prognum].pid != childpid) {
1448 				prognum++;
1449 			}
1450 			if (prognum < pi->num_progs)
1451 				break;
1452 		}
1453 
1454 		if(pi==NULL) {
1455 			debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
1456 			continue;
1457 		}
1458 
1459 		if (WIFEXITED(status) || WIFSIGNALED(status)) {
1460 			/* child exited */
1461 			pi->running_progs--;
1462 			pi->progs[prognum].pid = 0;
1463 
1464 			if (!pi->running_progs) {
1465 				printf(JOB_STATUS_FORMAT, pi->jobid, "Done", pi->text);
1466 				remove_bg_job(pi);
1467 			}
1468 		} else {
1469 			/* child stopped */
1470 			pi->stopped_progs++;
1471 			pi->progs[prognum].is_stopped = 1;
1472 
1473 #if 0
1474 			/* Printing this stuff is a pain, since it tends to
1475 			 * overwrite the prompt an inconveinient moments.  So
1476 			 * don't do that.  */
1477 			if (pi->stopped_progs == pi->num_progs) {
1478 				printf("\n"JOB_STATUS_FORMAT, pi->jobid, "Stopped", pi->text);
1479 			}
1480 #endif
1481 		}
1482 	}
1483 
1484 	if (childpid == -1 && errno != ECHILD)
1485 		perror_msg("waitpid");
1486 
1487 	/* move the shell to the foreground */
1488 	/*if (interactive && tcsetpgrp(shell_terminal, getpgid(0))) */
1489 	/*	perror_msg("tcsetpgrp-2"); */
1490 	return -1;
1491 }
1492 
1493 /* Figure out our controlling tty, checking in order stderr,
1494  * stdin, and stdout.  If check_pgrp is set, also check that
1495  * we belong to the foreground process group associated with
1496  * that tty.  The value of shell_terminal is needed in order to call
1497  * tcsetpgrp(shell_terminal, ...); */
1498 void controlling_tty(int check_pgrp)
1499 {
1500 	pid_t curpgrp;
1501 
1502 	if ((curpgrp = tcgetpgrp(shell_terminal = 2)) < 0
1503 			&& (curpgrp = tcgetpgrp(shell_terminal = 0)) < 0
1504 			&& (curpgrp = tcgetpgrp(shell_terminal = 1)) < 0)
1505 		goto shell_terminal_error;
1506 
1507 	if (check_pgrp && curpgrp != getpgid(0))
1508 		goto shell_terminal_error;
1509 
1510 	return;
1511 
1512 shell_terminal_error:
1513 		shell_terminal = -1;
1514 		return;
1515 }
1516 #endif
1517 
1518 /* run_pipe_real() starts all the jobs, but doesn't wait for anything
1519  * to finish.  See checkjobs().
1520  *
1521  * return code is normally -1, when the caller has to wait for children
1522  * to finish to determine the exit status of the pipe.  If the pipe
1523  * is a simple builtin command, however, the action is done by the
1524  * time run_pipe_real returns, and the exit code is provided as the
1525  * return value.
1526  *
1527  * The input of the pipe is always stdin, the output is always
1528  * stdout.  The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
1529  * because it tries to avoid running the command substitution in
1530  * subshell, when that is in fact necessary.  The subshell process
1531  * now has its stdout directed to the input of the appropriate pipe,
1532  * so this routine is noticeably simpler.
1533  */
1534 static int run_pipe_real(struct pipe *pi)
1535 {
1536 	int i;
1537 #ifndef __U_BOOT__
1538 	int nextin, nextout;
1539 	int pipefds[2];				/* pipefds[0] is for reading */
1540 	struct child_prog *child;
1541 	struct built_in_command *x;
1542 	char *p;
1543 # if __GNUC__
1544 	/* Avoid longjmp clobbering */
1545 	(void) &i;
1546 	(void) &nextin;
1547 	(void) &nextout;
1548 	(void) &child;
1549 # endif
1550 #else
1551 	int nextin;
1552 	int flag = do_repeat ? CMD_FLAG_REPEAT : 0;
1553 	struct child_prog *child;
1554 	char *p;
1555 # if __GNUC__
1556 	/* Avoid longjmp clobbering */
1557 	(void) &i;
1558 	(void) &nextin;
1559 	(void) &child;
1560 # endif
1561 #endif	/* __U_BOOT__ */
1562 
1563 	nextin = 0;
1564 #ifndef __U_BOOT__
1565 	pi->pgrp = -1;
1566 #endif
1567 
1568 	/* Check if this is a simple builtin (not part of a pipe).
1569 	 * Builtins within pipes have to fork anyway, and are handled in
1570 	 * pseudo_exec.  "echo foo | read bar" doesn't work on bash, either.
1571 	 */
1572 	if (pi->num_progs == 1) child = & (pi->progs[0]);
1573 #ifndef __U_BOOT__
1574 	if (pi->num_progs == 1 && child->group && child->subshell == 0) {
1575 		int squirrel[] = {-1, -1, -1};
1576 		int rcode;
1577 		debug_printf("non-subshell grouping\n");
1578 		setup_redirects(child, squirrel);
1579 		/* XXX could we merge code with following builtin case,
1580 		 * by creating a pseudo builtin that calls run_list_real? */
1581 		rcode = run_list_real(child->group);
1582 		restore_redirects(squirrel);
1583 #else
1584 		if (pi->num_progs == 1 && child->group) {
1585 		int rcode;
1586 		debug_printf("non-subshell grouping\n");
1587 		rcode = run_list_real(child->group);
1588 #endif
1589 		return rcode;
1590 	} else if (pi->num_progs == 1 && pi->progs[0].argv != NULL) {
1591 		for (i=0; is_assignment(child->argv[i]); i++) { /* nothing */ }
1592 		if (i!=0 && child->argv[i]==NULL) {
1593 			/* assignments, but no command: set the local environment */
1594 			for (i=0; child->argv[i]!=NULL; i++) {
1595 
1596 				/* Ok, this case is tricky.  We have to decide if this is a
1597 				 * local variable, or an already exported variable.  If it is
1598 				 * already exported, we have to export the new value.  If it is
1599 				 * not exported, we need only set this as a local variable.
1600 				 * This junk is all to decide whether or not to export this
1601 				 * variable. */
1602 				int export_me=0;
1603 				char *name, *value;
1604 				name = xstrdup(child->argv[i]);
1605 				debug_printf("Local environment set: %s\n", name);
1606 				value = strchr(name, '=');
1607 				if (value)
1608 					*value=0;
1609 #ifndef __U_BOOT__
1610 				if ( get_local_var(name)) {
1611 					export_me=1;
1612 				}
1613 #endif
1614 				free(name);
1615 				p = insert_var_value(child->argv[i]);
1616 				set_local_var(p, export_me);
1617 				if (p != child->argv[i]) free(p);
1618 			}
1619 			return EXIT_SUCCESS;   /* don't worry about errors in set_local_var() yet */
1620 		}
1621 		for (i = 0; is_assignment(child->argv[i]); i++) {
1622 			p = insert_var_value(child->argv[i]);
1623 #ifndef __U_BOOT__
1624 			putenv(strdup(p));
1625 #else
1626 			set_local_var(p, 0);
1627 #endif
1628 			if (p != child->argv[i]) {
1629 				child->sp--;
1630 				free(p);
1631 			}
1632 		}
1633 		if (child->sp) {
1634 			char * str = NULL;
1635 
1636 			str = make_string(child->argv + i,
1637 					  child->argv_nonnull + i);
1638 			parse_string_outer(str, FLAG_EXIT_FROM_LOOP | FLAG_REPARSING);
1639 			free(str);
1640 			return last_return_code;
1641 		}
1642 #ifndef __U_BOOT__
1643 		for (x = bltins; x->cmd; x++) {
1644 			if (strcmp(child->argv[i], x->cmd) == 0 ) {
1645 				int squirrel[] = {-1, -1, -1};
1646 				int rcode;
1647 				if (x->function == builtin_exec && child->argv[i+1]==NULL) {
1648 					debug_printf("magic exec\n");
1649 					setup_redirects(child,NULL);
1650 					return EXIT_SUCCESS;
1651 				}
1652 				debug_printf("builtin inline %s\n", child->argv[0]);
1653 				/* XXX setup_redirects acts on file descriptors, not FILEs.
1654 				 * This is perfect for work that comes after exec().
