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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 <common.h>         /* readline */
79 #include <env.h>
80 #include <malloc.h>         /* malloc, free, realloc*/
81 #include <linux/ctype.h>    /* isalpha, isdigit */
82 #include <console.h>
83 #include <bootretry.h>
84 #include <cli.h>
85 #include <cli_hush.h>
86 #include <command.h>        /* find_cmd */
87 #ifndef CONFIG_SYS_PROMPT_HUSH_PS2
88 #define CONFIG_SYS_PROMPT_HUSH_PS2	"> "
89 #endif
90 #endif
91 #ifndef __U_BOOT__
92 #include <ctype.h>     /* isalpha, isdigit */
93 #include <unistd.h>    /* getpid */
94 #include <stdlib.h>    /* getenv, atoi */
95 #include <string.h>    /* strchr */
96 #include <stdio.h>     /* popen etc. */
97 #include <glob.h>      /* glob, of course */
98 #include <stdarg.h>    /* va_list */
99 #include <errno.h>
100 #include <fcntl.h>
101 #include <getopt.h>    /* should be pretty obvious */
102 
103 #include <sys/stat.h>  /* ulimit */
104 #include <sys/types.h>
105 #include <sys/wait.h>
106 #include <signal.h>
107 
108 /* #include <dmalloc.h> */
109 
110 #if 1
111 #include "busybox.h"
112 #include "cmdedit.h"
113 #else
114 #define applet_name "hush"
115 #include "standalone.h"
116 #define hush_main main
117 #undef CONFIG_FEATURE_SH_FANCY_PROMPT
118 #define BB_BANNER
119 #endif
120 #endif
121 #define SPECIAL_VAR_SYMBOL 03
122 #define SUBSTED_VAR_SYMBOL 04
123 #ifndef __U_BOOT__
124 #define FLAG_EXIT_FROM_LOOP 1
125 #define FLAG_PARSE_SEMICOLON (1 << 1)		/* symbol ';' is special for parser */
126 #define FLAG_REPARSING       (1 << 2)		/* >= 2nd pass */
127 
128 #endif
129 
130 #ifdef __U_BOOT__
131 DECLARE_GLOBAL_DATA_PTR;
132 
133 #define EXIT_SUCCESS 0
134 #define EOF -1
135 #define syntax() syntax_err()
136 #define xstrdup strdup
137 #define error_msg printf
138 #else
139 typedef enum {
140 	REDIRECT_INPUT     = 1,
141 	REDIRECT_OVERWRITE = 2,
142 	REDIRECT_APPEND    = 3,
143 	REDIRECT_HEREIS    = 4,
144 	REDIRECT_IO        = 5
145 } redir_type;
146 
147 /* The descrip member of this structure is only used to make debugging
148  * output pretty */
149 struct {int mode; int default_fd; char *descrip;} redir_table[] = {
150 	{ 0,                         0, "()" },
151 	{ O_RDONLY,                  0, "<"  },
152 	{ O_CREAT|O_TRUNC|O_WRONLY,  1, ">"  },
153 	{ O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
154 	{ O_RDONLY,                 -1, "<<" },
155 	{ O_RDWR,                    1, "<>" }
156 };
157 #endif
158 
159 typedef enum {
160 	PIPE_SEQ = 1,
161 	PIPE_AND = 2,
162 	PIPE_OR  = 3,
163 	PIPE_BG  = 4,
164 } pipe_style;
165 
166 /* might eventually control execution */
167 typedef enum {
168 	RES_NONE  = 0,
169 	RES_IF    = 1,
170 	RES_THEN  = 2,
171 	RES_ELIF  = 3,
172 	RES_ELSE  = 4,
173 	RES_FI    = 5,
174 	RES_FOR   = 6,
175 	RES_WHILE = 7,
176 	RES_UNTIL = 8,
177 	RES_DO    = 9,
178 	RES_DONE  = 10,
179 	RES_XXXX  = 11,
180 	RES_IN    = 12,
181 	RES_SNTX  = 13
182 } reserved_style;
183 #define FLAG_END   (1<<RES_NONE)
184 #define FLAG_IF    (1<<RES_IF)
185 #define FLAG_THEN  (1<<RES_THEN)
186 #define FLAG_ELIF  (1<<RES_ELIF)
187 #define FLAG_ELSE  (1<<RES_ELSE)
188 #define FLAG_FI    (1<<RES_FI)
189 #define FLAG_FOR   (1<<RES_FOR)
190 #define FLAG_WHILE (1<<RES_WHILE)
191 #define FLAG_UNTIL (1<<RES_UNTIL)
192 #define FLAG_DO    (1<<RES_DO)
193 #define FLAG_DONE  (1<<RES_DONE)
194 #define FLAG_IN    (1<<RES_IN)
195 #define FLAG_START (1<<RES_XXXX)
196 
197 /* This holds pointers to the various results of parsing */
198 struct p_context {
199 	struct child_prog *child;
200 	struct pipe *list_head;
201 	struct pipe *pipe;
202 #ifndef __U_BOOT__
203 	struct redir_struct *pending_redirect;
204 #endif
205 	reserved_style w;
206 	int old_flag;				/* for figuring out valid reserved words */
207 	struct p_context *stack;
208 	int type;			/* define type of parser : ";$" common or special symbol */
209 	/* How about quoting status? */
210 };
211 
212 #ifndef __U_BOOT__
213 struct redir_struct {
214 	redir_type type;			/* type of redirection */
215 	int fd;						/* file descriptor being redirected */
216 	int dup;					/* -1, or file descriptor being duplicated */
217 	struct redir_struct *next;	/* pointer to the next redirect in the list */
218 	glob_t word;				/* *word.gl_pathv is the filename */
219 };
220 #endif
221 
222 struct child_prog {
223 #ifndef __U_BOOT__
224 	pid_t pid;					/* 0 if exited */
225 #endif
226 	char **argv;				/* program name and arguments */
227 	/* was quoted when parsed; copy of struct o_string.nonnull field */
228 	int *argv_nonnull;
229 #ifdef __U_BOOT__
230 	int    argc;                            /* number of program arguments */
231 #endif
232 	struct pipe *group;			/* if non-NULL, first in group or subshell */
233 #ifndef __U_BOOT__
234 	int subshell;				/* flag, non-zero if group must be forked */
235 	struct redir_struct *redirects;	/* I/O redirections */
236 	glob_t glob_result;			/* result of parameter globbing */
237 	int is_stopped;				/* is the program currently running? */
238 	struct pipe *family;		/* pointer back to the child's parent pipe */
239 #endif
240 	int sp;				/* number of SPECIAL_VAR_SYMBOL */
241 	int type;
242 };
243 
244 struct pipe {
245 #ifndef __U_BOOT__
246 	int jobid;					/* job number */
247 #endif
248 	int num_progs;				/* total number of programs in job */
249 #ifndef __U_BOOT__
250 	int running_progs;			/* number of programs running */
251 	char *text;					/* name of job */
252 	char *cmdbuf;				/* buffer various argv's point into */
253 	pid_t pgrp;					/* process group ID for the job */
254 #endif
255 	struct child_prog *progs;	/* array of commands in pipe */
256 	struct pipe *next;			/* to track background commands */
257 #ifndef __U_BOOT__
258 	int stopped_progs;			/* number of programs alive, but stopped */
259 	int job_context;			/* bitmask defining current context */
260 #endif
261 	pipe_style followup;		/* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
262 	reserved_style r_mode;		/* supports if, for, while, until */
263 };
264 
265 #ifndef __U_BOOT__
266 struct close_me {
267 	int fd;
268 	struct close_me *next;
269 };
270 #endif
271 
272 struct variables {
273 	char *name;
274 	char *value;
275 	int flg_export;
276 	int flg_read_only;
277 	struct variables *next;
278 };
279 
280 /* globals, connect us to the outside world
281  * the first three support $?, $#, and $1 */
282 #ifndef __U_BOOT__
283 char **global_argv;
284 unsigned int global_argc;
285 #endif
286 static unsigned int last_return_code;
287 #ifndef __U_BOOT__
288 extern char **environ; /* This is in <unistd.h>, but protected with __USE_GNU */
289 #endif
290 
291 /* "globals" within this file */
292 static uchar *ifs;
293 static char map[256];
294 #ifndef __U_BOOT__
295 static int fake_mode;
296 static int interactive;
297 static struct close_me *close_me_head;
298 static const char *cwd;
299 static struct pipe *job_list;
300 static unsigned int last_bg_pid;
301 static unsigned int last_jobid;
302 static unsigned int shell_terminal;
303 static char *PS1;
304 static char *PS2;
305 struct variables shell_ver = { "HUSH_VERSION", "0.01", 1, 1, 0 };
306 struct variables *top_vars = &shell_ver;
307 #else
308 static int flag_repeat = 0;
309 static int do_repeat = 0;
310 static struct variables *top_vars = NULL ;
311 #endif /*__U_BOOT__ */
312 
313 #define B_CHUNK (100)
314 #define B_NOSPAC 1
315 
316 typedef struct {
317 	char *data;
318 	int length;
319 	int maxlen;
320 	int quote;
321 	int nonnull;
322 } o_string;
323 #define NULL_O_STRING {NULL,0,0,0,0}
324 /* used for initialization:
325 	o_string foo = NULL_O_STRING; */
326 
327 /* I can almost use ordinary FILE *.  Is open_memstream() universally
328  * available?  Where is it documented? */
329 struct in_str {
330 	const char *p;
331 #ifndef __U_BOOT__
332 	char peek_buf[2];
333 #endif
334 	int __promptme;
335 	int promptmode;
336 #ifndef __U_BOOT__
337 	FILE *file;
338 #endif
339 	int (*get) (struct in_str *);
340 	int (*peek) (struct in_str *);
341 };
342 #define b_getch(input) ((input)->get(input))
343 #define b_peek(input) ((input)->peek(input))
344 
345 #ifndef __U_BOOT__
346 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
347 
348 struct built_in_command {
349 	char *cmd;					/* name */
350 	char *descr;				/* description */
351 	int (*function) (struct child_prog *);	/* function ptr */
352 };
353 #endif
354 
355 /* define DEBUG_SHELL for debugging output (obviously ;-)) */
356 #if 0
357 #define DEBUG_SHELL
358 #endif
359 
360 /* This should be in utility.c */
361 #ifdef DEBUG_SHELL
362 #ifndef __U_BOOT__
debug_printf(const char * format,...)363 static void debug_printf(const char *format, ...)
364 {
365 	va_list args;
366 	va_start(args, format);
367 	vfprintf(stderr, format, args);
368 	va_end(args);
369 }
370 #else
371 #define debug_printf(fmt,args...)	printf (fmt ,##args)
372 #endif
373 #else
debug_printf(const char * format,...)374 static inline void debug_printf(const char *format, ...) { }
375 #endif
376 #define final_printf debug_printf
377 
378 #ifdef __U_BOOT__
syntax_err(void)379 static void syntax_err(void) {
380 	 printf("syntax error\n");
381 }
382 #else
__syntax(char * file,int line)383 static void __syntax(char *file, int line) {
384 	error_msg("syntax error %s:%d", file, line);
385 }
386 #define syntax() __syntax(__FILE__, __LINE__)
387 #endif
388 
389 #ifdef __U_BOOT__
390 static void *xmalloc(size_t size);
391 static void *xrealloc(void *ptr, size_t size);
392 #else
393 /* Index of subroutines: */
394 /*   function prototypes for builtins */
395 static int builtin_cd(struct child_prog *child);
396 static int builtin_env(struct child_prog *child);
397 static int builtin_eval(struct child_prog *child);
398 static int builtin_exec(struct child_prog *child);
399 static int builtin_exit(struct child_prog *child);
400 static int builtin_export(struct child_prog *child);
401 static int builtin_fg_bg(struct child_prog *child);
402 static int builtin_help(struct child_prog *child);
403 static int builtin_jobs(struct child_prog *child);
404 static int builtin_pwd(struct child_prog *child);
405 static int builtin_read(struct child_prog *child);
406 static int builtin_set(struct child_prog *child);
407 static int builtin_shift(struct child_prog *child);
408 static int builtin_source(struct child_prog *child);
409 static int builtin_umask(struct child_prog *child);
410 static int builtin_unset(struct child_prog *child);
411 static int builtin_not_written(struct child_prog *child);
412 #endif
413 /*   o_string manipulation: */
414 static int b_check_space(o_string *o, int len);
415 static int b_addchr(o_string *o, int ch);
416 static void b_reset(o_string *o);
417 static int b_addqchr(o_string *o, int ch, int quote);
418 #ifndef __U_BOOT__
419 static int b_adduint(o_string *o, unsigned int i);
420 #endif
421 /*  in_str manipulations: */
422 static int static_get(struct in_str *i);
423 static int static_peek(struct in_str *i);
424 static int file_get(struct in_str *i);
425 static int file_peek(struct in_str *i);
426 #ifndef __U_BOOT__
427 static void setup_file_in_str(struct in_str *i, FILE *f);
428 #else
429 static void setup_file_in_str(struct in_str *i);
430 #endif
431 static void setup_string_in_str(struct in_str *i, const char *s);
432 #ifndef __U_BOOT__
433 /*  close_me manipulations: */
434 static void mark_open(int fd);
435 static void mark_closed(int fd);
436 static void close_all(void);
437 #endif
438 /*  "run" the final data structures: */
439 static char *indenter(int i);
440 static int free_pipe_list(struct pipe *head, int indent);
441 static int free_pipe(struct pipe *pi, int indent);
442 /*  really run the final data structures: */
443 #ifndef __U_BOOT__
444 static int setup_redirects(struct child_prog *prog, int squirrel[]);
445 #endif
446 static int run_list_real(struct pipe *pi);
447 #ifndef __U_BOOT__
448 static void pseudo_exec(struct child_prog *child) __attribute__ ((noreturn));
449 #endif
450 static int run_pipe_real(struct pipe *pi);
451 /*   extended glob support: */
452 #ifndef __U_BOOT__
453 static int globhack(const char *src, int flags, glob_t *pglob);
454 static int glob_needed(const char *s);
455 static int xglob(o_string *dest, int flags, glob_t *pglob);
456 #endif
457 /*   variable assignment: */
458 static int is_assignment(const char *s);
459 /*   data structure manipulation: */
460 #ifndef __U_BOOT__
461 static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
462 #endif
463 static void initialize_context(struct p_context *ctx);
464 static int done_word(o_string *dest, struct p_context *ctx);
465 static int done_command(struct p_context *ctx);
466 static int done_pipe(struct p_context *ctx, pipe_style type);
467 /*   primary string parsing: */
468 #ifndef __U_BOOT__
469 static int redirect_dup_num(struct in_str *input);
470 static int redirect_opt_num(o_string *o);
471 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end);
472 static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch);
473 #endif
474 static char *lookup_param(char *src);
475 static char *make_string(char **inp, int *nonnull);
476 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input);
477 #ifndef __U_BOOT__
478 static int parse_string(o_string *dest, struct p_context *ctx, const char *src);
479 #endif
480 static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, int end_trigger);
481 /*   setup: */
482 static int parse_stream_outer(struct in_str *inp, int flag);
483 #ifndef __U_BOOT__
484 static int parse_string_outer(const char *s, int flag);
485 static int parse_file_outer(FILE *f);
486 #endif
487 #ifndef __U_BOOT__
488 /*   job management: */
489 static int checkjobs(struct pipe* fg_pipe);
490 static void insert_bg_job(struct pipe *pi);
491 static void remove_bg_job(struct pipe *pi);
492 #endif
493 /*     local variable support */
494 static char **make_list_in(char **inp, char *name);
495 static char *insert_var_value(char *inp);
496 static char *insert_var_value_sub(char *inp, int tag_subst);
497 
498 #ifndef __U_BOOT__
499 /* Table of built-in functions.  They can be forked or not, depending on
500  * context: within pipes, they fork.  As simple commands, they do not.
501  * When used in non-forking context, they can change global variables
502  * in the parent shell process.  If forked, of course they can not.
503  * For example, 'unset foo | whatever' will parse and run, but foo will
504  * still be set at the end. */
505 static struct built_in_command bltins[] = {
506 	{"bg", "Resume a job in the background", builtin_fg_bg},
507 	{"break", "Exit for, while or until loop", builtin_not_written},
508 	{"cd", "Change working directory", builtin_cd},
509 	{"continue", "Continue for, while or until loop", builtin_not_written},
510 	{"env", "Print all environment variables", builtin_env},
511 	{"eval", "Construct and run shell command", builtin_eval},
512 	{"exec", "Exec command, replacing this shell with the exec'd process",
513 		builtin_exec},
514 	{"exit", "Exit from shell()", builtin_exit},
515 	{"export", "Set environment variable", builtin_export},
516 	{"fg", "Bring job into the foreground", builtin_fg_bg},
517 	{"jobs", "Lists the active jobs", builtin_jobs},
518 	{"pwd", "Print current directory", builtin_pwd},
519 	{"read", "Input environment variable", builtin_read},
520 	{"return", "Return from a function", builtin_not_written},
521 	{"set", "Set/unset shell local variables", builtin_set},
522 	{"shift", "Shift positional parameters", builtin_shift},
523 	{"trap", "Trap signals", builtin_not_written},
524 	{"ulimit","Controls resource limits", builtin_not_written},
525 	{"umask","Sets file creation mask", builtin_umask},
526 	{"unset", "Unset environment variable", builtin_unset},
527 	{".", "Source-in and run commands in a file", builtin_source},
528 	{"help", "List shell built-in commands", builtin_help},
529 	{NULL, NULL, NULL}
530 };
531 
set_cwd(void)532 static const char *set_cwd(void)
533 {
534 	if(cwd==unknown)
535 		cwd = NULL;     /* xgetcwd(arg) called free(arg) */
536 	cwd = xgetcwd((char *)cwd);
537 	if (!cwd)
538 		cwd = unknown;
539 	return cwd;
540 }
541 
542 /* built-in 'eval' handler */
builtin_eval(struct child_prog * child)543 static int builtin_eval(struct child_prog *child)
544 {
545 	char *str = NULL;
546 	int rcode = EXIT_SUCCESS;
547 
548 	if (child->argv[1]) {
549 		str = make_string(child->argv + 1);
550 		parse_string_outer(str, FLAG_EXIT_FROM_LOOP |
551 					FLAG_PARSE_SEMICOLON);
552 		free(str);
553 		rcode = last_return_code;
554 	}
555 	return rcode;
556 }
557 
558 /* built-in 'cd <path>' handler */
builtin_cd(struct child_prog * child)559 static int builtin_cd(struct child_prog *child)
560 {
561 	char *newdir;
562 	if (child->argv[1] == NULL)
563 		newdir = env_get("HOME");
564 	else
565 		newdir = child->argv[1];
566 	if (chdir(newdir)) {
567 		printf("cd: %s: %s\n", newdir, strerror(errno));
568 		return EXIT_FAILURE;
569 	}
570 	set_cwd();
571 	return EXIT_SUCCESS;
572 }
573 
574 /* built-in 'env' handler */
builtin_env(struct child_prog * dummy)575 static int builtin_env(struct child_prog *dummy)
576 {
577 	char **e = environ;
578 	if (e == NULL) return EXIT_FAILURE;
579 	for (; *e; e++) {
580 		puts(*e);
581 	}
582 	return EXIT_SUCCESS;
583 }
584 
585 /* built-in 'exec' handler */
builtin_exec(struct child_prog * child)586 static int builtin_exec(struct child_prog *child)
587 {
588 	if (child->argv[1] == NULL)
589 		return EXIT_SUCCESS;   /* Really? */
590 	child->argv++;
591 	pseudo_exec(child);
592 	/* never returns */
593 }
594 
595 /* built-in 'exit' handler */
builtin_exit(struct child_prog * child)596 static int builtin_exit(struct child_prog *child)
597 {
598 	if (child->argv[1] == NULL)
599 		exit(last_return_code);
600 	exit (atoi(child->argv[1]));
601 }
602 
603 /* built-in 'export VAR=value' handler */
builtin_export(struct child_prog * child)604 static int builtin_export(struct child_prog *child)
605 {
606 	int res = 0;
607 	char *name = child->argv[1];
608 
609 	if (name == NULL) {
610 		return (builtin_env(child));
611 	}
612 
613 	name = strdup(name);
614 
615 	if(name) {
616 		char *value = strchr(name, '=');
617 
618 		if (!value) {
619 			char *tmp;
620 			/* They are exporting something without an =VALUE */
621 
622 			value = get_local_var(name);
623 			if (value) {
624 				size_t ln = strlen(name);
625 
626 				tmp = realloc(name, ln+strlen(value)+2);
627 				if(tmp==NULL)
628 					res = -1;
629 				else {