1655 				 * Is it really safe for inline use?  Experimentally,
1656 				 * things seem to work with glibc. */
1657 				setup_redirects(child, squirrel);
1658 
1659 				child->argv += i;  /* XXX horrible hack */
1660 				rcode = x->function(child);
1661 				/* XXX restore hack so free() can work right */
1662 				child->argv -= i;
1663 				restore_redirects(squirrel);
1664 			}
1665 			return rcode;
1666 		}
1667 #else
1668 		/* check ";", because ,example , argv consist from
1669 		 * "help;flinfo" must not execute
1670 		 */
1671 		if (strchr(child->argv[i], ';')) {
1672 			printf("Unknown command '%s' - try 'help' or use "
1673 					"'run' command\n", child->argv[i]);
1674 			return -1;
1675 		}
1676 		/* Process the command */
1677 		return cmd_process(flag, child->argc, child->argv,
1678 				   &flag_repeat, NULL);
1679 #endif
1680 	}
1681 #ifndef __U_BOOT__
1682 
1683 	for (i = 0; i < pi->num_progs; i++) {
1684 		child = & (pi->progs[i]);
1685 
1686 		/* pipes are inserted between pairs of commands */
1687 		if ((i + 1) < pi->num_progs) {
1688 			if (pipe(pipefds)<0) perror_msg_and_die("pipe");
1689 			nextout = pipefds[1];
1690 		} else {
1691 			nextout=1;
1692 			pipefds[0] = -1;
1693 		}
1694 
1695 		/* XXX test for failed fork()? */
1696 		if (!(child->pid = fork())) {
1697 			/* Set the handling for job control signals back to the default.  */
1698 			signal(SIGINT, SIG_DFL);
1699 			signal(SIGQUIT, SIG_DFL);
1700 			signal(SIGTERM, SIG_DFL);
1701 			signal(SIGTSTP, SIG_DFL);
1702 			signal(SIGTTIN, SIG_DFL);
1703 			signal(SIGTTOU, SIG_DFL);
1704 			signal(SIGCHLD, SIG_DFL);
1705 
1706 			close_all();
1707 
1708 			if (nextin != 0) {
1709 				dup2(nextin, 0);
1710 				close(nextin);
1711 			}
1712 			if (nextout != 1) {
1713 				dup2(nextout, 1);
1714 				close(nextout);
1715 			}
1716 			if (pipefds[0]!=-1) {
1717 				close(pipefds[0]);  /* opposite end of our output pipe */
1718 			}
1719 
1720 			/* Like bash, explicit redirects override pipes,
1721 			 * and the pipe fd is available for dup'ing. */
1722 			setup_redirects(child,NULL);
1723 
1724 			if (interactive && pi->followup!=PIPE_BG) {
1725 				/* If we (the child) win the race, put ourselves in the process
1726 				 * group whose leader is the first process in this pipe. */
1727 				if (pi->pgrp < 0) {
1728 					pi->pgrp = getpid();
1729 				}
1730 				if (setpgid(0, pi->pgrp) == 0) {
1731 					tcsetpgrp(2, pi->pgrp);
1732 				}
1733 			}
1734 
1735 			pseudo_exec(child);
1736 		}
1737 
1738 
1739 		/* put our child in the process group whose leader is the
1740 		   first process in this pipe */
1741 		if (pi->pgrp < 0) {
1742 			pi->pgrp = child->pid;
1743 		}
1744 		/* Don't check for errors.  The child may be dead already,
1745 		 * in which case setpgid returns error code EACCES. */
1746 		setpgid(child->pid, pi->pgrp);
1747 
1748 		if (nextin != 0)
1749 			close(nextin);
1750 		if (nextout != 1)
1751 			close(nextout);
1752 
1753 		/* If there isn't another process, nextin is garbage
1754 		   but it doesn't matter */
1755 		nextin = pipefds[0];
1756 	}
1757 #endif
1758 	return -1;
1759 }
1760 
1761 static int run_list_real(struct pipe *pi)
1762 {
1763 	char *save_name = NULL;
1764 	char **list = NULL;
1765 	char **save_list = NULL;
1766 	struct pipe *rpipe;
1767 	int flag_rep = 0;
1768 #ifndef __U_BOOT__
1769 	int save_num_progs;
1770 #endif
1771 	int rcode=0, flag_skip=1;
1772 	int flag_restore = 0;
1773 	int if_code=0, next_if_code=0;  /* need double-buffer to handle elif */
1774 	reserved_style rmode, skip_more_in_this_rmode=RES_XXXX;
1775 	/* check syntax for "for" */
1776 	for (rpipe = pi; rpipe; rpipe = rpipe->next) {
1777 		if ((rpipe->r_mode == RES_IN ||
1778 		    rpipe->r_mode == RES_FOR) &&
1779 		    (rpipe->next == NULL)) {
1780 				syntax();
1781 #ifdef __U_BOOT__
1782 				flag_repeat = 0;
1783 #endif
1784 				return 1;
1785 		}
1786 		if ((rpipe->r_mode == RES_IN &&
1787 			(rpipe->next->r_mode == RES_IN &&
1788 			rpipe->next->progs->argv != NULL))||
1789 			(rpipe->r_mode == RES_FOR &&
1790 			rpipe->next->r_mode != RES_IN)) {
1791 				syntax();
1792 #ifdef __U_BOOT__
1793 				flag_repeat = 0;
1794 #endif
1795 				return 1;
1796 		}
1797 	}
1798 	for (; pi; pi = (flag_restore != 0) ? rpipe : pi->next) {
1799 		if (pi->r_mode == RES_WHILE || pi->r_mode == RES_UNTIL ||
1800 			pi->r_mode == RES_FOR) {
1801 #ifdef __U_BOOT__
1802 				/* check Ctrl-C */
1803 				ctrlc();
1804 				if ((had_ctrlc())) {
1805 					return 1;
1806 				}
1807 #endif
1808 				flag_restore = 0;
1809 				if (!rpipe) {
1810 					flag_rep = 0;
1811 					rpipe = pi;
1812 				}
1813 		}
1814 		rmode = pi->r_mode;
1815 		debug_printf("rmode=%d  if_code=%d  next_if_code=%d skip_more=%d\n", rmode, if_code, next_if_code, skip_more_in_this_rmode);
1816 		if (rmode == skip_more_in_this_rmode && flag_skip) {
1817 			if (pi->followup == PIPE_SEQ) flag_skip=0;
1818 			continue;
1819 		}
1820 		flag_skip = 1;
1821 		skip_more_in_this_rmode = RES_XXXX;
1822 		if (rmode == RES_THEN || rmode == RES_ELSE) if_code = next_if_code;
1823 		if (rmode == RES_THEN &&  if_code) continue;
1824 		if (rmode == RES_ELSE && !if_code) continue;
1825 		if (rmode == RES_ELIF && !if_code) break;
1826 		if (rmode == RES_FOR && pi->num_progs) {
1827 			if (!list) {
1828 				/* if no variable values after "in" we skip "for" */
1829 				if (!pi->next->progs->argv) continue;
1830 				/* create list of variable values */
1831 				list = make_list_in(pi->next->progs->argv,
1832 					pi->progs->argv[0]);
1833 				save_list = list;
1834 				save_name = pi->progs->argv[0];
1835 				pi->progs->argv[0] = NULL;
1836 				flag_rep = 1;
1837 			}
1838 			if (!(*list)) {
1839 				free(pi->progs->argv[0]);
1840 				free(save_list);
1841 				list = NULL;
1842 				flag_rep = 0;
1843 				pi->progs->argv[0] = save_name;
1844 #ifndef __U_BOOT__
1845 				pi->progs->glob_result.gl_pathv[0] =
1846 					pi->progs->argv[0];
1847 #endif
1848 				continue;
1849 			} else {
1850 				/* insert new value from list for variable */
1851 				if (pi->progs->argv[0])
1852 					free(pi->progs->argv[0]);
1853 				pi->progs->argv[0] = *list++;
1854 #ifndef __U_BOOT__
1855 				pi->progs->glob_result.gl_pathv[0] =
1856 					pi->progs->argv[0];
1857 #endif
1858 			}
1859 		}
1860 		if (rmode == RES_IN) continue;
1861 		if (rmode == RES_DO) {
1862 			if (!flag_rep) continue;
1863 		}
1864 		if (rmode == RES_DONE) {
1865 			if (flag_rep) {
1866 				flag_restore = 1;
1867 			} else {
1868 				rpipe = NULL;
1869 			}
1870 		}
1871 		if (pi->num_progs == 0) continue;
1872 #ifndef __U_BOOT__
1873 		save_num_progs = pi->num_progs; /* save number of programs */
1874 #endif
1875 		rcode = run_pipe_real(pi);
1876 		debug_printf("run_pipe_real returned %d\n",rcode);
1877 #ifndef __U_BOOT__
1878 		if (rcode!=-1) {
1879 			/* We only ran a builtin: rcode was set by the return value
1880 			 * of run_pipe_real(), and we don't need to wait for anything. */
1881 		} else if (pi->followup==PIPE_BG) {
1882 			/* XXX check bash's behavior with nontrivial pipes */
1883 			/* XXX compute jobid */
1884 			/* XXX what does bash do with attempts to background builtins? */
1885 			insert_bg_job(pi);
1886 			rcode = EXIT_SUCCESS;
1887 		} else {
1888 			if (interactive) {
1889 				/* move the new process group into the foreground */
1890 				if (tcsetpgrp(shell_terminal, pi->pgrp) && errno != ENOTTY)
1891 					perror_msg("tcsetpgrp-3");
1892 				rcode = checkjobs(pi);
1893 				/* move the shell to the foreground */
1894 				if (tcsetpgrp(shell_terminal, getpgid(0)) && errno != ENOTTY)
1895 					perror_msg("tcsetpgrp-4");
1896 			} else {
1897 				rcode = checkjobs(pi);
1898 			}
1899 			debug_printf("checkjobs returned %d\n",rcode);
1900 		}
1901 		last_return_code=rcode;
1902 #else
1903 		if (rcode < -1) {
1904 			last_return_code = -rcode - 2;
1905 			return -2;	/* exit */
1906 		}
1907 		last_return_code=(rcode == 0) ? 0 : 1;
1908 #endif
1909 #ifndef __U_BOOT__
1910 		pi->num_progs = save_num_progs; /* restore number of programs */
1911 #endif
1912 		if ( rmode == RES_IF || rmode == RES_ELIF )
1913 			next_if_code=rcode;  /* can be overwritten a number of times */
1914 		if (rmode == RES_WHILE)
1915 			flag_rep = !last_return_code;
1916 		if (rmode == RES_UNTIL)
1917 			flag_rep = last_return_code;
1918 		if ( (rcode==EXIT_SUCCESS && pi->followup==PIPE_OR) ||
1919 		     (rcode!=EXIT_SUCCESS && pi->followup==PIPE_AND) )
1920 			skip_more_in_this_rmode=rmode;
1921 #ifndef __U_BOOT__
1922 		checkjobs(NULL);
1923 #endif
1924 	}
1925 	return rcode;
1926 }
1927 
1928 /* broken, of course, but OK for testing */
1929 static char *indenter(int i)
1930 {
1931 	static char blanks[]="                                    ";
1932 	return &blanks[sizeof(blanks)-i-1];
1933 }
1934 
1935 /* return code is the exit status of the pipe */
1936 static int free_pipe(struct pipe *pi, int indent)
1937 {
1938 	char **p;
1939 	struct child_prog *child;
1940 #ifndef __U_BOOT__
1941 	struct redir_struct *r, *rnext;
1942 #endif
1943 	int a, i, ret_code=0;
1944 	char *ind = indenter(indent);
1945 
1946 #ifndef __U_BOOT__
1947 	if (pi->stopped_progs > 0)
1948 		return ret_code;
1949 	final_printf("%s run pipe: (pid %d)\n",ind,getpid());
1950 #endif
1951 	for (i=0; i<pi->num_progs; i++) {
1952 		child = &pi->progs[i];
1953 		final_printf("%s  command %d:\n",ind,i);
1954 		if (child->argv) {
1955 			for (a=0,p=child->argv; *p; a++,p++) {
1956 				final_printf("%s   argv[%d] = %s\n",ind,a,*p);
1957 			}
1958 #ifndef __U_BOOT__
1959 			globfree(&child->glob_result);
1960 #else
1961 			for (a = 0; a < child->argc; a++) {
1962 				free(child->argv[a]);
1963 			}
1964 			free(child->argv);
1965 			free(child->argv_nonnull);
1966 			child->argc = 0;
1967 #endif
1968 			child->argv=NULL;
1969 		} else if (child->group) {
1970 #ifndef __U_BOOT__
1971 			final_printf("%s   begin group (subshell:%d)\n",ind, child->subshell);
1972 #endif
1973 			ret_code = free_pipe_list(child->group,indent+3);
1974 			final_printf("%s   end group\n",ind);
1975 		} else {
1976 			final_printf("%s   (nil)\n",ind);
1977 		}
1978 #ifndef __U_BOOT__
1979 		for (r=child->redirects; r; r=rnext) {
1980 			final_printf("%s   redirect %d%s", ind, r->fd, redir_table[r->type].descrip);
1981 			if (r->dup == -1) {
1982 				/* guard against the case >$FOO, where foo is unset or blank */
1983 				if (r->word.gl_pathv) {
1984 					final_printf(" %s\n", *r->word.gl_pathv);
1985 					globfree(&r->word);
1986 				}
1987 			} else {
1988 				final_printf("&%d\n", r->dup);
1989 			}
1990 			rnext=r->next;
1991 			free(r);
1992 		}
1993 		child->redirects=NULL;
1994 #endif
1995 	}
1996 	free(pi->progs);   /* children are an array, they get freed all at once */
1997 	pi->progs=NULL;
1998 	return ret_code;
1999 }
2000 
2001 static int free_pipe_list(struct pipe *head, int indent)
2002 {
2003 	int rcode=0;   /* if list has no members */
2004 	struct pipe *pi, *next;
2005 	char *ind = indenter(indent);
2006 	for (pi=head; pi; pi=next) {
2007 		final_printf("%s pipe reserved mode %d\n", ind, pi->r_mode);
2008 		rcode = free_pipe(pi, indent);
2009 		final_printf("%s pipe followup code %d\n", ind, pi->followup);
2010 		next=pi->next;
2011 		pi->next=NULL;
2012 		free(pi);
2013 	}
2014 	return rcode;
2015 }
2016 
2017 /* Select which version we will use */
2018 static int run_list(struct pipe *pi)
2019 {
2020 	int rcode=0;
2021 #ifndef __U_BOOT__
2022 	if (fake_mode==0) {
2023 #endif
2024 		rcode = run_list_real(pi);
2025 #ifndef __U_BOOT__
2026 	}
2027 #endif
2028 	/* free_pipe_list has the side effect of clearing memory
2029 	 * In the long run that function can be merged with run_list_real,
2030 	 * but doing that now would hobble the debugging effort. */
2031 	free_pipe_list(pi,0);
2032 	return rcode;
2033 }
2034 
2035 /* The API for glob is arguably broken.  This routine pushes a non-matching
2036  * string into the output structure, removing non-backslashed backslashes.