630 					sprintf(tmp+ln, "=%s", value);
631 					name = tmp;
632 				}
633 			} else {
634 				/* bash does not return an error when trying to export
635 				 * an undefined variable.  Do likewise. */
636 				res = 1;
637 			}
638 		}
639 	}
640 	if (res<0)
641 		perror_msg("export");
642 	else if(res==0)
643 		res = set_local_var(name, 1);
644 	else
645 		res = 0;
646 	free(name);
647 	return res;
648 }
649 
650 /* built-in 'fg' and 'bg' handler */
builtin_fg_bg(struct child_prog * child)651 static int builtin_fg_bg(struct child_prog *child)
652 {
653 	int i, jobnum;
654 	struct pipe *pi=NULL;
655 
656 	if (!interactive)
657 		return EXIT_FAILURE;
658 	/* If they gave us no args, assume they want the last backgrounded task */
659 	if (!child->argv[1]) {
660 		for (pi = job_list; pi; pi = pi->next) {
661 			if (pi->jobid == last_jobid) {
662 				break;
663 			}
664 		}
665 		if (!pi) {
666 			error_msg("%s: no current job", child->argv[0]);
667 			return EXIT_FAILURE;
668 		}
669 	} else {
670 		if (sscanf(child->argv[1], "%%%d", &jobnum) != 1) {
671 			error_msg("%s: bad argument '%s'", child->argv[0], child->argv[1]);
672 			return EXIT_FAILURE;
673 		}
674 		for (pi = job_list; pi; pi = pi->next) {
675 			if (pi->jobid == jobnum) {
676 				break;
677 			}
678 		}
679 		if (!pi) {
680 			error_msg("%s: %d: no such job", child->argv[0], jobnum);
681 			return EXIT_FAILURE;
682 		}
683 	}
684 
685 	if (*child->argv[0] == 'f') {
686 		/* Put the job into the foreground.  */
687 		tcsetpgrp(shell_terminal, pi->pgrp);
688 	}
689 
690 	/* Restart the processes in the job */
691 	for (i = 0; i < pi->num_progs; i++)
692 		pi->progs[i].is_stopped = 0;
693 
694 	if ( (i=kill(- pi->pgrp, SIGCONT)) < 0) {
695 		if (i == ESRCH) {
696 			remove_bg_job(pi);
697 		} else {
698 			perror_msg("kill (SIGCONT)");
699 		}
700 	}
701 
702 	pi->stopped_progs = 0;
703 	return EXIT_SUCCESS;
704 }
705 
706 /* built-in 'help' handler */
builtin_help(struct child_prog * dummy)707 static int builtin_help(struct child_prog *dummy)
708 {
709 	struct built_in_command *x;
710 
711 	printf("\nBuilt-in commands:\n");
712 	printf("-------------------\n");
713 	for (x = bltins; x->cmd; x++) {
714 		if (x->descr==NULL)
715 			continue;
716 		printf("%s\t%s\n", x->cmd, x->descr);
717 	}
718 	printf("\n\n");
719 	return EXIT_SUCCESS;
720 }
721 
722 /* built-in 'jobs' handler */
builtin_jobs(struct child_prog * child)723 static int builtin_jobs(struct child_prog *child)
724 {
725 	struct pipe *job;
726 	char *status_string;
727 
728 	for (job = job_list; job; job = job->next) {
729 		if (job->running_progs == job->stopped_progs)
730 			status_string = "Stopped";
731 		else
732 			status_string = "Running";
733 
734 		printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->text);
735 	}
736 	return EXIT_SUCCESS;
737 }
738 
739 
740 /* built-in 'pwd' handler */
builtin_pwd(struct child_prog * dummy)741 static int builtin_pwd(struct child_prog *dummy)
742 {
743 	puts(set_cwd());
744 	return EXIT_SUCCESS;
745 }
746 
747 /* built-in 'read VAR' handler */
builtin_read(struct child_prog * child)748 static int builtin_read(struct child_prog *child)
749 {
750 	int res;
751 
752 	if (child->argv[1]) {
753 		char string[BUFSIZ];
754 		char *var = 0;
755 
756 		string[0] = 0;  /* In case stdin has only EOF */
757 		/* read string */
758 		fgets(string, sizeof(string), stdin);
759 		chomp(string);
760 		var = malloc(strlen(child->argv[1])+strlen(string)+2);
761 		if(var) {
762 			sprintf(var, "%s=%s", child->argv[1], string);
763 			res = set_local_var(var, 0);
764 		} else
765 			res = -1;
766 		if (res)
767 			fprintf(stderr, "read: %m\n");
768 		free(var);      /* So not move up to avoid breaking errno */
769 		return res;
770 	} else {
771 		do res=getchar(); while(res!='\n' && res!=EOF);
772 		return 0;
773 	}
774 }
775 
776 /* built-in 'set VAR=value' handler */
builtin_set(struct child_prog * child)777 static int builtin_set(struct child_prog *child)
778 {
779 	char *temp = child->argv[1];
780 	struct variables *e;
781 
782 	if (temp == NULL)
783 		for(e = top_vars; e; e=e->next)
784 			printf("%s=%s\n", e->name, e->value);
785 	else
786 		set_local_var(temp, 0);
787 
788 		return EXIT_SUCCESS;
789 }
790 
791 
792 /* Built-in 'shift' handler */
builtin_shift(struct child_prog * child)793 static int builtin_shift(struct child_prog *child)
794 {
795 	int n=1;
796 	if (child->argv[1]) {
797 		n=atoi(child->argv[1]);
798 	}
799 	if (n>=0 && n<global_argc) {
800 		/* XXX This probably breaks $0 */
801 		global_argc -= n;
802 		global_argv += n;
803 		return EXIT_SUCCESS;
804 	} else {
805 		return EXIT_FAILURE;
806 	}
807 }
808 
809 /* Built-in '.' handler (read-in and execute commands from file) */
builtin_source(struct child_prog * child)810 static int builtin_source(struct child_prog *child)
811 {
812 	FILE *input;
813 	int status;
814 
815 	if (child->argv[1] == NULL)
816 		return EXIT_FAILURE;
817 
818 	/* XXX search through $PATH is missing */
819 	input = fopen(child->argv[1], "r");
820 	if (!input) {
821 		error_msg("Couldn't open file '%s'", child->argv[1]);
822 		return EXIT_FAILURE;
823 	}
824 
825 	/* Now run the file */
826 	/* XXX argv and argc are broken; need to save old global_argv
827 	 * (pointer only is OK!) on this stack frame,
828 	 * set global_argv=child->argv+1, recurse, and restore. */
829 	mark_open(fileno(input));
830 	status = parse_file_outer(input);
831 	mark_closed(fileno(input));
832 	fclose(input);
833 	return (status);
834 }
835 
builtin_umask(struct child_prog * child)836 static int builtin_umask(struct child_prog *child)
837 {
838 	mode_t new_umask;
839 	const char *arg = child->argv[1];
840 	char *end;
841 	if (arg) {
842 		new_umask=strtoul(arg, &end, 8);
843 		if (*end!='\0' || end == arg) {
844 			return EXIT_FAILURE;
845 		}
846 	} else {
847 		printf("%.3o\n", (unsigned int) (new_umask=umask(0)));
848 	}
849 	umask(new_umask);
850 	return EXIT_SUCCESS;
851 }
852 
853 /* built-in 'unset VAR' handler */
builtin_unset(struct child_prog * child)854 static int builtin_unset(struct child_prog *child)
855 {
856 	/* bash returned already true */
857 	unset_local_var(child->argv[1]);
858 	return EXIT_SUCCESS;
859 }
860 
builtin_not_written(struct child_prog * child)861 static int builtin_not_written(struct child_prog *child)
862 {
863 	printf("builtin_%s not written\n",child->argv[0]);
864 	return EXIT_FAILURE;
865 }
866 #endif
867 
b_check_space(o_string * o,int len)868 static int b_check_space(o_string *o, int len)
869 {
870 	/* It would be easy to drop a more restrictive policy
871 	 * in here, such as setting a maximum string length */
872 	if (o->length + len > o->maxlen) {
873 		char *old_data = o->data;
874 		/* assert (data == NULL || o->maxlen != 0); */
875 		o->maxlen += max(2*len, B_CHUNK);
876 		o->data = realloc(o->data, 1 + o->maxlen);
877 		if (o->data == NULL) {
878 			free(old_data);
879 		}
880 	}
881 	return o->data == NULL;
882 }
883 
b_addchr(o_string * o,int ch)884 static int b_addchr(o_string *o, int ch)
885 {
886 	debug_printf("b_addchr: %c %d %p\n", ch, o->length, o);
887 	if (b_check_space(o, 1)) return B_NOSPAC;
888 	o->data[o->length] = ch;
889 	o->length++;
890 	o->data[o->length] = '\0';
891 	return 0;
892 }
893 
b_reset(o_string * o)894 static void b_reset(o_string *o)
895 {
896 	o->length = 0;
897 	o->nonnull = 0;
898 	if (o->data != NULL) *o->data = '\0';
899 }
900 
b_free(o_string * o)901 static void b_free(o_string *o)
902 {
903 	b_reset(o);
904 	free(o->data);
905 	o->data = NULL;
906 	o->maxlen = 0;
907 }
908 
909 /* My analysis of quoting semantics tells me that state information
910  * is associated with a destination, not a source.
911  */
b_addqchr(o_string * o,int ch,int quote)912 static int b_addqchr(o_string *o, int ch, int quote)
913 {
914 	if (quote && strchr("*?[\\",ch)) {
915 		int rc;
916 		rc = b_addchr(o, '\\');
917 		if (rc) return rc;
918 	}
919 	return b_addchr(o, ch);
920 }
921 
922 #ifndef __U_BOOT__
b_adduint(o_string * o,unsigned int i)923 static int b_adduint(o_string *o, unsigned int i)
924 {
925 	int r;
926 	char *p = simple_itoa(i);
927 	/* no escape checking necessary */
928 	do r=b_addchr(o, *p++); while (r==0 && *p);
929 	return r;
930 }
931 #endif
932 
static_get(struct in_str * i)933 static int static_get(struct in_str *i)
934 {
935 	int ch = *i->p++;
936 	if (ch=='\0') return EOF;
937 	return ch;
938 }
939 
static_peek(struct in_str * i)940 static int static_peek(struct in_str *i)
941 {
942 	return *i->p;
943 }
944 
945 #ifndef __U_BOOT__
cmdedit_set_initial_prompt(void)946 static inline void cmdedit_set_initial_prompt(void)
947 {
948 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
949 	PS1 = NULL;
950 #else
951 	PS1 = env_get("PS1");
952 	if(PS1==0)
953 		PS1 = "\\w \\$ ";
954 #endif
955 }
956 
setup_prompt_string(int promptmode,char ** prompt_str)957 static inline void setup_prompt_string(int promptmode, char **prompt_str)
958 {
959 	debug_printf("setup_prompt_string %d ",promptmode);
960 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
961 	/* Set up the prompt */
962 	if (promptmode == 1) {
963 		free(PS1);
964 		PS1=xmalloc(strlen(cwd)+4);
965 		sprintf(PS1, "%s %s", cwd, ( geteuid() != 0 ) ?  "$ ":"# ");
966 		*prompt_str = PS1;
967 	} else {
968 		*prompt_str = PS2;
969 	}
970 #else
971 	*prompt_str = (promptmode==1)? PS1 : PS2;
972 #endif
973 	debug_printf("result %s\n",*prompt_str);
974 }
975 #endif
976 
977 #ifdef __U_BOOT__
uboot_cli_readline(struct in_str * i)978 static int uboot_cli_readline(struct in_str *i)
979 {
980 	char *prompt;
981 	char __maybe_unused *ps_prompt = NULL;
982 
983 	if (i->promptmode == 1)
984 		prompt = CONFIG_SYS_PROMPT;
985 	else
986 		prompt = CONFIG_SYS_PROMPT_HUSH_PS2;
987 
988 #ifdef CONFIG_CMDLINE_PS_SUPPORT