2037  * If someone can prove me wrong, by performing this function within the
2038  * original glob(3) api, feel free to rewrite this routine into oblivion.
2039  * Return code (0 vs. GLOB_NOSPACE) matches glob(3).
2040  * XXX broken if the last character is '\\', check that before calling.
2041  */
2042 #ifndef __U_BOOT__
2043 static int globhack(const char *src, int flags, glob_t *pglob)
2044 {
2045 	int cnt=0, pathc;
2046 	const char *s;
2047 	char *dest;
2048 	for (cnt=1, s=src; s && *s; s++) {
2049 		if (*s == '\\') s++;
2050 		cnt++;
2051 	}
2052 	dest = malloc(cnt);
2053 	if (!dest) return GLOB_NOSPACE;
2054 	if (!(flags & GLOB_APPEND)) {
2055 		pglob->gl_pathv=NULL;
2056 		pglob->gl_pathc=0;
2057 		pglob->gl_offs=0;
2058 		pglob->gl_offs=0;
2059 	}
2060 	pathc = ++pglob->gl_pathc;
2061 	pglob->gl_pathv = realloc(pglob->gl_pathv, (pathc+1)*sizeof(*pglob->gl_pathv));
2062 	if (pglob->gl_pathv == NULL) return GLOB_NOSPACE;
2063 	pglob->gl_pathv[pathc-1]=dest;
2064 	pglob->gl_pathv[pathc]=NULL;
2065 	for (s=src; s && *s; s++, dest++) {
2066 		if (*s == '\\') s++;
2067 		*dest = *s;
2068 	}
2069 	*dest='\0';
2070 	return 0;
2071 }
2072 
2073 /* XXX broken if the last character is '\\', check that before calling */
2074 static int glob_needed(const char *s)
2075 {
2076 	for (; *s; s++) {
2077 		if (*s == '\\') s++;
2078 		if (strchr("*[?",*s)) return 1;
2079 	}
2080 	return 0;
2081 }
2082 
2083 #if 0
2084 static void globprint(glob_t *pglob)
2085 {
2086 	int i;
2087 	debug_printf("glob_t at %p:\n", pglob);
2088 	debug_printf("  gl_pathc=%d  gl_pathv=%p  gl_offs=%d  gl_flags=%d\n",
2089 		pglob->gl_pathc, pglob->gl_pathv, pglob->gl_offs, pglob->gl_flags);
2090 	for (i=0; i<pglob->gl_pathc; i++)
2091 		debug_printf("pglob->gl_pathv[%d] = %p = %s\n", i,
2092 			pglob->gl_pathv[i], pglob->gl_pathv[i]);
2093 }
2094 #endif
2095 
2096 static int xglob(o_string *dest, int flags, glob_t *pglob)
2097 {
2098 	int gr;
2099 
2100 	/* short-circuit for null word */
2101 	/* we can code this better when the debug_printf's are gone */
2102 	if (dest->length == 0) {
2103 		if (dest->nonnull) {
2104 			/* bash man page calls this an "explicit" null */
2105 			gr = globhack(dest->data, flags, pglob);
2106 			debug_printf("globhack returned %d\n",gr);
2107 		} else {
2108 			return 0;
2109 		}
2110 	} else if (glob_needed(dest->data)) {
2111 		gr = glob(dest->data, flags, NULL, pglob);
2112 		debug_printf("glob returned %d\n",gr);
2113 		if (gr == GLOB_NOMATCH) {
2114 			/* quote removal, or more accurately, backslash removal */
2115 			gr = globhack(dest->data, flags, pglob);
2116 			debug_printf("globhack returned %d\n",gr);
2117 		}
2118 	} else {
2119 		gr = globhack(dest->data, flags, pglob);
2120 		debug_printf("globhack returned %d\n",gr);
2121 	}
2122 	if (gr == GLOB_NOSPACE)
2123 		error_msg_and_die("out of memory during glob");
2124 	if (gr != 0) { /* GLOB_ABORTED ? */
2125 		error_msg("glob(3) error %d",gr);
2126 	}
2127 	/* globprint(glob_target); */
2128 	return gr;
2129 }
2130 #endif
2131 
2132 #ifdef __U_BOOT__
2133 static char *get_dollar_var(char ch);
2134 #endif
2135 
2136 /* This is used to get/check local shell variables */
2137 char *get_local_var(const char *s)
2138 {
2139 	struct variables *cur;
2140 
2141 	if (!s)
2142 		return NULL;
2143 
2144 #ifdef __U_BOOT__
2145 	if (*s == '$')
2146 		return get_dollar_var(s[1]);
2147 #endif
2148 
2149 	for (cur = top_vars; cur; cur=cur->next)
2150 		if(strcmp(cur->name, s)==0)
2151 			return cur->value;
2152 	return NULL;
2153 }
2154 
2155 /* This is used to set local shell variables
2156    flg_export==0 if only local (not exporting) variable
2157    flg_export==1 if "new" exporting environ
2158    flg_export>1  if current startup environ (not call putenv()) */
2159 int set_local_var(const char *s, int flg_export)
2160 {
2161 	char *name, *value;
2162 	int result=0;
2163 	struct variables *cur;
2164 
2165 #ifdef __U_BOOT__
2166 	/* might be possible! */
2167 	if (!isalpha(*s))
2168 		return -1;
2169 #endif
2170 
2171 	name=strdup(s);
2172 
2173 #ifdef __U_BOOT__
2174 	if (env_get(name) != NULL) {
2175 		printf ("ERROR: "
2176 				"There is a global environment variable with the same name.\n");
2177 		free(name);
2178 		return -1;
2179 	}
2180 #endif
2181 	/* Assume when we enter this function that we are already in
2182 	 * NAME=VALUE format.  So the first order of business is to
2183 	 * split 's' on the '=' into 'name' and 'value' */
2184 	value = strchr(name, '=');
2185 	if (value == NULL || *(value + 1) == 0) {
2186 		free(name);
2187 		return -1;
2188 	}
2189 	*value++ = 0;
2190 
2191 	for(cur = top_vars; cur; cur = cur->next) {
2192 		if(strcmp(cur->name, name)==0)
2193 			break;
2194 	}
2195 
2196 	if(cur) {
2197 		if(strcmp(cur->value, value)==0) {
2198 			if(flg_export>0 && cur->flg_export==0)
2199 				cur->flg_export=flg_export;
2200 			else
2201 				result++;
2202 		} else {
2203 			if(cur->flg_read_only) {
2204 				error_msg("%s: readonly variable", name);
2205 				result = -1;
2206 			} else {
2207 				if(flg_export>0 || cur->flg_export>1)
2208 					cur->flg_export=1;
2209 				free(cur->value);
2210 
2211 				cur->value = strdup(value);
2212 			}
2213 		}
2214 	} else {
2215 		cur = malloc(sizeof(struct variables));
2216 		if(!cur) {
2217 			result = -1;
2218 		} else {
2219 			cur->name = strdup(name);
2220 			if (cur->name == NULL) {
2221 				free(cur);
2222 				result = -1;
2223 			} else {
2224 				struct variables *bottom = top_vars;
2225 				cur->value = strdup(value);
2226 				cur->next = NULL;
2227 				cur->flg_export = flg_export;
2228 				cur->flg_read_only = 0;
2229 				while(bottom->next) bottom=bottom->next;
2230 				bottom->next = cur;
2231 			}
2232 		}
2233 	}
2234 
2235 #ifndef __U_BOOT__
2236 	if(result==0 && cur->flg_export==1) {
2237 		*(value-1) = '=';
2238 		result = putenv(name);
2239 	} else {
2240 #endif
2241 		free(name);
2242 #ifndef __U_BOOT__
2243 		if(result>0)            /* equivalent to previous set */
2244 			result = 0;
2245 	}
2246 #endif
2247 	return result;
2248 }
2249 
2250 void unset_local_var(const char *name)
2251 {
2252 	struct variables *cur;
2253 
2254 	if (name) {
2255 		for (cur = top_vars; cur; cur=cur->next) {
2256 			if(strcmp(cur->name, name)==0)
2257 				break;
2258 		}
2259 		if (cur != NULL) {
2260 			struct variables *next = top_vars;
2261 			if(cur->flg_read_only) {
2262 				error_msg("%s: readonly variable", name);
2263 				return;
2264 			} else {
2265 #ifndef __U_BOOT__
2266 				if(cur->flg_export)
2267 					unenv_set(cur->name);
2268 #endif
2269 				free(cur->name);
2270 				free(cur->value);
2271 				while (next->next != cur)
2272 					next = next->next;
2273 				next->next = cur->next;
2274 			}
2275 			free(cur);
2276 		}
2277 	}
2278 }
2279 
2280 static int is_assignment(const char *s)
2281 {
2282 	if (s == NULL)
2283 		return 0;
2284 
2285 	if (!isalpha(*s)) return 0;
2286 	++s;
2287 	while(isalnum(*s) || *s=='_') ++s;
2288 	return *s=='=';
2289 }
2290 
2291 #ifndef __U_BOOT__
2292 /* the src parameter allows us to peek forward to a possible &n syntax
2293  * for file descriptor duplication, e.g., "2>&1".
2294  * Return code is 0 normally, 1 if a syntax error is detected in src.
2295  * Resource errors (in xmalloc) cause the process to exit */
2296 static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
2297 	struct in_str *input)
2298 {
2299 	struct child_prog *child=ctx->child;
2300 	struct redir_struct *redir = child->redirects;
2301 	struct redir_struct *last_redir=NULL;
2302 
2303 	/* Create a new redir_struct and drop it onto the end of the linked list */
2304 	while(redir) {
2305 		last_redir=redir;
2306 		redir=redir->next;
2307 	}
2308 	redir = xmalloc(sizeof(struct redir_struct));
2309 	redir->next=NULL;
2310 	redir->word.gl_pathv=NULL;
2311 	if (last_redir) {
2312 		last_redir->next=redir;
2313 	} else {
2314 		child->redirects=redir;
2315 	}
2316 
2317 	redir->type=style;
2318 	redir->fd= (fd==-1) ? redir_table[style].default_fd : fd ;
2319 
2320 	debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
2321 
2322 	/* Check for a '2>&1' type redirect */
2323 	redir->dup = redirect_dup_num(input);
2324 	if (redir->dup == -2) return 1;  /* syntax error */
2325 	if (redir->dup != -1) {
2326 		/* Erik had a check here that the file descriptor in question
2327 		 * is legit; I postpone that to "run time"
2328 		 * A "-" representation of "close me" shows up as a -3 here */
2329 		debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
2330 	} else {
2331 		/* We do _not_ try to open the file that src points to,
2332 		 * since we need to return and let src be expanded first.
2333 		 * Set ctx->pending_redirect, so we know what to do at the
2334 		 * end of the next parsed word.
2335 		 */
2336 		ctx->pending_redirect = redir;
2337 	}
2338 	return 0;
2339 }
2340 #endif
2341 
2342 static struct pipe *new_pipe(void)
2343 {
2344 	struct pipe *pi;
2345 	pi = xmalloc(sizeof(struct pipe));
2346 	pi->num_progs = 0;
2347 	pi->progs = NULL;
2348 	pi->next = NULL;
2349 	pi->followup = 0;  /* invalid */
2350 	pi->r_mode = RES_NONE;
2351 	return pi;
2352 }
2353 
2354 static void initialize_context(struct p_context *ctx)
2355 {
2356 	ctx->pipe=NULL;
2357 #ifndef __U_BOOT__
2358 	ctx->pending_redirect=NULL;
2359 #endif
2360 	ctx->child=NULL;
2361 	ctx->list_head=new_pipe();
2362 	ctx->pipe=ctx->list_head;
2363 	ctx->w=RES_NONE;
2364 	ctx->stack=NULL;
2365 #ifdef __U_BOOT__
2366 	ctx->old_flag=0;
2367 #endif
2368 	done_command(ctx);   /* creates the memory for working child */
2369 }
2370 
2371 /* normal return is 0
2372  * if a reserved word is found, and processed, return 1
2373  * should handle if, then, elif, else, fi, for, while, until, do, done.
2374  * case, function, and select are obnoxious, save those for later.
2375  */
2376 struct reserved_combo {
2377 	char *literal;
2378 	int code;
2379 	long flag;
2380 };
2381 /* Mostly a list of accepted follow-up reserved words.
2382  * FLAG_END means we are done with the sequence, and are ready
2383  * to turn the compound list into a command.
2384  * FLAG_START means the word must start a new compound list.
2385  */
2386 static struct reserved_combo reserved_list[] = {
2387 	{ "if",    RES_IF,    FLAG_THEN | FLAG_START },
2388 	{ "then",  RES_THEN,  FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2389 	{ "elif",  RES_ELIF,  FLAG_THEN },
2390 	{ "else",  RES_ELSE,  FLAG_FI   },
2391 	{ "fi",    RES_FI,    FLAG_END  },
2392 	{ "for",   RES_FOR,   FLAG_IN   | FLAG_START },
2393 	{ "while", RES_WHILE, FLAG_DO   | FLAG_START },
2394 	{ "until", RES_UNTIL, FLAG_DO   | FLAG_START },
2395 	{ "in",    RES_IN,    FLAG_DO   },
2396 	{ "do",    RES_DO,    FLAG_DONE },
2397 	{ "done",  RES_DONE,  FLAG_END  }
2398 };
2399 #define NRES (sizeof(reserved_list)/sizeof(struct reserved_combo))
2400 
2401 static int reserved_word(o_string *dest, struct p_context *ctx)
2402 {
2403 	struct reserved_combo *r;
2404 	for (r=reserved_list;
2405 		r<reserved_list+NRES; r++) {
2406 		if (strcmp(dest->data, r->literal) == 0) {
2407 			debug_printf("found reserved word %s, code %d\n",r->literal,r->code);
2408 			if (r->flag & FLAG_START) {
2409 				struct p_context *new = xmalloc(sizeof(struct p_context));
2410 				debug_printf("push stack\n");
2411 				if (ctx->w == RES_IN || ctx->w == RES_FOR) {
2412 					syntax();
2413 					free(new);
2414 					ctx->w = RES_SNTX;
2415 					b_reset(dest);
2416 					return 1;
2417 				}
2418 				*new = *ctx;   /* physical copy */
2419 				initialize_context(ctx);
2420 				ctx->stack=new;
2421 			} else if ( ctx->w == RES_NONE || ! (ctx->old_flag & (1<<r->code))) {
2422 				syntax();
2423 				ctx->w = RES_SNTX;
2424 				b_reset(dest);
2425 				return 1;
2426 			}
2427 			ctx->w=r->code;
2428 			ctx->old_flag = r->flag;
2429 			if (ctx->old_flag & FLAG_END) {
2430 				struct p_context *old;
2431 				debug_printf("pop stack\n");
2432 				done_pipe(ctx,PIPE_SEQ);
2433 				old = ctx->stack;
2434 				old->child->group = ctx->list_head;
2435 #ifndef __U_BOOT__
2436 				old->child->subshell = 0;
2437 #endif
2438 				*ctx = *old;   /* physical copy */
2439 				free(old);
2440 			}
2441 			b_reset (dest);
2442 			return 1;
2443 		}
2444 	}
2445 	return 0;
2446 }
2447 
2448 /* normal return is 0.
2449  * Syntax or xglob errors return 1. */
2450 static int done_word(o_string *dest, struct p_context *ctx)
2451 {
2452 	struct child_prog *child=ctx->child;
2453 #ifndef __U_BOOT__
2454 	glob_t *glob_target;
2455 	int gr, flags = 0;
2456 #else
2457 	char *str, *s;
2458 	int argc, cnt;
2459 #endif
2460 
2461 	debug_printf("done_word: %s %p\n", dest->data, child);
2462 	if (dest->length == 0 && !dest->nonnull) {
2463 		debug_printf("  true null, ignored\n");
2464 		return 0;
2465 	}
2466 #ifndef __U_BOOT__
2467 	if (ctx->pending_redirect) {
2468 		glob_target = &ctx->pending_redirect->word;
2469 	} else {
2470 #endif
2471 		if (child->group) {
2472 			syntax();
2473 			return 1;  /* syntax error, groups and arglists don't mix */
2474 		}
2475 		if (!child->argv && (ctx->type & FLAG_PARSE_SEMICOLON)) {
2476 			debug_printf("checking %s for reserved-ness\n",dest->data);
2477 			if (reserved_word(dest,ctx)) return ctx->w==RES_SNTX;
2478 		}
2479 #ifndef __U_BOOT__
2480 		glob_target = &child->glob_result;
2481 		if (child->argv) flags |= GLOB_APPEND;
2482 #else
2483 		for (cnt = 1, s = dest->data; s && *s; s++) {
2484 			if (*s == '\\') s++;
2485 			cnt++;
2486 		}
2487 		str = malloc(cnt);
2488 		if (!str) return 1;
2489 		if ( child->argv == NULL) {
2490 			child->argc=0;
2491 		}
2492 		argc = ++child->argc;
2493 		child->argv = realloc(child->argv, (argc+1)*sizeof(*child->argv));
2494 		if (child->argv == NULL) {
2495 			free(str);
2496 			return 1;
2497 		}
2498 		child->argv_nonnull = realloc(child->argv_nonnull,
2499 					(argc+1)*sizeof(*child->argv_nonnull));
2500 		if (child->argv_nonnull == NULL) {
2501 			free(str);
2502 			return 1;
2503 		}
2504 		child->argv[argc-1]=str;
2505 		child->argv_nonnull[argc-1] = dest->nonnull;
2506 		child->argv[argc]=NULL;
2507 		child->argv_nonnull[argc] = 0;
2508 		for (s = dest->data; s && *s; s++,str++) {
2509 			if (*s == '\\') s++;
2510 			*str = *s;
2511 		}
2512 		*str = '\0';
2513 #endif
2514 #ifndef __U_BOOT__
2515 	}
2516 	gr = xglob(dest, flags, glob_target);
2517 	if (gr != 0) return 1;
2518 #endif
2519 
2520 	b_reset(dest);
2521 #ifndef __U_BOOT__
2522 	if (ctx->pending_redirect) {
2523 		ctx->pending_redirect=NULL;
2524 		if (glob_target->gl_pathc != 1) {
2525 			error_msg("ambiguous redirect");
2526 			return 1;
2527 		}
2528 	} else {
2529 		child->argv = glob_target->gl_pathv;
2530 	}
2531 #endif
2532 	if (ctx->w == RES_FOR) {
2533 		done_word(dest,ctx);
2534 		done_pipe(ctx,PIPE_SEQ);
2535 	}
2536 	return 0;
2537 }
2538 
2539 /* The only possible error here is out of memory, in which case
2540  * xmalloc exits. */
2541 static int done_command(struct p_context *ctx)
2542 {
2543 	/* The child is really already in the pipe structure, so
2544 	 * advance the pipe counter and make a new, null child.