989 	if (i->promptmode == 1)
990 		ps_prompt = env_get("PS1");
991 	else
992 		ps_prompt = env_get("PS2");
993 	if (ps_prompt)
994 		prompt = ps_prompt;
995 #endif
996 
997 	return cli_readline(prompt);
998 }
999 #endif
1000 
get_user_input(struct in_str * i)1001 static void get_user_input(struct in_str *i)
1002 {
1003 #ifndef __U_BOOT__
1004 	char *prompt_str;
1005 	static char the_command[BUFSIZ];
1006 
1007 	setup_prompt_string(i->promptmode, &prompt_str);
1008 #ifdef CONFIG_FEATURE_COMMAND_EDITING
1009 	/*
1010 	 ** enable command line editing only while a command line
1011 	 ** is actually being read; otherwise, we'll end up bequeathing
1012 	 ** atexit() handlers and other unwanted stuff to our
1013 	 ** child processes (rob@sysgo.de)
1014 	 */
1015 	cmdedit_read_input(prompt_str, the_command);
1016 #else
1017 	fputs(prompt_str, stdout);
1018 	fflush(stdout);
1019 	the_command[0]=fgetc(i->file);
1020 	the_command[1]='\0';
1021 #endif
1022 	fflush(stdout);
1023 	i->p = the_command;
1024 #else
1025 	int n;
1026 	static char the_command[CONFIG_SYS_CBSIZE + 1];
1027 
1028 	bootretry_reset_cmd_timeout();
1029 	i->__promptme = 1;
1030 	n = uboot_cli_readline(i);
1031 
1032 #ifdef CONFIG_BOOT_RETRY_TIME
1033 	if (n == -2) {
1034 	  puts("\nTimeout waiting for command\n");
1035 #  ifdef CONFIG_RESET_TO_RETRY
1036 	  do_reset(NULL, 0, 0, NULL);
1037 #  else
1038 #	error "This currently only works with CONFIG_RESET_TO_RETRY enabled"
1039 #  endif
1040 	}
1041 #endif
1042 	if (n == -1 ) {
1043 		flag_repeat = 0;
1044 		i->__promptme = 0;
1045 	} else if (n == -3) {
1046 		flag_repeat = 0;
1047 	}
1048 	n = strlen(console_buffer);
1049 	console_buffer[n] = '\n';
1050 	console_buffer[n+1]= '\0';
1051 	if (had_ctrlc()) flag_repeat = 0;
1052 	clear_ctrlc();
1053 	do_repeat = 0;
1054 	if (i->promptmode == 1) {
1055 		if (console_buffer[0] == '\n'&& flag_repeat == 0) {
1056 			strcpy(the_command,console_buffer);
1057 		}
1058 		else {
1059 			if (console_buffer[0] != '\n') {
1060 				strcpy(the_command,console_buffer);
1061 				flag_repeat = 1;
1062 			}
1063 			else {
1064 				do_repeat = 1;
1065 			}
1066 		}
1067 		i->p = the_command;
1068 	}
1069 	else {
1070 		if (console_buffer[0] != '\n') {
1071 			if (strlen(the_command) + strlen(console_buffer)
1072 			    < CONFIG_SYS_CBSIZE) {
1073 				n = strlen(the_command);
1074 				the_command[n-1] = ' ';
1075 				strcpy(&the_command[n],console_buffer);
1076 			}
1077 			else {
1078 				the_command[0] = '\n';
1079 				the_command[1] = '\0';
1080 				flag_repeat = 0;
1081 			}
1082 		}
1083 		if (i->__promptme == 0) {
1084 			the_command[0] = '\n';
1085 			the_command[1] = '\0';
1086 		}
1087 		i->p = console_buffer;
1088 	}
1089 #endif
1090 }
1091 
1092 /* This is the magic location that prints prompts
1093  * and gets data back from the user */
file_get(struct in_str * i)1094 static int file_get(struct in_str *i)
1095 {
1096 	int ch;
1097 
1098 	ch = 0;
1099 	/* If there is data waiting, eat it up */
1100 	if (i->p && *i->p) {
1101 		ch = *i->p++;
1102 	} else {
1103 		/* need to double check i->file because we might be doing something
1104 		 * more complicated by now, like sourcing or substituting. */
1105 #ifndef __U_BOOT__
1106 		if (i->__promptme && interactive && i->file == stdin) {
1107 			while(! i->p || (interactive && strlen(i->p)==0) ) {
1108 #else
1109 			while(! i->p  || strlen(i->p)==0 ) {
1110 #endif
1111 				get_user_input(i);
1112 			}
1113 			i->promptmode=2;
1114 #ifndef __U_BOOT__
1115 			i->__promptme = 0;
1116 #endif
1117 			if (i->p && *i->p) {
1118 				ch = *i->p++;
1119 			}
1120 #ifndef __U_BOOT__
1121 		} else {
1122 			ch = fgetc(i->file);
1123 		}
1124 
1125 #endif
1126 		debug_printf("b_getch: got a %d\n", ch);
1127 	}
1128 #ifndef __U_BOOT__
1129 	if (ch == '\n') i->__promptme=1;
1130 #endif
1131 	return ch;
1132 }
1133 
1134 /* All the callers guarantee this routine will never be
1135  * used right after a newline, so prompting is not needed.
1136  */
1137 static int file_peek(struct in_str *i)
1138 {
1139 #ifndef __U_BOOT__
1140 	if (i->p && *i->p) {
1141 #endif
1142 		return *i->p;
1143 #ifndef __U_BOOT__
1144 	} else {
1145 		i->peek_buf[0] = fgetc(i->file);
1146 		i->peek_buf[1] = '\0';
1147 		i->p = i->peek_buf;
1148 		debug_printf("b_peek: got a %d\n", *i->p);
1149 		return *i->p;
1150 	}
1151 #endif
1152 }
1153 
1154 #ifndef __U_BOOT__
1155 static void setup_file_in_str(struct in_str *i, FILE *f)
1156 #else
1157 static void setup_file_in_str(struct in_str *i)
1158 #endif
1159 {
1160 	i->peek = file_peek;
1161 	i->get = file_get;
1162 	i->__promptme=1;
1163 	i->promptmode=1;
1164 #ifndef __U_BOOT__
1165 	i->file = f;
1166 #endif
1167 	i->p = NULL;
1168 }
1169 
1170 static void setup_string_in_str(struct in_str *i, const char *s)
1171 {
1172 	i->peek = static_peek;
1173 	i->get = static_get;
1174 	i->__promptme=1;
1175 	i->promptmode=1;
1176 	i->p = s;
1177 }
1178 
1179 #ifndef __U_BOOT__
1180 static void mark_open(int fd)
1181 {
1182 	struct close_me *new = xmalloc(sizeof(struct close_me));
1183 	new->fd = fd;
1184 	new->next = close_me_head;
1185 	close_me_head = new;
1186 }
1187 
1188 static void mark_closed(int fd)
1189 {
1190 	struct close_me *tmp;
1191 	if (close_me_head == NULL || close_me_head->fd != fd)
1192 		error_msg_and_die("corrupt close_me");
1193 	tmp = close_me_head;
1194 	close_me_head = close_me_head->next;
1195 	free(tmp);
1196 }
1197 
1198 static void close_all(void)
1199 {
1200 	struct close_me *c;
1201 	for (c=close_me_head; c; c=c->next) {
1202 		close(c->fd);
1203 	}
1204 	close_me_head = NULL;
1205 }
1206 
1207 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
1208  * and stderr if they are redirected. */
1209 static int setup_redirects(struct child_prog *prog, int squirrel[])
1210 {
1211 	int openfd, mode;
1212 	struct redir_struct *redir;
1213 
1214 	for (redir=prog->redirects; redir; redir=redir->next) {
1215 		if (redir->dup == -1 && redir->word.gl_pathv == NULL) {
1216 			/* something went wrong in the parse.  Pretend it didn't happen */
1217 			continue;
1218 		}
1219 		if (redir->dup == -1) {
1220 			mode=redir_table[redir->type].mode;
1221 			openfd = open(redir->word.gl_pathv[0], mode, 0666);
1222 			if (openfd < 0) {
1223 			/* this could get lost if stderr has been redirected, but
1224 			   bash and ash both lose it as well (though zsh doesn't!) */
1225 				perror_msg("error opening %s", redir->word.gl_pathv[0]);
1226 				return 1;
1227 			}
1228 		} else {
1229 			openfd = redir->dup;
1230 		}
1231 
1232 		if (openfd != redir->fd) {
1233 			if (squirrel && redir->fd < 3) {
1234 				squirrel[redir->fd] = dup(redir->fd);
1235 			}
1236 			if (openfd == -3) {
1237 				close(openfd);
1238 			} else {
1239 				dup2(openfd, redir->fd);
1240 				if (redir->dup == -1)
1241 					close (openfd);
1242 			}
1243 		}
1244 	}
1245 	return 0;
1246 }
1247 
1248 static void restore_redirects(int squirrel[])
1249 {
1250 	int i, fd;
1251 	for (i=0; i<3; i++) {
1252 		fd = squirrel[i];
1253 		if (fd != -1) {
1254 			/* No error checking.  I sure wouldn't know what
1255 			 * to do with an error if I found one! */
1256 			dup2(fd, i);
1257 			close(fd);
1258 		}
1259 	}
1260 }
1261 
1262 /* never returns */
1263 /* XXX no exit() here.  If you don't exec, use _exit instead.
1264  * The at_exit handlers apparently confuse the calling process,
1265  * in particular stdin handling.  Not sure why? */
1266 static void pseudo_exec(struct child_prog *child)
1267 {
1268 	int i, rcode;
1269 	char *p;
1270 	struct built_in_command *x;
1271 	if (child->argv) {
1272 		for (i=0; is_assignment(child->argv[i]); i++) {
1273 			debug_printf("pid %d environment modification: %s\n",getpid(),child->argv[i]);
1274 			p = insert_var_value(child->argv[i]);
1275 			putenv(strdup(p));
1276 			if (p != child->argv[i]) free(p);
1277 		}
1278 		child->argv+=i;  /* XXX this hack isn't so horrible, since we are about
1279 					to exit, and therefore don't need to keep data
1280 					structures consistent for free() use. */
1281 		/* If a variable is assigned in a forest, and nobody listens,
1282 		 * was it ever really set?
1283 		 */
1284 		if (child->argv[0] == NULL) {
1285 			_exit(EXIT_SUCCESS);
1286 		}
1287 
1288 		/*
1289 		 * Check if the command matches any of the builtins.
1290 		 * Depending on context, this might be redundant.  But it's
1291 		 * easier to waste a few CPU cycles than it is to figure out
1292 		 * if this is one of those cases.
1293 		 */
1294 		for (x = bltins; x->cmd; x++) {
1295 			if (strcmp(child->argv[0], x->cmd) == 0 ) {
1296 				debug_printf("builtin exec %s\n", child->argv[0]);
1297 				rcode = x->function(child);
1298 				fflush(stdout);
1299 				_exit(rcode);
1300 			}
1301 		}
1302 
1303 		/* Check if the command matches any busybox internal commands
1304 		 * ("applets") here.
1305 		 * FIXME: This feature is not 100% safe, since
1306 		 * BusyBox is not fully reentrant, so we have no guarantee the things
1307 		 * from the .bss are still zeroed, or that things from .data are still
1308 		 * at their defaults.  We could exec ourself from /proc/self/exe, but I
1309 		 * really dislike relying on /proc for things.  We could exec ourself
1310 		 * from global_argv[0], but if we are in a chroot, we may not be able
1311 		 * to find ourself... */
1312 #ifdef CONFIG_FEATURE_SH_STANDALONE_SHELL
1313 		{
1314 			int argc_l;
1315 			char** argv_l=child->argv;
1316 			char *name = child->argv[0];
1317 
1318 #ifdef CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN
1319 			/* Following discussions from November 2000 on the busybox mailing
1320 			 * list, the default configuration, (without
1321 			 * get_last_path_component()) lets the user force use of an
1322 			 * external command by specifying the full (with slashes) filename.