2545 	 * Only real trickiness here is that the uncommitted
2546 	 * child structure, to which ctx->child points, is not
2547 	 * counted in pi->num_progs. */
2548 	struct pipe *pi=ctx->pipe;
2549 	struct child_prog *prog=ctx->child;
2550 
2551 	if (prog && prog->group == NULL
2552 		 && prog->argv == NULL
2553 #ifndef __U_BOOT__
2554 		 && prog->redirects == NULL) {
2555 #else
2556 										) {
2557 #endif
2558 		debug_printf("done_command: skipping null command\n");
2559 		return 0;
2560 	} else if (prog) {
2561 		pi->num_progs++;
2562 		debug_printf("done_command: num_progs incremented to %d\n",pi->num_progs);
2563 	} else {
2564 		debug_printf("done_command: initializing\n");
2565 	}
2566 	pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
2567 
2568 	prog = pi->progs + pi->num_progs;
2569 #ifndef __U_BOOT__
2570 	prog->redirects = NULL;
2571 #endif
2572 	prog->argv = NULL;
2573 	prog->argv_nonnull = NULL;
2574 #ifndef __U_BOOT__
2575 	prog->is_stopped = 0;
2576 #endif
2577 	prog->group = NULL;
2578 #ifndef __U_BOOT__
2579 	prog->glob_result.gl_pathv = NULL;
2580 	prog->family = pi;
2581 #endif
2582 	prog->sp = 0;
2583 	ctx->child = prog;
2584 	prog->type = ctx->type;
2585 
2586 	/* but ctx->pipe and ctx->list_head remain unchanged */
2587 	return 0;
2588 }
2589 
2590 static int done_pipe(struct p_context *ctx, pipe_style type)
2591 {
2592 	struct pipe *new_p;
2593 	done_command(ctx);  /* implicit closure of previous command */
2594 	debug_printf("done_pipe, type %d\n", type);
2595 	ctx->pipe->followup = type;
2596 	ctx->pipe->r_mode = ctx->w;
2597 	new_p=new_pipe();
2598 	ctx->pipe->next = new_p;
2599 	ctx->pipe = new_p;
2600 	ctx->child = NULL;
2601 	done_command(ctx);  /* set up new pipe to accept commands */
2602 	return 0;
2603 }
2604 
2605 #ifndef __U_BOOT__
2606 /* peek ahead in the in_str to find out if we have a "&n" construct,
2607  * as in "2>&1", that represents duplicating a file descriptor.
2608  * returns either -2 (syntax error), -1 (no &), or the number found.
2609  */
2610 static int redirect_dup_num(struct in_str *input)
2611 {
2612 	int ch, d=0, ok=0;
2613 	ch = b_peek(input);
2614 	if (ch != '&') return -1;
2615 
2616 	b_getch(input);  /* get the & */
2617 	ch=b_peek(input);
2618 	if (ch == '-') {
2619 		b_getch(input);
2620 		return -3;  /* "-" represents "close me" */
2621 	}
2622 	while (isdigit(ch)) {
2623 		d = d*10+(ch-'0');
2624 		ok=1;
2625 		b_getch(input);
2626 		ch = b_peek(input);
2627 	}
2628 	if (ok) return d;
2629 
2630 	error_msg("ambiguous redirect");
2631 	return -2;
2632 }
2633 
2634 /* If a redirect is immediately preceded by a number, that number is
2635  * supposed to tell which file descriptor to redirect.  This routine
2636  * looks for such preceding numbers.  In an ideal world this routine
2637  * needs to handle all the following classes of redirects...
2638  *     echo 2>foo     # redirects fd  2 to file "foo", nothing passed to echo
2639  *     echo 49>foo    # redirects fd 49 to file "foo", nothing passed to echo
2640  *     echo -2>foo    # redirects fd  1 to file "foo",    "-2" passed to echo
2641  *     echo 49x>foo   # redirects fd  1 to file "foo",   "49x" passed to echo
2642  * A -1 output from this program means no valid number was found, so the
2643  * caller should use the appropriate default for this redirection.
2644  */
2645 static int redirect_opt_num(o_string *o)
2646 {
2647 	int num;
2648 
2649 	if (o->length==0) return -1;
2650 	for(num=0; num<o->length; num++) {
2651 		if (!isdigit(*(o->data+num))) {
2652 			return -1;
2653 		}
2654 	}
2655 	/* reuse num (and save an int) */
2656 	num=atoi(o->data);
2657 	b_reset(o);
2658 	return num;
2659 }
2660 
2661 FILE *generate_stream_from_list(struct pipe *head)
2662 {
2663 	FILE *pf;
2664 #if 1
2665 	int pid, channel[2];
2666 	if (pipe(channel)<0) perror_msg_and_die("pipe");
2667 	pid=fork();
2668 	if (pid<0) {
2669 		perror_msg_and_die("fork");
2670 	} else if (pid==0) {
2671 		close(channel[0]);
2672 		if (channel[1] != 1) {
2673 			dup2(channel[1],1);
2674 			close(channel[1]);
2675 		}
2676 #if 0
2677 #define SURROGATE "surrogate response"
2678 		write(1,SURROGATE,sizeof(SURROGATE));
2679 		_exit(run_list(head));
2680 #else
2681 		_exit(run_list_real(head));   /* leaks memory */
2682 #endif
2683 	}
2684 	debug_printf("forked child %d\n",pid);
2685 	close(channel[1]);
2686 	pf = fdopen(channel[0],"r");
2687 	debug_printf("pipe on FILE *%p\n",pf);
2688 #else
2689 	free_pipe_list(head,0);
2690 	pf=popen("echo surrogate response","r");
2691 	debug_printf("started fake pipe on FILE *%p\n",pf);
2692 #endif
2693 	return pf;
2694 }
2695 
2696 /* this version hacked for testing purposes */
2697 /* return code is exit status of the process that is run. */
2698 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end)
2699 {
2700 	int retcode;
2701 	o_string result=NULL_O_STRING;
2702 	struct p_context inner;
2703 	FILE *p;
2704 	struct in_str pipe_str;
2705 	initialize_context(&inner);
2706 
2707 	/* recursion to generate command */
2708 	retcode = parse_stream(&result, &inner, input, subst_end);
2709 	if (retcode != 0) return retcode;  /* syntax error or EOF */
2710 	done_word(&result, &inner);
2711 	done_pipe(&inner, PIPE_SEQ);
2712 	b_free(&result);
2713 
2714 	p=generate_stream_from_list(inner.list_head);
2715 	if (p==NULL) return 1;
2716 	mark_open(fileno(p));
2717 	setup_file_in_str(&pipe_str, p);
2718 
2719 	/* now send results of command back into original context */
2720 	retcode = parse_stream(dest, ctx, &pipe_str, '\0');
2721 	/* XXX In case of a syntax error, should we try to kill the child?
2722 	 * That would be tough to do right, so just read until EOF. */
2723 	if (retcode == 1) {
2724 		while (b_getch(&pipe_str)!=EOF) { /* discard */ };
2725 	}
2726 
2727 	debug_printf("done reading from pipe, pclose()ing\n");
2728 	/* This is the step that wait()s for the child.  Should be pretty
2729 	 * safe, since we just read an EOF from its stdout.  We could try
2730 	 * to better, by using wait(), and keeping track of background jobs
2731 	 * at the same time.  That would be a lot of work, and contrary
2732 	 * to the KISS philosophy of this program. */
2733 	mark_closed(fileno(p));
2734 	retcode=pclose(p);
2735 	free_pipe_list(inner.list_head,0);
2736 	debug_printf("pclosed, retcode=%d\n",retcode);
2737 	/* XXX this process fails to trim a single trailing newline */
2738 	return retcode;
2739 }
2740 
2741 static int parse_group(o_string *dest, struct p_context *ctx,
2742 	struct in_str *input, int ch)
2743 {
2744 	int rcode, endch=0;
2745 	struct p_context sub;
2746 	struct child_prog *child = ctx->child;
2747 	if (child->argv) {
2748 		syntax();
2749 		return 1;  /* syntax error, groups and arglists don't mix */
2750 	}
2751 	initialize_context(&sub);
2752 	switch(ch) {
2753 		case '(': endch=')'; child->subshell=1; break;
2754 		case '{': endch='}'; break;
2755 		default: syntax();   /* really logic error */
2756 	}
2757 	rcode=parse_stream(dest,&sub,input,endch);
2758 	done_word(dest,&sub); /* finish off the final word in the subcontext */
2759 	done_pipe(&sub, PIPE_SEQ);  /* and the final command there, too */
2760 	child->group = sub.list_head;
2761 	return rcode;
2762 	/* child remains "open", available for possible redirects */
2763 }
2764 #endif
2765 
2766 /* basically useful version until someone wants to get fancier,
2767  * see the bash man page under "Parameter Expansion" */
2768 static char *lookup_param(char *src)
2769 {
2770 	char *p;
2771 	char *sep;
2772 	char *default_val = NULL;
2773 	int assign = 0;
2774 	int expand_empty = 0;
2775 
2776 	if (!src)
2777 		return NULL;
2778 
2779 	sep = strchr(src, ':');
2780 
2781 	if (sep) {
2782 		*sep = '\0';
2783 		if (*(sep + 1) == '-')
2784 			default_val = sep+2;
2785 		if (*(sep + 1) == '=') {
2786 			default_val = sep+2;
2787 			assign = 1;
2788 		}
2789 		if (*(sep + 1) == '+') {
2790 			default_val = sep+2;
2791 			expand_empty = 1;
2792 		}
2793 	}
2794 
2795 	p = env_get(src);
2796 	if (!p)
2797 		p = get_local_var(src);
2798 
2799 	if (!p || strlen(p) == 0) {
2800 		p = default_val;
2801 		if (assign) {
2802 			char *var = malloc(strlen(src)+strlen(default_val)+2);
2803 			if (var) {
2804 				sprintf(var, "%s=%s", src, default_val);
2805 				set_local_var(var, 0);
2806 			}
2807 			free(var);
2808 		}
2809 	} else if (expand_empty) {
2810 		p += strlen(p);
2811 	}
2812 
2813 	if (sep)
2814 		*sep = ':';
2815 
2816 	return p;
2817 }
2818 
2819 #ifdef __U_BOOT__
2820 static char *get_dollar_var(char ch)
2821 {
2822 	static char buf[40];
2823 
2824 	buf[0] = '\0';
2825 	switch (ch) {
2826 		case '?':
2827 			sprintf(buf, "%u", (unsigned int)last_return_code);
2828 			break;
2829 		default:
2830 			return NULL;
2831 	}
2832 	return buf;
2833 }
2834 #endif
2835 
2836 /* return code: 0 for OK, 1 for syntax error */
2837 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input)
2838 {
2839 #ifndef __U_BOOT__
2840 	int i, advance=0;
2841 #else
2842 	int advance=0;
2843 #endif
2844 #ifndef __U_BOOT__
2845 	char sep[]=" ";
2846 #endif
2847 	int ch = input->peek(input);  /* first character after the $ */
2848 	debug_printf("handle_dollar: ch=%c\n",ch);
2849 	if (isalpha(ch)) {
2850 		b_addchr(dest, SPECIAL_VAR_SYMBOL);
2851 		ctx->child->sp++;
2852 		while(ch=b_peek(input),isalnum(ch) || ch=='_') {
2853 			b_getch(input);
2854 			b_addchr(dest,ch);
2855 		}
2856 		b_addchr(dest, SPECIAL_VAR_SYMBOL);
2857 #ifndef __U_BOOT__
2858 	} else if (isdigit(ch)) {
2859 		i = ch-'0';  /* XXX is $0 special? */
2860 		if (i<global_argc) {
2861 			parse_string(dest, ctx, global_argv[i]); /* recursion */
2862 		}
2863 		advance = 1;
2864 #endif
2865 	} else switch (ch) {
2866 #ifndef __U_BOOT__
2867 		case '$':
2868 			b_adduint(dest,getpid());
2869 			advance = 1;
2870 			break;
2871 		case '!':
2872 			if (last_bg_pid > 0) b_adduint(dest, last_bg_pid);
2873 			advance = 1;
2874 			break;
2875 #endif
2876 		case '?':
2877 #ifndef __U_BOOT__
2878 			b_adduint(dest,last_return_code);
2879 #else
2880 			ctx->child->sp++;
2881 			b_addchr(dest, SPECIAL_VAR_SYMBOL);
2882 			b_addchr(dest, '$');
2883 			b_addchr(dest, '?');
2884 			b_addchr(dest, SPECIAL_VAR_SYMBOL);
2885 #endif
2886 			advance = 1;
2887 			break;
2888 #ifndef __U_BOOT__
2889 		case '#':
2890 			b_adduint(dest,global_argc ? global_argc-1 : 0);
2891 			advance = 1;
2892 			break;
2893 #endif
2894 		case '{':
2895 			b_addchr(dest, SPECIAL_VAR_SYMBOL);
2896 			ctx->child->sp++;
2897 			b_getch(input);
2898 			/* XXX maybe someone will try to escape the '}' */
2899 			while(ch=b_getch(input),ch!=EOF && ch!='}') {
2900 				b_addchr(dest,ch);
2901 			}
2902 			if (ch != '}') {
2903 				syntax();
2904 				return 1;
2905 			}
2906 			b_addchr(dest, SPECIAL_VAR_SYMBOL);
2907 			break;
2908 #ifndef __U_BOOT__
2909 		case '(':
2910 			b_getch(input);
2911 			process_command_subs(dest, ctx, input, ')');
2912 			break;
2913 		case '*':
2914 			sep[0]=ifs[0];
2915 			for (i=1; i<global_argc; i++) {
2916 				parse_string(dest, ctx, global_argv[i]);
2917 				if (i+1 < global_argc) parse_string(dest, ctx, sep);
2918 			}
2919 			break;
2920 		case '@':
2921 		case '-':
2922 		case '_':
2923 			/* still unhandled, but should be eventually */
2924 			error_msg("unhandled syntax: $%c",ch);
2925 			return 1;
2926 			break;
2927 #endif
2928 		default:
2929 			b_addqchr(dest,'$',dest->quote);
2930 	}
2931 	/* Eat the character if the flag was set.  If the compiler
2932 	 * is smart enough, we could substitute "b_getch(input);"
2933 	 * for all the "advance = 1;" above, and also end up with
2934 	 * a nice size-optimized program.  Hah!  That'll be the day.
2935 	 */
2936 	if (advance) b_getch(input);
2937 	return 0;
2938 }
2939 
2940 #ifndef __U_BOOT__
2941 int parse_string(o_string *dest, struct p_context *ctx, const char *src)
2942 {
2943 	struct in_str foo;
2944 	setup_string_in_str(&foo, src);
2945 	return parse_stream(dest, ctx, &foo, '\0');
2946 }
2947 #endif
2948 
2949 /* return code is 0 for normal exit, 1 for syntax error */
2950 static int parse_stream(o_string *dest, struct p_context *ctx,
2951 			struct in_str *input, int end_trigger)
2952 {
2953 	unsigned int ch, m;
2954 #ifndef __U_BOOT__
2955 	int redir_fd;
2956 	redir_type redir_style;
2957 #endif
2958 	int next;
2959 
2960 	/* Only double-quote state is handled in the state variable dest->quote.
2961 	 * A single-quote triggers a bypass of the main loop until its mate is
2962 	 * found.  When recursing, quote state is passed in via dest->quote. */
2963 
2964 	debug_printf("parse_stream, end_trigger=%d\n",end_trigger);
2965 	while ((ch=b_getch(input))!=EOF) {
2966 		m = map[ch];
2967 #ifdef __U_BOOT__
2968 		if (input->__promptme == 0) return 1;
2969 #endif
2970 		next = (ch == '\n') ? 0 : b_peek(input);
2971 
2972 		debug_printf("parse_stream: ch=%c (%d) m=%d quote=%d - %c\n",
2973 			ch >= ' ' ? ch : '.', ch, m,
2974 			dest->quote, ctx->stack == NULL ? '*' : '.');
2975 
2976 		if (m==0 || ((m==1 || m==2) && dest->quote)) {
2977 			b_addqchr(dest, ch, dest->quote);
2978 		} else {
2979 			if (m==2) {  /* unquoted IFS */
2980 				if (done_word(dest, ctx)) {
2981 					return 1;
2982 				}
2983 				/* If we aren't performing a substitution, treat a newline as a
2984 				 * command separator.  */
2985 				if (end_trigger != '\0' && ch=='\n')
2986 					done_pipe(ctx,PIPE_SEQ);
2987 			}
2988 			if (ch == end_trigger && !dest->quote && ctx->w==RES_NONE) {
2989 				debug_printf("leaving parse_stream (triggered)\n");
2990 				return 0;
2991 			}
2992 #if 0
2993 			if (ch=='\n') {
2994 				/* Yahoo!  Time to run with it! */
2995 				done_pipe(ctx,PIPE_SEQ);
2996 				run_list(ctx->list_head);
2997 				initialize_context(ctx);
2998 			}
2999 #endif
3000 			if (m!=2) switch (ch) {
3001 		case '#':
3002 			if (dest->length == 0 && !dest->quote) {
3003 				while(ch=b_peek(input),ch!=EOF && ch!='\n') { b_getch(input); }
3004 			} else {
3005 				b_addqchr(dest, ch, dest->quote);
3006 			}
3007 			break;
3008 		case '\\':
3009 			if (next == EOF) {
3010 				syntax();
3011 				return 1;
3012 			}
3013 			b_addqchr(dest, '\\', dest->quote);
3014 			b_addqchr(dest, b_getch(input), dest->quote);
3015 			break;
3016 		case '$':
3017 			if (handle_dollar(dest, ctx, input)!=0) return 1;
3018 			break;
3019 		case '\'':
3020 			dest->nonnull = 1;
3021 			while(ch=b_getch(input),ch!=EOF && ch!='\'') {
3022 #ifdef __U_BOOT__
3023 				if(input->__promptme == 0) return 1;
3024 #endif
3025 				b_addchr(dest,ch);
3026 			}
3027 			if (ch==EOF) {
3028 				syntax();
3029 				return 1;
3030 			}
3031 			break;
3032 		case '"':
3033 			dest->nonnull = 1;
3034 			dest->quote = !dest->quote;
3035 			break;
3036 #ifndef __U_BOOT__
3037 		case '`':
3038 			process_command_subs(dest, ctx, input, '`');
3039 			break;
3040 		case '>':
3041 			redir_fd = redirect_opt_num(dest);
3042 			done_word(dest, ctx);
3043 			redir_style=REDIRECT_OVERWRITE;
3044 			if (next == '>') {
3045 				redir_style=REDIRECT_APPEND;
3046 				b_getch(input);
3047 			} else if (next == '(') {
3048 				syntax();   /* until we support >(list) Process Substitution */
3049 				return 1;
3050 			}
3051 			setup_redirect(ctx, redir_fd, redir_style, input);
3052 			break;
3053 		case '<':
3054 			redir_fd = redirect_opt_num(dest);
3055 			done_word(dest, ctx);
3056 			redir_style=REDIRECT_INPUT;
3057 			if (next == '<') {
3058 				redir_style=REDIRECT_HEREIS;
3059 				b_getch(input);
3060 			} else if (next == '>') {
3061 				redir_style=REDIRECT_IO;
3062 				b_getch(input);
3063 			} else if (next == '(') {
3064 				syntax();   /* until we support <(list) Process Substitution */
3065 				return 1;
3066 			}
3067 			setup_redirect(ctx, redir_fd, redir_style, input);
3068 			break;
3069 #endif
3070 		case ';':
3071 			done_word(dest, ctx);
3072 			done_pipe(ctx,PIPE_SEQ);
3073 			break;
3074 		case '&':
3075 			done_word(dest, ctx);
3076 			if (next=='&') {
3077 				b_getch(input);
3078 				done_pipe(ctx,PIPE_AND);
3079 			} else {
3080 #ifndef __U_BOOT__
3081 				done_pipe(ctx,PIPE_BG);
3082 #else
3083 				syntax_err();
3084 				return 1;
3085 #endif
3086 			}
3087 			break;
3088 		case '|':
3089 			done_word(dest, ctx);
3090 			if (next=='|') {
3091 				b_getch(input);
3092 				done_pipe(ctx,PIPE_OR);
3093 			} else {
3094 				/* we could pick up a file descriptor choice here
3095 				 * with redirect_opt_num(), but bash doesn't do it.
3096 				 * "echo foo 2| cat" yields "foo 2". */
3097 #ifndef __U_BOOT__
3098 				done_command(ctx);
3099 #else
3100 				syntax_err();
3101 				return 1;
3102 #endif
3103 			}
3104 			break;
3105 #ifndef __U_BOOT__
3106 		case '(':
3107 		case '{':
3108 			if (parse_group(dest, ctx, input, ch)!=0) return 1;
3109 			break;
3110 		case ')':
3111 		case '}':
3112 			syntax();   /* Proper use of this character caught by end_trigger */
3113 			return 1;
3114 			break;
3115 #endif
3116 		case SUBSTED_VAR_SYMBOL:
3117 			dest->nonnull = 1;
3118 			while (ch = b_getch(input), ch != EOF &&
3119 			    ch != SUBSTED_VAR_SYMBOL) {
3120 				debug_printf("subst, pass=%d\n", ch);
3121 				if (input->__promptme == 0)
3122 					return 1;
3123 				b_addchr(dest, ch);
3124 			}
3125 			debug_printf("subst, term=%d\n", ch);
3126 			if (ch == EOF) {
3127 				syntax();
3128 				return 1;
3129 			}
3130 			break;
3131 		default:
3132 			syntax();   /* this is really an internal logic error */
3133 			return 1;
3134 			}
3135 		}
3136 	}
3137 	/* complain if quote?  No, maybe we just finished a command substitution
3138 	 * that was quoted.  Example:
3139 	 * $ echo "`cat foo` plus more"
3140 	 * and we just got the EOF generated by the subshell that ran "cat foo"
3141 	 * The only real complaint is if we got an EOF when end_trigger != '\0',
3142 	 * that is, we were really supposed to get end_trigger, and never got
3143 	 * one before the EOF.  Can't use the standard "syntax error" return code,
3144 	 * so that parse_stream_outer can distinguish the EOF and exit smoothly. */
3145 	debug_printf("leaving parse_stream (EOF)\n");
3146 	if (end_trigger != '\0') return -1;
3147 	return 0;
3148 }
3149 
3150 static void mapset(const unsigned char *set, int code)
3151 {
3152 	const unsigned char *s;
3153 	for (s=set; *s; s++) map[*s] = code;
3154 }
3155 
3156 static void update_ifs_map(void)
3157 {
3158 	/* char *ifs and char map[256] are both globals. */
3159 	ifs = (uchar *)env_get("IFS");
3160 	if (ifs == NULL) ifs=(uchar *)" \t\n";
3161 	/* Precompute a list of 'flow through' behavior so it can be treated
3162 	 * quickly up front.  Computation is necessary because of IFS.