1323 			 * If you enable CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN then applets
1324 			 * _aways_ override external commands, so if you want to run
1325 			 * /bin/cat, it will use BusyBox cat even if /bin/cat exists on the
1326 			 * filesystem and is _not_ busybox.  Some systems may want this,
1327 			 * most do not.  */
1328 			name = get_last_path_component(name);
1329 #endif
1330 			/* Count argc for use in a second... */
1331 			for(argc_l=0;*argv_l!=NULL; argv_l++, argc_l++);
1332 			optind = 1;
1333 			debug_printf("running applet %s\n", name);
1334 			run_applet_by_name(name, argc_l, child->argv);
1335 		}
1336 #endif
1337 		debug_printf("exec of %s\n",child->argv[0]);
1338 		execvp(child->argv[0],child->argv);
1339 		perror_msg("couldn't exec: %s",child->argv[0]);
1340 		_exit(1);
1341 	} else if (child->group) {
1342 		debug_printf("runtime nesting to group\n");
1343 		interactive=0;    /* crucial!!!! */
1344 		rcode = run_list_real(child->group);
1345 		/* OK to leak memory by not calling free_pipe_list,
1346 		 * since this process is about to exit */
1347 		_exit(rcode);
1348 	} else {
1349 		/* Can happen.  See what bash does with ">foo" by itself. */
1350 		debug_printf("trying to pseudo_exec null command\n");
1351 		_exit(EXIT_SUCCESS);
1352 	}
1353 }
1354 
1355 static void insert_bg_job(struct pipe *pi)
1356 {
1357 	struct pipe *thejob;
1358 
1359 	/* Linear search for the ID of the job to use */
1360 	pi->jobid = 1;
1361 	for (thejob = job_list; thejob; thejob = thejob->next)
1362 		if (thejob->jobid >= pi->jobid)
1363 			pi->jobid = thejob->jobid + 1;
1364 
1365 	/* add thejob to the list of running jobs */
1366 	if (!job_list) {
1367 		thejob = job_list = xmalloc(sizeof(*thejob));
1368 	} else {
1369 		for (thejob = job_list; thejob->next; thejob = thejob->next) /* nothing */;
1370 		thejob->next = xmalloc(sizeof(*thejob));
1371 		thejob = thejob->next;
1372 	}
1373 
1374 	/* physically copy the struct job */
1375 	memcpy(thejob, pi, sizeof(struct pipe));
1376 	thejob->next = NULL;
1377 	thejob->running_progs = thejob->num_progs;
1378 	thejob->stopped_progs = 0;
1379 	thejob->text = xmalloc(BUFSIZ); /* cmdedit buffer size */
1380 
1381 	/*if (pi->progs[0] && pi->progs[0].argv && pi->progs[0].argv[0]) */
1382 	{
1383 		char *bar=thejob->text;
1384 		char **foo=pi->progs[0].argv;
1385 		while(foo && *foo) {
1386 			bar += sprintf(bar, "%s ", *foo++);
1387 		}
1388 	}
1389 
1390 	/* we don't wait for background thejobs to return -- append it
1391 	   to the list of backgrounded thejobs and leave it alone */
1392 	printf("[%d] %d\n", thejob->jobid, thejob->progs[0].pid);
1393 	last_bg_pid = thejob->progs[0].pid;
1394 	last_jobid = thejob->jobid;
1395 }
1396 
1397 /* remove a backgrounded job */
1398 static void remove_bg_job(struct pipe *pi)
1399 {
1400 	struct pipe *prev_pipe;
1401 
1402 	if (pi == job_list) {
1403 		job_list = pi->next;
1404 	} else {
1405 		prev_pipe = job_list;
1406 		while (prev_pipe->next != pi)
1407 			prev_pipe = prev_pipe->next;
1408 		prev_pipe->next = pi->next;
1409 	}
1410 	if (job_list)
1411 		last_jobid = job_list->jobid;
1412 	else
1413 		last_jobid = 0;
1414 
1415 	pi->stopped_progs = 0;
1416 	free_pipe(pi, 0);
1417 	free(pi);
1418 }
1419 
1420 /* Checks to see if any processes have exited -- if they
1421    have, figure out why and see if a job has completed */
1422 static int checkjobs(struct pipe* fg_pipe)
1423 {
1424 	int attributes;
1425 	int status;
1426 	int prognum = 0;
1427 	struct pipe *pi;
1428 	pid_t childpid;
1429 
1430 	attributes = WUNTRACED;
1431 	if (fg_pipe==NULL) {
1432 		attributes |= WNOHANG;
1433 	}
1434 
1435 	while ((childpid = waitpid(-1, &status, attributes)) > 0) {
1436 		if (fg_pipe) {
1437 			int i, rcode = 0;
1438 			for (i=0; i < fg_pipe->num_progs; i++) {
1439 				if (fg_pipe->progs[i].pid == childpid) {
1440 					if (i==fg_pipe->num_progs-1)
1441 						rcode=WEXITSTATUS(status);
1442 					(fg_pipe->num_progs)--;
1443 					return(rcode);
1444 				}
1445 			}
1446 		}
1447 
1448 		for (pi = job_list; pi; pi = pi->next) {
1449 			prognum = 0;
1450 			while (prognum < pi->num_progs && pi->progs[prognum].pid != childpid) {
1451 				prognum++;
1452 			}
1453 			if (prognum < pi->num_progs)
1454 				break;
1455 		}
1456 
1457 		if(pi==NULL) {
1458 			debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
1459 			continue;
1460 		}
1461 
1462 		if (WIFEXITED(status) || WIFSIGNALED(status)) {
1463 			/* child exited */
1464 			pi->running_progs--;
1465 			pi->progs[prognum].pid = 0;
1466 
1467 			if (!pi->running_progs) {
1468 				printf(JOB_STATUS_FORMAT, pi->jobid, "Done", pi->text);
1469 				remove_bg_job(pi);
1470 			}
1471 		} else {
1472 			/* child stopped */
1473 			pi->stopped_progs++;
1474 			pi->progs[prognum].is_stopped = 1;
1475 
1476 #if 0
1477 			/* Printing this stuff is a pain, since it tends to
1478 			 * overwrite the prompt an inconveinient moments.  So
1479 			 * don't do that.  */
1480 			if (pi->stopped_progs == pi->num_progs) {
1481 				printf("\n"JOB_STATUS_FORMAT, pi->jobid, "Stopped", pi->text);
1482 			}
1483 #endif
1484 		}
1485 	}
1486 
1487 	if (childpid == -1 && errno != ECHILD)
1488 		perror_msg("waitpid");
1489 
1490 	/* move the shell to the foreground */
1491 	/*if (interactive && tcsetpgrp(shell_terminal, getpgid(0))) */
1492 	/*	perror_msg("tcsetpgrp-2"); */
1493 	return -1;
1494 }
1495 
1496 /* Figure out our controlling tty, checking in order stderr,
1497  * stdin, and stdout.  If check_pgrp is set, also check that
1498  * we belong to the foreground process group associated with
1499  * that tty.  The value of shell_terminal is needed in order to call
1500  * tcsetpgrp(shell_terminal, ...); */
1501 void controlling_tty(int check_pgrp)
1502 {
1503 	pid_t curpgrp;
1504 
1505 	if ((curpgrp = tcgetpgrp(shell_terminal = 2)) < 0
1506 			&& (curpgrp = tcgetpgrp(shell_terminal = 0)) < 0
1507 			&& (curpgrp = tcgetpgrp(shell_terminal = 1)) < 0)
1508 		goto shell_terminal_error;
1509 
1510 	if (check_pgrp && curpgrp != getpgid(0))
1511 		goto shell_terminal_error;
1512 
1513 	return;
1514 
1515 shell_terminal_error:
1516 		shell_terminal = -1;
1517 		return;
1518 }
1519 #endif
1520 
1521 /* run_pipe_real() starts all the jobs, but doesn't wait for anything
1522  * to finish.  See checkjobs().
1523  *
1524  * return code is normally -1, when the caller has to wait for children
1525  * to finish to determine the exit status of the pipe.  If the pipe
1526  * is a simple builtin command, however, the action is done by the
1527  * time run_pipe_real returns, and the exit code is provided as the
1528  * return value.
1529  *
1530  * The input of the pipe is always stdin, the output is always
1531  * stdout.  The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
1532  * because it tries to avoid running the command substitution in
1533  * subshell, when that is in fact necessary.  The subshell process
1534  * now has its stdout directed to the input of the appropriate pipe,
1535  * so this routine is noticeably simpler.
1536  */
1537 static int run_pipe_real(struct pipe *pi)
1538 {
1539 	int i;
1540 #ifndef __U_BOOT__
1541 	int nextin, nextout;
1542 	int pipefds[2];				/* pipefds[0] is for reading */
1543 	struct child_prog *child;
1544 	struct built_in_command *x;
1545 	char *p;
1546 # if __GNUC__
1547 	/* Avoid longjmp clobbering */
1548 	(void) &i;
1549 	(void) &nextin;
1550 	(void) &nextout;
1551 	(void) &child;
1552 # endif
1553 #else
1554 	int nextin;
1555 	int flag = do_repeat ? CMD_FLAG_REPEAT : 0;
1556 	struct child_prog *child;
1557 	char *p;
1558 # if __GNUC__
1559 	/* Avoid longjmp clobbering */
1560 	(void) &i;
1561 	(void) &nextin;
1562 	(void) &child;
1563 # endif
1564 #endif	/* __U_BOOT__ */
1565 
1566 	nextin = 0;
1567 #ifndef __U_BOOT__
1568 	pi->pgrp = -1;
1569 #endif
1570 
1571 	/* Check if this is a simple builtin (not part of a pipe).
1572 	 * Builtins within pipes have to fork anyway, and are handled in
1573 	 * pseudo_exec.  "echo foo | read bar" doesn't work on bash, either.
1574 	 */
1575 	if (pi->num_progs == 1) child = & (pi->progs[0]);
1576 #ifndef __U_BOOT__
1577 	if (pi->num_progs == 1 && child->group && child->subshell == 0) {
1578 		int squirrel[] = {-1, -1, -1};
1579 		int rcode;
1580 		debug_printf("non-subshell grouping\n");
1581 		setup_redirects(child, squirrel);
1582 		/* XXX could we merge code with following builtin case,
1583 		 * by creating a pseudo builtin that calls run_list_real? */
1584 		rcode = run_list_real(child->group);
1585 		restore_redirects(squirrel);
1586 #else
1587 		if (pi->num_progs == 1 && child->group) {
1588 		int rcode;
1589 		debug_printf("non-subshell grouping\n");
1590 		rcode = run_list_real(child->group);
1591 #endif
1592 		return rcode;
1593 	} else if (pi->num_progs == 1 && pi->progs[0].argv != NULL) {
1594 		for (i=0; is_assignment(child->argv[i]); i++) { /* nothing */ }
1595 		if (i!=0 && child->argv[i]==NULL) {
1596 			/* assignments, but no command: set the local environment */
1597 			for (i=0; child->argv[i]!=NULL; i++) {
1598 
1599 				/* Ok, this case is tricky.  We have to decide if this is a
1600 				 * local variable, or an already exported variable.  If it is
1601 				 * already exported, we have to export the new value.  If it is
1602 				 * not exported, we need only set this as a local variable.