3163 	 * Special case handling of IFS == " \t\n" is not implemented.
3164 	 * The map[] array only really needs two bits each, and on most machines
3165 	 * that would be faster because of the reduced L1 cache footprint.
3166 	 */
3167 	memset(map,0,sizeof(map)); /* most characters flow through always */
3168 #ifndef __U_BOOT__
3169 	mapset((uchar *)"\\$'\"`", 3);      /* never flow through */
3170 	mapset((uchar *)"<>;&|(){}#", 1);   /* flow through if quoted */
3171 #else
3172 	{
3173 		uchar subst[2] = {SUBSTED_VAR_SYMBOL, 0};
3174 		mapset(subst, 3);       /* never flow through */
3175 	}
3176 	mapset((uchar *)"\\$'\"", 3);       /* never flow through */
3177 	mapset((uchar *)";&|#", 1);         /* flow through if quoted */
3178 #endif
3179 	mapset(ifs, 2);            /* also flow through if quoted */
3180 }
3181 
3182 /* most recursion does not come through here, the exeception is
3183  * from builtin_source() */
3184 static int parse_stream_outer(struct in_str *inp, int flag)
3185 {
3186 
3187 	struct p_context ctx;
3188 	o_string temp=NULL_O_STRING;
3189 	int rcode;
3190 #ifdef __U_BOOT__
3191 	int code = 1;
3192 #endif
3193 	do {
3194 		ctx.type = flag;
3195 		initialize_context(&ctx);
3196 		update_ifs_map();
3197 		if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING)) mapset((uchar *)";$&|", 0);
3198 		inp->promptmode=1;
3199 		rcode = parse_stream(&temp, &ctx, inp,
3200 				     flag & FLAG_CONT_ON_NEWLINE ? -1 : '\n');
3201 #ifdef __U_BOOT__
3202 		if (rcode == 1) flag_repeat = 0;
3203 #endif
3204 		if (rcode != 1 && ctx.old_flag != 0) {
3205 			syntax();
3206 #ifdef __U_BOOT__
3207 			flag_repeat = 0;
3208 #endif
3209 		}
3210 		if (rcode != 1 && ctx.old_flag == 0) {
3211 			done_word(&temp, &ctx);
3212 			done_pipe(&ctx,PIPE_SEQ);
3213 #ifndef __U_BOOT__
3214 			run_list(ctx.list_head);
3215 #else
3216 			code = run_list(ctx.list_head);
3217 			if (code == -2) {	/* exit */
3218 				b_free(&temp);
3219 				code = 0;
3220 				/* XXX hackish way to not allow exit from main loop */
3221 				if (inp->peek == file_peek) {
3222 					printf("exit not allowed from main input shell.\n");
3223 					continue;
3224 				}
3225 				break;
3226 			}
3227 			if (code == -1)
3228 			    flag_repeat = 0;
3229 #endif
3230 		} else {
3231 			if (ctx.old_flag != 0) {
3232 				free(ctx.stack);
3233 				b_reset(&temp);
3234 			}
3235 #ifdef __U_BOOT__
3236 			if (inp->__promptme == 0) printf("<INTERRUPT>\n");
3237 			inp->__promptme = 1;
3238 #endif
3239 			temp.nonnull = 0;
3240 			temp.quote = 0;
3241 			inp->p = NULL;
3242 			free_pipe_list(ctx.list_head,0);
3243 		}
3244 		b_free(&temp);
3245 	/* loop on syntax errors, return on EOF */
3246 	} while (rcode != -1 && !(flag & FLAG_EXIT_FROM_LOOP) &&
3247 		(inp->peek != static_peek || b_peek(inp)));
3248 #ifndef __U_BOOT__
3249 	return 0;
3250 #else
3251 	return (code != 0) ? 1 : 0;
3252 #endif /* __U_BOOT__ */
3253 }
3254 
3255 #ifndef __U_BOOT__
3256 static int parse_string_outer(const char *s, int flag)
3257 #else
3258 int parse_string_outer(const char *s, int flag)
3259 #endif	/* __U_BOOT__ */
3260 {
3261 	struct in_str input;
3262 #ifdef __U_BOOT__
3263 	char *p = NULL;
3264 	int rcode;
3265 	if (!s)
3266 		return 1;
3267 	if (!*s)
3268 		return 0;
3269 	if (!(p = strchr(s, '\n')) || *++p) {
3270 		p = xmalloc(strlen(s) + 2);
3271 		strcpy(p, s);
3272 		strcat(p, "\n");
3273 		setup_string_in_str(&input, p);
3274 		rcode = parse_stream_outer(&input, flag);
3275 		free(p);
3276 		return rcode;
3277 	} else {
3278 #endif
3279 	setup_string_in_str(&input, s);
3280 	return parse_stream_outer(&input, flag);
3281 #ifdef __U_BOOT__
3282 	}
3283 #endif
3284 }
3285 
3286 #ifndef __U_BOOT__
3287 static int parse_file_outer(FILE *f)
3288 #else
3289 int parse_file_outer(void)
3290 #endif
3291 {
3292 	int rcode;
3293 	struct in_str input;
3294 #ifndef __U_BOOT__
3295 	setup_file_in_str(&input, f);
3296 #else
3297 	setup_file_in_str(&input);
3298 #endif
3299 	rcode = parse_stream_outer(&input, FLAG_PARSE_SEMICOLON);
3300 	return rcode;
3301 }
3302 
3303 #ifdef __U_BOOT__
3304 #ifdef CONFIG_NEEDS_MANUAL_RELOC
3305 static void u_boot_hush_reloc(void)
3306 {
3307 	unsigned long addr;
3308 	struct reserved_combo *r;
3309 
3310 	for (r=reserved_list; r<reserved_list+NRES; r++) {
3311 		addr = (ulong) (r->literal) + gd->reloc_off;
3312 		r->literal = (char *)addr;
3313 	}
3314 }
3315 #endif
3316 
3317 int u_boot_hush_start(void)
3318 {
3319 	if (top_vars == NULL) {
3320 		top_vars = malloc(sizeof(struct variables));
3321 		top_vars->name = "HUSH_VERSION";
3322 		top_vars->value = "0.01";
3323 		top_vars->next = NULL;
3324 		top_vars->flg_export = 0;
3325 		top_vars->flg_read_only = 1;
3326 #ifdef CONFIG_NEEDS_MANUAL_RELOC
3327 		u_boot_hush_reloc();
3328 #endif
3329 	}
3330 	return 0;
3331 }
3332 
3333 static void *xmalloc(size_t size)
3334 {
3335 	void *p = NULL;
3336 
3337 	if (!(p = malloc(size))) {
3338 	    printf("ERROR : memory not allocated\n");
3339 	    for(;;);
3340 	}
3341 	return p;
3342 }
3343 
3344 static void *xrealloc(void *ptr, size_t size)
3345 {
3346 	void *p = NULL;
3347 
3348 	if (!(p = realloc(ptr, size))) {
3349 	    printf("ERROR : memory not allocated\n");
3350 	    for(;;);
3351 	}
3352 	return p;
3353 }
3354 #endif /* __U_BOOT__ */
3355 
3356 #ifndef __U_BOOT__
3357 /* Make sure we have a controlling tty.  If we get started under a job
3358  * aware app (like bash for example), make sure we are now in charge so
3359  * we don't fight over who gets the foreground */
3360 static void setup_job_control(void)
3361 {
3362 	static pid_t shell_pgrp;
3363 	/* Loop until we are in the foreground.  */
3364 	while (tcgetpgrp (shell_terminal) != (shell_pgrp = getpgrp ()))
3365 		kill (- shell_pgrp, SIGTTIN);
3366 
3367 	/* Ignore interactive and job-control signals.  */
3368 	signal(SIGINT, SIG_IGN);
3369 	signal(SIGQUIT, SIG_IGN);
3370 	signal(SIGTERM, SIG_IGN);
3371 	signal(SIGTSTP, SIG_IGN);
3372 	signal(SIGTTIN, SIG_IGN);
3373 	signal(SIGTTOU, SIG_IGN);
3374 	signal(SIGCHLD, SIG_IGN);
3375 
3376 	/* Put ourselves in our own process group.  */
3377 	setsid();
3378 	shell_pgrp = getpid ();
3379 	setpgid (shell_pgrp, shell_pgrp);
3380 
3381 	/* Grab control of the terminal.  */
3382 	tcsetpgrp(shell_terminal, shell_pgrp);
3383 }
3384 
3385 int hush_main(int argc, char * const *argv)
3386 {
3387 	int opt;
3388 	FILE *input;
3389 	char **e = environ;
3390 
3391 	/* XXX what should these be while sourcing /etc/profile? */
3392 	global_argc = argc;
3393 	global_argv = argv;
3394 
3395 	/* (re?) initialize globals.  Sometimes hush_main() ends up calling
3396 	 * hush_main(), therefore we cannot rely on the BSS to zero out this
3397 	 * stuff.  Reset these to 0 every time. */
3398 	ifs = NULL;
3399 	/* map[] is taken care of with call to update_ifs_map() */
3400 	fake_mode = 0;
3401 	interactive = 0;
3402 	close_me_head = NULL;
3403 	last_bg_pid = 0;
3404 	job_list = NULL;
3405 	last_jobid = 0;
3406 
3407 	/* Initialize some more globals to non-zero values */
3408 	set_cwd();
3409 #ifdef CONFIG_FEATURE_COMMAND_EDITING
3410 	cmdedit_set_initial_prompt();
3411 #else
3412 	PS1 = NULL;
3413 #endif
3414 	PS2 = "> ";
3415 
3416 	/* initialize our shell local variables with the values
3417 	 * currently living in the environment */
3418 	if (e) {
3419 		for (; *e; e++)
3420 			set_local_var(*e, 2);   /* without call putenv() */
3421 	}
3422 
3423 	last_return_code=EXIT_SUCCESS;
3424 
3425 
3426 	if (argv[0] && argv[0][0] == '-') {
3427 		debug_printf("\nsourcing /etc/profile\n");
3428 		if ((input = fopen("/etc/profile", "r")) != NULL) {
3429 			mark_open(fileno(input));
3430 			parse_file_outer(input);
3431 			mark_closed(fileno(input));
3432 			fclose(input);
3433 		}
3434 	}
3435 	input=stdin;