1603 				 * This junk is all to decide whether or not to export this
1604 				 * variable. */
1605 				int export_me=0;
1606 				char *name, *value;
1607 				name = xstrdup(child->argv[i]);
1608 				debug_printf("Local environment set: %s\n", name);
1609 				value = strchr(name, '=');
1610 				if (value)
1611 					*value=0;
1612 #ifndef __U_BOOT__
1613 				if ( get_local_var(name)) {
1614 					export_me=1;
1615 				}
1616 #endif
1617 				free(name);
1618 				p = insert_var_value(child->argv[i]);
1619 				set_local_var(p, export_me);
1620 				if (p != child->argv[i]) free(p);
1621 			}
1622 			return EXIT_SUCCESS;   /* don't worry about errors in set_local_var() yet */
1623 		}
1624 		for (i = 0; is_assignment(child->argv[i]); i++) {
1625 			p = insert_var_value(child->argv[i]);
1626 #ifndef __U_BOOT__
1627 			putenv(strdup(p));
1628 #else
1629 			set_local_var(p, 0);
1630 #endif
1631 			if (p != child->argv[i]) {
1632 				child->sp--;
1633 				free(p);
1634 			}
1635 		}
1636 		if (child->sp) {
1637 			char * str = NULL;
1638 
1639 			str = make_string(child->argv + i,
1640 					  child->argv_nonnull + i);
1641 			parse_string_outer(str, FLAG_EXIT_FROM_LOOP | FLAG_REPARSING);
1642 			free(str);
1643 			return last_return_code;
1644 		}
1645 #ifndef __U_BOOT__
1646 		for (x = bltins; x->cmd; x++) {
1647 			if (strcmp(child->argv[i], x->cmd) == 0 ) {
1648 				int squirrel[] = {-1, -1, -1};
1649 				int rcode;
1650 				if (x->function == builtin_exec && child->argv[i+1]==NULL) {
1651 					debug_printf("magic exec\n");
1652 					setup_redirects(child,NULL);
1653 					return EXIT_SUCCESS;
1654 				}
1655 				debug_printf("builtin inline %s\n", child->argv[0]);
1656 				/* XXX setup_redirects acts on file descriptors, not FILEs.
1657 				 * This is perfect for work that comes after exec().
1658 				 * Is it really safe for inline use?  Experimentally,
1659 				 * things seem to work with glibc. */
1660 				setup_redirects(child, squirrel);
1661 
1662 				child->argv += i;  /* XXX horrible hack */
1663 				rcode = x->function(child);
1664 				/* XXX restore hack so free() can work right */
1665 				child->argv -= i;
1666 				restore_redirects(squirrel);
1667 			}
1668 			return rcode;
1669 		}
1670 #else
1671 		/* check ";", because ,example , argv consist from
1672 		 * "help;flinfo" must not execute
1673 		 */
1674 		if (strchr(child->argv[i], ';')) {
1675 			printf("Unknown command '%s' - try 'help' or use "
1676 					"'run' command\n", child->argv[i]);
1677 			return -1;
1678 		}
1679 		/* Process the command */
1680 		return cmd_process(flag, child->argc, child->argv,
1681 				   &flag_repeat, NULL);
1682 #endif
1683 	}
1684 #ifndef __U_BOOT__
1685 
1686 	for (i = 0; i < pi->num_progs; i++) {
1687 		child = & (pi->progs[i]);
1688 
1689 		/* pipes are inserted between pairs of commands */
1690 		if ((i + 1) < pi->num_progs) {
1691 			if (pipe(pipefds)<0) perror_msg_and_die("pipe");
1692 			nextout = pipefds[1];
1693 		} else {
1694 			nextout=1;
1695 			pipefds[0] = -1;
1696 		}
1697 
1698 		/* XXX test for failed fork()? */
1699 		if (!(child->pid = fork())) {
1700 			/* Set the handling for job control signals back to the default.  */
1701 			signal(SIGINT, SIG_DFL);
1702 			signal(SIGQUIT, SIG_DFL);
1703 			signal(SIGTERM, SIG_DFL);
1704 			signal(SIGTSTP, SIG_DFL);
1705 			signal(SIGTTIN, SIG_DFL);
1706 			signal(SIGTTOU, SIG_DFL);
1707 			signal(SIGCHLD, SIG_DFL);
1708 
1709 			close_all();
1710 
1711 			if (nextin != 0) {
1712 				dup2(nextin, 0);
1713 				close(nextin);
1714 			}
1715 			if (nextout != 1) {
1716 				dup2(nextout, 1);
1717 				close(nextout);
1718 			}
1719 			if (pipefds[0]!=-1) {
1720 				close(pipefds[0]);  /* opposite end of our output pipe */
1721 			}
1722 
1723 			/* Like bash, explicit redirects override pipes,
1724 			 * and the pipe fd is available for dup'ing. */
1725 			setup_redirects(child,NULL);
1726 
1727 			if (interactive && pi->followup!=PIPE_BG) {
1728 				/* If we (the child) win the race, put ourselves in the process
1729 				 * group whose leader is the first process in this pipe. */
1730 				if (pi->pgrp < 0) {
1731 					pi->pgrp = getpid();
1732 				}
1733 				if (setpgid(0, pi->pgrp) == 0) {
1734 					tcsetpgrp(2, pi->pgrp);
1735 				}
1736 			}
1737 
1738 			pseudo_exec(child);
1739 		}
1740 
1741 
1742 		/* put our child in the process group whose leader is the
1743 		   first process in this pipe */
1744 		if (pi->pgrp < 0) {
1745 			pi->pgrp = child->pid;
1746 		}
1747 		/* Don't check for errors.  The child may be dead already,
1748 		 * in which case setpgid returns error code EACCES. */
1749 		setpgid(child->pid, pi->pgrp);
1750 
1751 		if (nextin != 0)
1752 			close(nextin);
1753 		if (nextout != 1)
1754 			close(nextout);
1755 
1756 		/* If there isn't another process, nextin is garbage
1757 		   but it doesn't matter */
1758 		nextin = pipefds[0];
1759 	}
1760 #endif
1761 	return -1;
1762 }
1763 
1764 static int run_list_real(struct pipe *pi)
1765 {
1766 	char *save_name = NULL;
1767 	char **list = NULL;
1768 	char **save_list = NULL;
1769 	struct pipe *rpipe;
1770 	int flag_rep = 0;
1771 #ifndef __U_BOOT__
1772 	int save_num_progs;
1773 #endif
1774 	int rcode=0, flag_skip=1;
1775 	int flag_restore = 0;
1776 	int if_code=0, next_if_code=0;  /* need double-buffer to handle elif */
1777 	reserved_style rmode, skip_more_in_this_rmode=RES_XXXX;
1778 	/* check syntax for "for" */
1779 	for (rpipe = pi; rpipe; rpipe = rpipe->next) {
1780 		if ((rpipe->r_mode == RES_IN ||
1781 		    rpipe->r_mode == RES_FOR) &&
1782 		    (rpipe->next == NULL)) {
1783 				syntax();
1784 #ifdef __U_BOOT__
1785 				flag_repeat = 0;
1786 #endif
1787 				return 1;
1788 		}
1789 		if ((rpipe->r_mode == RES_IN &&
1790 			(rpipe->next->r_mode == RES_IN &&
1791 			rpipe->next->progs->argv != NULL))||
1792 			(rpipe->r_mode == RES_FOR &&
1793 			rpipe->next->r_mode != RES_IN)) {
1794 				syntax();
1795 #ifdef __U_BOOT__
1796 				flag_repeat = 0;
1797 #endif
1798 				return 1;
1799 		}
1800 	}
1801 	for (; pi; pi = (flag_restore != 0) ? rpipe : pi->next) {
1802 		if (pi->r_mode == RES_WHILE || pi->r_mode == RES_UNTIL ||
1803 			pi->r_mode == RES_FOR) {
1804 #ifdef __U_BOOT__
1805 				/* check Ctrl-C */
1806 				ctrlc();
1807 				if ((had_ctrlc())) {
1808 					return 1;
1809 				}
1810 #endif
1811 				flag_restore = 0;
1812 				if (!rpipe) {
1813 					flag_rep = 0;
1814 					rpipe = pi;
1815 				}
1816 		}
1817 		rmode = pi->r_mode;
1818 		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);
1819 		if (rmode == skip_more_in_this_rmode && flag_skip) {
1820 			if (pi->followup == PIPE_SEQ) flag_skip=0;
1821 			continue;
1822 		}
1823 		flag_skip = 1;
1824 		skip_more_in_this_rmode = RES_XXXX;
1825 		if (rmode == RES_THEN || rmode == RES_ELSE) if_code = next_if_code;
1826 		if (rmode == RES_THEN &&  if_code) continue;
1827 		if (rmode == RES_ELSE && !if_code) continue;
1828 		if (rmode == RES_ELIF && !if_code) break;
1829 		if (rmode == RES_FOR && pi->num_progs) {
1830 			if (!list) {
1831 				/* if no variable values after "in" we skip "for" */
1832 				if (!pi->next->progs->argv) continue;
1833 				/* create list of variable values */
1834 				list = make_list_in(pi->next->progs->argv,
1835 					pi->progs->argv[0]);
1836 				save_list = list;
1837 				save_name = pi->progs->argv[0];
1838 				pi->progs->argv[0] = NULL;
1839 				flag_rep = 1;
1840 			}
1841 			if (!(*list)) {
1842 				free(pi->progs->argv[0]);
1843 				free(save_list);
1844 				list = NULL;
1845 				flag_rep = 0;
1846 				pi->progs->argv[0] = save_name;
1847 #ifndef __U_BOOT__
1848 				pi->progs->glob_result.gl_pathv[0] =
1849 					pi->progs->argv[0];
1850 #endif
1851 				continue;
1852 			} else {
1853 				/* insert new value from list for variable */
1854 				if (pi->progs->argv[0])
1855 					free(pi->progs->argv[0]);
1856 				pi->progs->argv[0] = *list++;
1857 #ifndef __U_BOOT__
1858 				pi->progs->glob_result.gl_pathv[0] =
1859 					pi->progs->argv[0];
1860 #endif
1861 			}
1862 		}
1863 		if (rmode == RES_IN) continue;
1864 		if (rmode == RES_DO) {
1865 			if (!flag_rep) continue;
1866 		}
1867 		if (rmode == RES_DONE) {
1868 			if (flag_rep) {
1869 				flag_restore = 1;
1870 			} else {
1871 				rpipe = NULL;
1872 			}
1873 		}
1874 		if (pi->num_progs == 0) continue;
1875 #ifndef __U_BOOT__
1876 		save_num_progs = pi->num_progs; /* save number of programs */
1877 #endif
1878 		rcode = run_pipe_real(pi);
1879 		debug_printf("run_pipe_real returned %d\n",rcode);
1880 #ifndef __U_BOOT__
1881 		if (rcode!=-1) {
1882 			/* We only ran a builtin: rcode was set by the return value
1883 			 * of run_pipe_real(), and we don't need to wait for anything. */
1884 		} else if (pi->followup==PIPE_BG) {
1885 			/* XXX check bash's behavior with nontrivial pipes */
1886 			/* XXX compute jobid */
1887 			/* XXX what does bash do with attempts to background builtins? */
1888 			insert_bg_job(pi);
1889 			rcode = EXIT_SUCCESS;
1890 		} else {
1891 			if (interactive) {
1892 				/* move the new process group into the foreground */
1893 				if (tcsetpgrp(shell_terminal, pi->pgrp) && errno != ENOTTY)
1894 					perror_msg("tcsetpgrp-3");
1895 				rcode = checkjobs(pi);
1896 				/* move the shell to the foreground */
1897 				if (tcsetpgrp(shell_terminal, getpgid(0)) && errno != ENOTTY)
1898 					perror_msg("tcsetpgrp-4");
1899 			} else {
1900 				rcode = checkjobs(pi);
1901 			}
1902 			debug_printf("checkjobs returned %d\n",rcode);
1903 		}
1904 		last_return_code=rcode;
1905 #else
1906 		if (rcode < -1) {
1907 			last_return_code = -rcode - 2;
1908 			return -2;	/* exit */
1909 		}
1910 		last_return_code=(rcode == 0) ? 0 : 1;
1911 #endif
1912 #ifndef __U_BOOT__
1913 		pi->num_progs = save_num_progs; /* restore number of programs */
1914 #endif
1915 		if ( rmode == RES_IF || rmode == RES_ELIF )
1916 			next_if_code=rcode;  /* can be overwritten a number of times */
1917 		if (rmode == RES_WHILE)
1918 			flag_rep = !last_return_code;
1919 		if (rmode == RES_UNTIL)
1920 			flag_rep = last_return_code;
1921 		if ( (rcode==EXIT_SUCCESS && pi->followup==PIPE_OR) ||
1922 		     (rcode!=EXIT_SUCCESS && pi->followup==PIPE_AND) )
1923 			skip_more_in_this_rmode=rmode;
1924 #ifndef __U_BOOT__
1925 		checkjobs(NULL);
1926 #endif
1927 	}
1928 	return rcode;
1929 }
1930 
1931 /* broken, of course, but OK for testing */
1932 static char *indenter(int i)
1933 {
1934 	static char blanks[]="                                    ";
1935 	return &blanks[sizeof(blanks)-i-1];
1936 }
1937 
1938 /* return code is the exit status of the pipe */
1939 static int free_pipe(struct pipe *pi, int indent)
1940 {
1941 	char **p;
1942 	struct child_prog *child;
1943 #ifndef __U_BOOT__
1944 	struct redir_struct *r, *rnext;
1945 #endif
1946 	int a, i, ret_code=0;
1947 	char *ind = indenter(indent);
1948 
1949 #ifndef __U_BOOT__
1950 	if (pi->stopped_progs > 0)
1951 		return ret_code;
1952 	final_printf("%s run pipe: (pid %d)\n",ind,getpid());
1953 #endif
1954 	for (i=0; i<pi->num_progs; i++) {
1955 		child = &pi->progs[i];
1956 		final_printf("%s  command %d:\n",ind,i);
1957 		if (child->argv) {
1958 			for (a=0,p=child->argv; *p; a++,p++) {
1959 				final_printf("%s   argv[%d] = %s\n",ind,a,*p);
1960 			}
1961 #ifndef __U_BOOT__
1962 			globfree(&child->glob_result);
1963 #else
1964 			for (a = 0; a < child->argc; a++) {
1965 				free(child->argv[a]);
1966 			}
1967 			free(child->argv);
1968 			free(child->argv_nonnull);
1969 			child->argc = 0;
1970 #endif
1971 			child->argv=NULL;
1972 		} else if (child->group) {
1973 #ifndef __U_BOOT__
1974 			final_printf("%s   begin group (subshell:%d)\n",ind, child->subshell);
1975 #endif
1976 			ret_code = free_pipe_list(child->group,indent+3);
1977 			final_printf("%s   end group\n",ind);
1978 		} else {
1979 			final_printf("%s   (nil)\n",ind);
1980 		}
1981 #ifndef __U_BOOT__
1982 		for (r=child->redirects; r; r=rnext) {
1983 			final_printf("%s   redirect %d%s", ind, r->fd, redir_table[r->type].descrip);
1984 			if (r->dup == -1) {
1985 				/* guard against the case >$FOO, where foo is unset or blank */
1986 				if (r->word.gl_pathv) {
1987 					final_printf(" %s\n", *r->word.gl_pathv);
1988 					globfree(&r->word);
1989 				}
1990 			} else {
1991 				final_printf("&%d\n", r->dup);
1992 			}
1993 			rnext=r->next;
1994 			free(r);
1995 		}
1996 		child->redirects=NULL;
1997 #endif
1998 	}
1999 	free(pi->progs);   /* children are an array, they get freed all at once */
2000 	pi->progs=NULL;
2001 	return ret_code;
2002 }
2003 
2004 static int free_pipe_list(struct pipe *head, int indent)
2005 {
2006 	int rcode=0;   /* if list has no members */
2007 	struct pipe *pi, *next;
2008 	char *ind = indenter(indent);
2009 	for (pi=head; pi; pi=next) {
2010 		final_printf("%s pipe reserved mode %d\n", ind, pi->r_mode);
2011 		rcode = free_pipe(pi, indent);
2012 		final_printf("%s pipe followup code %d\n", ind, pi->followup);
2013 		next=pi->next;
2014 		pi->next=NULL;
2015 		free(pi);
2016 	}
2017 	return rcode;
2018 }
2019 
2020 /* Select which version we will use */
2021 static int run_list(struct pipe *pi)
2022 {
2023 	int rcode=0;
2024 #ifndef __U_BOOT__
2025 	if (fake_mode==0) {
2026 #endif
2027 		rcode = run_list_real(pi);
2028 #ifndef __U_BOOT__
2029 	}
2030 #endif
2031 	/* free_pipe_list has the side effect of clearing memory
2032 	 * In the long run that function can be merged with run_list_real,
2033 	 * but doing that now would hobble the debugging effort. */
2034 	free_pipe_list(pi,0);
2035 	return rcode;
2036 }
2037 
2038 /* The API for glob is arguably broken.  This routine pushes a non-matching
2039  * string into the output structure, removing non-backslashed backslashes.
2040  * If someone can prove me wrong, by performing this function within the
2041  * original glob(3) api, feel free to rewrite this routine into oblivion.
2042  * Return code (0 vs. GLOB_NOSPACE) matches glob(3).
2043  * XXX broken if the last character is '\\', check that before calling.
2044  */
2045 #ifndef __U_BOOT__
2046 static int globhack(const char *src, int flags, glob_t *pglob)
2047 {
2048 	int cnt=0, pathc;
2049 	const char *s;
2050 	char *dest;
2051 	for (cnt=1, s=src; s && *s; s++) {
2052 		if (*s == '\\') s++;
2053 		cnt++;
2054 	}
2055 	dest = malloc(cnt);
2056 	if (!dest) return GLOB_NOSPACE;
2057 	if (!(flags & GLOB_APPEND)) {
2058 		pglob->gl_pathv=NULL;
2059 		pglob->gl_pathc=0;
2060 		pglob->gl_offs=0;
2061 		pglob->gl_offs=0;
2062 	}
2063 	pathc = ++pglob->gl_pathc;
2064 	pglob->gl_pathv = realloc(pglob->gl_pathv, (pathc+1)*sizeof(*pglob->gl_pathv));
2065 	if (pglob->gl_pathv == NULL) return GLOB_NOSPACE;
2066 	pglob->gl_pathv[pathc-1]=dest;
2067 	pglob->gl_pathv[pathc]=NULL;
2068 	for (s=src; s && *s; s++, dest++) {
2069 		if (*s == '\\') s++;
2070 		*dest = *s;
2071 	}
2072 	*dest='\0';
2073 	return 0;
2074 }
2075 
2076 /* XXX broken if the last character is '\\', check that before calling */
2077 static int glob_needed(const char *s)
2078 {
2079 	for (; *s; s++) {
2080 		if (*s == '\\') s++;
2081 		if (strchr("*[?",*s)) return 1;
2082 	}
2083 	return 0;
2084 }
2085 
2086 #if 0
2087 static void globprint(glob_t *pglob)
2088 {
2089 	int i;
2090 	debug_printf("glob_t at %p:\n", pglob);
2091 	debug_printf("  gl_pathc=%d  gl_pathv=%p  gl_offs=%d  gl_flags=%d\n",
2092 		pglob->gl_pathc, pglob->gl_pathv, pglob->gl_offs, pglob->gl_flags);
2093 	for (i=0; i<pglob->gl_pathc; i++)
2094 		debug_printf("pglob->gl_pathv[%d] = %p = %s\n", i,
2095 			pglob->gl_pathv[i], pglob->gl_pathv[i]);
2096 }
2097 #endif
2098 
2099 static int xglob(o_string *dest, int flags, glob_t *pglob)
2100 {
2101 	int gr;
2102 
2103 	/* short-circuit for null word */
2104 	/* we can code this better when the debug_printf's are gone */
2105 	if (dest->length == 0) {
2106 		if (dest->nonnull) {
2107 			/* bash man page calls this an "explicit" null */
2108 			gr = globhack(dest->data, flags, pglob);
2109 			debug_printf("globhack returned %d\n",gr);
2110 		} else {
2111 			return 0;
2112 		}
2113 	} else if (glob_needed(dest->data)) {
2114 		gr = glob(dest->data, flags, NULL, pglob);
2115 		debug_printf("glob returned %d\n",gr);
2116 		if (gr == GLOB_NOMATCH) {
2117 			/* quote removal, or more accurately, backslash removal */
2118 			gr = globhack(dest->data, flags, pglob);
2119 			debug_printf("globhack returned %d\n",gr);
2120 		}
2121 	} else {
2122 		gr = globhack(dest->data, flags, pglob);
2123 		debug_printf("globhack returned %d\n",gr);
2124 	}
2125 	if (gr == GLOB_NOSPACE)
2126 		error_msg_and_die("out of memory during glob");
2127 	if (gr != 0) { /* GLOB_ABORTED ? */
2128 		error_msg("glob(3) error %d",gr);
2129 	}
2130 	/* globprint(glob_target); */
2131 	return gr;
2132 }
2133 #endif
2134 
2135 #ifdef __U_BOOT__
2136 static char *get_dollar_var(char ch);
2137 #endif
2138 
2139 /* This is used to get/check local shell variables */
2140 char *get_local_var(const char *s)
2141 {
2142 	struct variables *cur;
2143 
2144 	if (!s)
2145 		return NULL;
2146 
2147 #ifdef __U_BOOT__
2148 	if (*s == '$')
2149 		return get_dollar_var(s[1]);
2150 #endif
2151 
2152 	for (cur = top_vars; cur; cur=cur->next)
2153 		if(strcmp(cur->name, s)==0)
2154 			return cur->value;
2155 	return NULL;
2156 }
2157 
2158 /* This is used to set local shell variables
2159    flg_export==0 if only local (not exporting) variable
2160    flg_export==1 if "new" exporting environ
2161    flg_export>1  if current startup environ (not call putenv()) */
2162 int set_local_var(const char *s, int flg_export)
2163 {
2164 	char *name, *value;
2165 	int result=0;
2166 	struct variables *cur;
2167 
2168 #ifdef __U_BOOT__
2169 	/* might be possible! */
2170 	if (!isalpha(*s))
2171 		return -1;
2172 #endif
2173 
2174 	name=strdup(s);
2175 
2176 #ifdef __U_BOOT__
2177 	if (env_get(name) != NULL) {
2178 		printf ("ERROR: "
2179 				"There is a global environment variable with the same name.\n");
2180 		free(name);
2181 		return -1;
2182 	}
2183 #endif
2184 	/* Assume when we enter this function that we are already in
2185 	 * NAME=VALUE format.  So the first order of business is to
2186 	 * split 's' on the '=' into 'name' and 'value' */
2187 	value = strchr(name, '=');
2188 	if (value == NULL || *(value + 1) == 0) {
2189 		free(name);
2190 		return -1;
2191 	}
2192 	*value++ = 0;
2193 
2194 	for(cur = top_vars; cur; cur = cur->next) {
2195 		if(strcmp(cur->name, name)==0)
2196 			break;
2197 	}
2198 
2199 	if(cur) {
2200 		if(strcmp(cur->value, value)==0) {
2201 			if(flg_export>0 && cur->flg_export==0)
2202 				cur->flg_export=flg_export;
2203 			else
2204 				result++;
2205 		} else {
2206 			if(cur->flg_read_only) {
2207 				error_msg("%s: readonly variable", name);
2208 				result = -1;
2209 			} else {
2210 				if(flg_export>0 || cur->flg_export>1)
2211 					cur->flg_export=1;
2212 				free(cur->value);
2213 
2214 				cur->value = strdup(value);
2215 			}
2216 		}
2217 	} else {
2218 		cur = malloc(sizeof(struct variables));
2219 		if(!cur) {
2220 			result = -1;
2221 		} else {
2222 			cur->name = strdup(name);
2223 			if (cur->name == NULL) {
2224 				free(cur);
2225 				result = -1;
2226 			} else {
2227 				struct variables *bottom = top_vars;
2228 				cur->value = strdup(value);
2229 				cur->next = NULL;
2230 				cur->flg_export = flg_export;
2231 				cur->flg_read_only = 0;
2232 				while(bottom->next) bottom=bottom->next;
2233 				bottom->next = cur;
2234 			}
2235 		}
2236 	}
2237 
2238 #ifndef __U_BOOT__
2239 	if(result==0 && cur->flg_export==1) {
2240 		*(value-1) = '=';
2241 		result = putenv(name);
2242 	} else {
2243 #endif
2244 		free(name);
2245 #ifndef __U_BOOT__
2246 		if(result>0)            /* equivalent to previous set */
2247 			result = 0;
2248 	}
2249 #endif
2250 	return result;
2251 }
2252 
2253 void unset_local_var(const char *name)
2254 {
2255 	struct variables *cur;
2256 
2257 	if (name) {
2258 		for (cur = top_vars; cur; cur=cur->next) {
2259 			if(strcmp(cur->name, name)==0)
2260 				break;
2261 		}
2262 		if (cur != NULL) {
2263 			struct variables *next = top_vars;
2264 			if(cur->flg_read_only) {
2265 				error_msg("%s: readonly variable", name);
2266 				return;
2267 			} else {
2268 #ifndef __U_BOOT__
2269 				if(cur->flg_export)
2270 					unenv_set(cur->name);
2271 #endif
2272 				free(cur->name);
2273 				free(cur->value);
2274 				while (next->next != cur)
2275 					next = next->next;
2276 				next->next = cur->next;
2277 			}
2278 			free(cur);
2279 		}
2280 	}
2281 }
2282 
2283 static int is_assignment(const char *s)
2284 {
2285 	if (s == NULL)
2286 		return 0;
2287 
2288 	if (!isalpha(*s)) return 0;
2289 	++s;
2290 	while(isalnum(*s) || *s=='_') ++s;
2291 	return *s=='=';
2292 }
2293 
2294 #ifndef __U_BOOT__
2295 /* the src parameter allows us to peek forward to a possible &n syntax
2296  * for file descriptor duplication, e.g., "2>&1".