3436 
3437 	while ((opt = getopt(argc, argv, "c:xif")) > 0) {
3438 		switch (opt) {
3439 			case 'c':
3440 				{
3441 					global_argv = argv+optind;
3442 					global_argc = argc-optind;
3443 					opt = parse_string_outer(optarg, FLAG_PARSE_SEMICOLON);
3444 					goto final_return;
3445 				}
3446 				break;
3447 			case 'i':
3448 				interactive++;
3449 				break;
3450 			case 'f':
3451 				fake_mode++;
3452 				break;
3453 			default:
3454 #ifndef BB_VER
3455 				fprintf(stderr, "Usage: sh [FILE]...\n"
3456 						"   or: sh -c command [args]...\n\n");
3457 				exit(EXIT_FAILURE);
3458 #else
3459 				show_usage();
3460 #endif
3461 		}
3462 	}
3463 	/* A shell is interactive if the `-i' flag was given, or if all of
3464 	 * the following conditions are met:
3465 	 *	  no -c command
3466 	 *    no arguments remaining or the -s flag given
3467 	 *    standard input is a terminal
3468 	 *    standard output is a terminal
3469 	 *    Refer to Posix.2, the description of the `sh' utility. */
3470 	if (argv[optind]==NULL && input==stdin &&
3471 			isatty(fileno(stdin)) && isatty(fileno(stdout))) {
3472 		interactive++;
3473 	}
3474 
3475 	debug_printf("\ninteractive=%d\n", interactive);
3476 	if (interactive) {
3477 		/* Looks like they want an interactive shell */
3478 #ifndef CONFIG_FEATURE_SH_EXTRA_QUIET
3479 		printf( "\n\n" BB_BANNER " hush - the humble shell v0.01 (testing)\n");
3480 		printf( "Enter 'help' for a list of built-in commands.\n\n");
3481 #endif
3482 		setup_job_control();
3483 	}
3484 
3485 	if (argv[optind]==NULL) {
3486 		opt=parse_file_outer(stdin);
3487 		goto final_return;
3488 	}
3489 
3490 	debug_printf("\nrunning script '%s'\n", argv[optind]);
3491 	global_argv = argv+optind;
3492 	global_argc = argc-optind;
3493 	input = xfopen(argv[optind], "r");
3494 	opt = parse_file_outer(input);
3495 
3496 #ifdef CONFIG_FEATURE_CLEAN_UP
3497 	fclose(input);
3498 	if (cwd && cwd != unknown)
3499 		free((char*)cwd);
3500 	{
3501 		struct variables *cur, *tmp;
3502 		for(cur = top_vars; cur; cur = tmp) {
3503 			tmp = cur->next;
3504 			if (!cur->flg_read_only) {
3505 				free(cur->name);
3506 				free(cur->value);
3507 				free(cur);
3508 			}
3509 		}
3510 	}
3511 #endif
3512 
3513 final_return:
3514 	return(opt?opt:last_return_code);
3515 }
3516 #endif
3517 
3518 static char *insert_var_value(char *inp)
3519 {
3520 	return insert_var_value_sub(inp, 0);
3521 }
3522 
3523 static char *insert_var_value_sub(char *inp, int tag_subst)
3524 {
3525 	int res_str_len = 0;
3526 	int len;
3527 	int done = 0;
3528 	char *p, *p1, *res_str = NULL;
3529 
3530 	while ((p = strchr(inp, SPECIAL_VAR_SYMBOL))) {
3531 		/* check the beginning of the string for normal characters */
3532 		if (p != inp) {
3533 			/* copy any characters to the result string */
3534 			len = p - inp;
3535 			res_str = xrealloc(res_str, (res_str_len + len));
3536 			strncpy((res_str + res_str_len), inp, len);
3537 			res_str_len += len;
3538 		}
3539 		inp = ++p;
3540 		/* find the ending marker */
3541 		p = strchr(inp, SPECIAL_VAR_SYMBOL);
3542 		*p = '\0';
3543 		/* look up the value to substitute */
3544 		if ((p1 = lookup_param(inp))) {
3545 			if (tag_subst)
3546 				len = res_str_len + strlen(p1) + 2;
3547 			else
3548 				len = res_str_len + strlen(p1);
3549 			res_str = xrealloc(res_str, (1 + len));
3550 			if (tag_subst) {
3551 				/*
3552 				 * copy the variable value to the result
3553 				 * string
3554 				 */
3555 				strcpy((res_str + res_str_len + 1), p1);
3556 
3557 				/*
3558 				 * mark the replaced text to be accepted as
3559 				 * is
3560 				 */
3561 				res_str[res_str_len] = SUBSTED_VAR_SYMBOL;
3562 				res_str[res_str_len + 1 + strlen(p1)] =
3563 					SUBSTED_VAR_SYMBOL;
3564 			} else
3565 				/*
3566 				 * copy the variable value to the result
3567 				 * string
3568 				 */
3569 				strcpy((res_str + res_str_len), p1);
3570 
3571 			res_str_len = len;
3572 		}
3573 		*p = SPECIAL_VAR_SYMBOL;
3574 		inp = ++p;
3575 		done = 1;
3576 	}
3577 	if (done) {
3578 		res_str = xrealloc(res_str, (1 + res_str_len + strlen(inp)));
3579 		strcpy((res_str + res_str_len), inp);
3580 		while ((p = strchr(res_str, '\n'))) {
3581 			*p = ' ';
3582 		}
3583 	}
3584 	return (res_str == NULL) ? inp : res_str;
3585 }
3586 
3587 static char **make_list_in(char **inp, char *name)
3588 {
3589 	int len, i;
3590 	int name_len = strlen(name);
3591 	int n = 0;
3592 	char **list;
3593 	char *p1, *p2, *p3;
3594 
3595 	/* create list of variable values */
3596 	list = xmalloc(sizeof(*list));
3597 	for (i = 0; inp[i]; i++) {
3598 		p3 = insert_var_value(inp[i]);
3599 		p1 = p3;
3600 		while (*p1) {
3601 			if (*p1 == ' ') {
3602 				p1++;
3603 				continue;
3604 			}
3605 			if ((p2 = strchr(p1, ' '))) {
3606 				len = p2 - p1;
3607 			} else {
3608 				len = strlen(p1);
3609 				p2 = p1 + len;
3610 			}
3611 			/* we use n + 2 in realloc for list,because we add
3612 			 * new element and then we will add NULL element */
3613 			list = xrealloc(list, sizeof(*list) * (n + 2));
3614 			list[n] = xmalloc(2 + name_len + len);
3615 			strcpy(list[n], name);
3616 			strcat(list[n], "=");
3617 			strncat(list[n], p1, len);
3618 			list[n++][name_len + len + 1] = '\0';
3619 			p1 = p2;
3620 		}
3621 		if (p3 != inp[i]) free(p3);
3622 	}
3623 	list[n] = NULL;
3624 	return list;
3625 }
3626 
3627 /*
3628  * Make new string for parser
3629  * inp     - array of argument strings to flatten
3630  * nonnull - indicates argument was quoted when originally parsed
3631  */
3632 static char *make_string(char **inp, int *nonnull)
3633 {
3634 	char *p;
3635 	char *str = NULL;
3636 	int n;
3637 	int len = 2;
3638 	char *noeval_str;
3639 	int noeval = 0;
3640 
3641 	noeval_str = get_local_var("HUSH_NO_EVAL");
3642 	if (noeval_str != NULL && *noeval_str != '0' && *noeval_str != '\0')
3643 		noeval = 1;
3644 	for (n = 0; inp[n]; n++) {
3645 		p = insert_var_value_sub(inp[n], noeval);
3646 		str = xrealloc(str, (len + strlen(p) + (2 * nonnull[n])));
3647 		if (n) {
3648 			strcat(str, " ");
3649 		} else {
3650 			*str = '\0';
3651 		}
3652 		if (nonnull[n])
3653 			strcat(str, "'");
3654 		strcat(str, p);
3655 		if (nonnull[n])
3656 			strcat(str, "'");
3657 		len = strlen(str) + 3;
3658 		if (p != inp[n]) free(p);
3659 	}
3660 	len = strlen(str);
3661 	*(str + len) = '\n';
3662 	*(str + len + 1) = '\0';
3663 	return str;
3664 }
3665 
3666 #ifdef __U_BOOT__
3667 static int do_showvar(cmd_tbl_t *cmdtp, int flag, int argc,
3668 		      char * const argv[])
3669 {
3670 	int i, k;
3671 	int rcode = 0;
3672 	struct variables *cur;
3673 
3674 	if (argc == 1) {		/* Print all env variables	*/
3675 		for (cur = top_vars; cur; cur = cur->next) {
3676 			printf ("%s=%s\n", cur->name, cur->value);
3677 			if (ctrlc ()) {
3678 				puts ("\n ** Abort\n");
3679 				return 1;
3680 			}
3681 		}
3682 		return 0;
3683 	}
3684 	for (i = 1; i < argc; ++i) {	/* print single env variables	*/
3685 		char *name = argv[i];
3686 
3687 		k = -1;
3688 		for (cur = top_vars; cur; cur = cur->next) {
3689 			if(strcmp (cur->name, name) == 0) {
3690 				k = 0;
3691 				printf ("%s=%s\n", cur->name, cur->value);
3692 			}
3693 			if (ctrlc ()) {
3694 				puts ("\n ** Abort\n");
3695 				return 1;
3696 			}
3697 		}
3698 		if (k < 0) {
3699 			printf ("## Error: \"%s\" not defined\n", name);
3700 			rcode ++;
3701 		}
3702 	}
3703 	return rcode;
3704 }
3705 
3706 U_BOOT_CMD(
3707 	showvar, CONFIG_SYS_MAXARGS, 1,	do_showvar,
3708 	"print local hushshell variables",
3709 	"\n    - print values of all hushshell variables\n"
3710 	"showvar name ...\n"
3711 	"    - print value of hushshell variable 'name'"
3712 );
3713 
3714 #endif
3715 /****************************************************************************/
3716