2297  * Return code is 0 normally, 1 if a syntax error is detected in src.
2298  * Resource errors (in xmalloc) cause the process to exit */
2299 static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
2300 	struct in_str *input)
2301 {
2302 	struct child_prog *child=ctx->child;
2303 	struct redir_struct *redir = child->redirects;
2304 	struct redir_struct *last_redir=NULL;
2305 
2306 	/* Create a new redir_struct and drop it onto the end of the linked list */
2307 	while(redir) {
2308 		last_redir=redir;
2309 		redir=redir->next;
2310 	}
2311 	redir = xmalloc(sizeof(struct redir_struct));
2312 	redir->next=NULL;
2313 	redir->word.gl_pathv=NULL;
2314 	if (last_redir) {
2315 		last_redir->next=redir;
2316 	} else {
2317 		child->redirects=redir;
2318 	}
2319 
2320 	redir->type=style;
2321 	redir->fd= (fd==-1) ? redir_table[style].default_fd : fd ;
2322 
2323 	debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
2324 
2325 	/* Check for a '2>&1' type redirect */
2326 	redir->dup = redirect_dup_num(input);
2327 	if (redir->dup == -2) return 1;  /* syntax error */
2328 	if (redir->dup != -1) {
2329 		/* Erik had a check here that the file descriptor in question
2330 		 * is legit; I postpone that to "run time"
2331 		 * A "-" representation of "close me" shows up as a -3 here */
2332 		debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
2333 	} else {
2334 		/* We do _not_ try to open the file that src points to,
2335 		 * since we need to return and let src be expanded first.
2336 		 * Set ctx->pending_redirect, so we know what to do at the
2337 		 * end of the next parsed word.
2338 		 */
2339 		ctx->pending_redirect = redir;
2340 	}
2341 	return 0;
2342 }
2343 #endif
2344 
2345 static struct pipe *new_pipe(void)
2346 {
2347 	struct pipe *pi;
2348 	pi = xmalloc(sizeof(struct pipe));
2349 	pi->num_progs = 0;
2350 	pi->progs = NULL;
2351 	pi->next = NULL;
2352 	pi->followup = 0;  /* invalid */
2353 	pi->r_mode = RES_NONE;
2354 	return pi;
2355 }
2356 
2357 static void initialize_context(struct p_context *ctx)
2358 {
2359 	ctx->pipe=NULL;
2360 #ifndef __U_BOOT__
2361 	ctx->pending_redirect=NULL;
2362 #endif
2363 	ctx->child=NULL;
2364 	ctx->list_head=new_pipe();
2365 	ctx->pipe=ctx->list_head;
2366 	ctx->w=RES_NONE;
2367 	ctx->stack=NULL;
2368 #ifdef __U_BOOT__
2369 	ctx->old_flag=0;
2370 #endif
2371 	done_command(ctx);   /* creates the memory for working child */
2372 }
2373 
2374 /* normal return is 0
2375  * if a reserved word is found, and processed, return 1
2376  * should handle if, then, elif, else, fi, for, while, until, do, done.
2377  * case, function, and select are obnoxious, save those for later.
2378  */
2379 struct reserved_combo {
2380 	char *literal;
2381 	int code;
2382 	long flag;
2383 };
2384 /* Mostly a list of accepted follow-up reserved words.
2385  * FLAG_END means we are done with the sequence, and are ready
2386  * to turn the compound list into a command.
2387  * FLAG_START means the word must start a new compound list.
2388  */
2389 static struct reserved_combo reserved_list[] = {
2390 	{ "if",    RES_IF,    FLAG_THEN | FLAG_START },
2391 	{ "then",  RES_THEN,  FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2392 	{ "elif",  RES_ELIF,  FLAG_THEN },
2393 	{ "else",  RES_ELSE,  FLAG_FI   },
2394 	{ "fi",    RES_FI,    FLAG_END  },
2395 	{ "for",   RES_FOR,   FLAG_IN   | FLAG_START },
2396 	{ "while", RES_WHILE, FLAG_DO   | FLAG_START },
2397 	{ "until", RES_UNTIL, FLAG_DO   | FLAG_START },
2398 	{ "in",    RES_IN,    FLAG_DO   },
2399 	{ "do",    RES_DO,    FLAG_DONE },
2400 	{ "done",  RES_DONE,  FLAG_END  }
2401 };
2402 #define NRES (sizeof(reserved_list)/sizeof(struct reserved_combo))
2403 
2404 static int reserved_word(o_string *dest, struct p_context *ctx)
2405 {
2406 	struct reserved_combo *r;
2407 	for (r=reserved_list;
2408 		r<reserved_list+NRES; r++) {
2409 		if (strcmp(dest->data, r->literal) == 0) {
2410 			debug_printf("found reserved word %s, code %d\n",r->literal,r->code);
2411 			if (r->flag & FLAG_START) {
2412 				struct p_context *new = xmalloc(sizeof(struct p_context));
2413 				debug_printf("push stack\n");
2414 				if (ctx->w == RES_IN || ctx->w == RES_FOR) {
2415 					syntax();
2416 					free(new);
2417 					ctx->w = RES_SNTX;
2418 					b_reset(dest);
2419 					return 1;
2420 				}
2421 				*new = *ctx;   /* physical copy */
2422 				initialize_context(ctx);
2423 				ctx->stack=new;
2424 			} else if ( ctx->w == RES_NONE || ! (ctx->old_flag & (1<<r->code))) {
2425 				syntax();
2426 				ctx->w = RES_SNTX;
2427 				b_reset(dest);
2428 				return 1;
2429 			}
2430 			ctx->w=r->code;
2431 			ctx->old_flag = r->flag;
2432 			if (ctx->old_flag & FLAG_END) {
2433 				struct p_context *old;
2434 				debug_printf("pop stack\n");
2435 				done_pipe(ctx,PIPE_SEQ);
2436 				old = ctx->stack;
2437 				old->child->group = ctx->list_head;
2438 #ifndef __U_BOOT__
2439 				old->child->subshell = 0;
2440 #endif
2441 				*ctx = *old;   /* physical copy */
2442 				free(old);
2443 			}
2444 			b_reset (dest);
2445 			return 1;
2446 		}
2447 	}
2448 	return 0;
2449 }
2450 
2451 /* normal return is 0.
2452  * Syntax or xglob errors return 1. */
2453 static int done_word(o_string *dest, struct p_context *ctx)
2454 {
2455 	struct child_prog *child=ctx->child;
2456 #ifndef __U_BOOT__
2457 	glob_t *glob_target;
2458 	int gr, flags = 0;
2459 #else
2460 	char *str, *s;
2461 	int argc, cnt;
2462 #endif
2463 
2464 	debug_printf("done_word: %s %p\n", dest->data, child);
2465 	if (dest->length == 0 && !dest->nonnull) {
2466 		debug_printf("  true null, ignored\n");
2467 		return 0;
2468 	}
2469 #ifndef __U_BOOT__
2470 	if (ctx->pending_redirect) {
2471 		glob_target = &ctx->pending_redirect->word;
2472 	} else {
2473 #endif
2474 		if (child->group) {
2475 			syntax();
2476 			return 1;  /* syntax error, groups and arglists don't mix */
2477 		}
2478 		if (!child->argv && (ctx->type & FLAG_PARSE_SEMICOLON)) {
2479 			debug_printf("checking %s for reserved-ness\n",dest->data);
2480 			if (reserved_word(dest,ctx)) return ctx->w==RES_SNTX;
2481 		}
2482 #ifndef __U_BOOT__
2483 		glob_target = &child->glob_result;
2484 		if (child->argv) flags |= GLOB_APPEND;
2485 #else
2486 		for (cnt = 1, s = dest->data; s && *s; s++) {
2487 			if (*s == '\\') s++;
2488 			cnt++;
2489 		}
2490 		str = malloc(cnt);
2491 		if (!str) return 1;
2492 		if ( child->argv == NULL) {
2493 			child->argc=0;
2494 		}
2495 		argc = ++child->argc;
2496 		child->argv = realloc(child->argv, (argc+1)*sizeof(*child->argv));
2497 		if (child->argv == NULL) {
2498 			free(str);
2499 			return 1;
2500 		}
2501 		child->argv_nonnull = realloc(child->argv_nonnull,
2502 					(argc+1)*sizeof(*child->argv_nonnull));
2503 		if (child->argv_nonnull == NULL) {
2504 			free(str);
2505 			return 1;
2506 		}
2507 		child->argv[argc-1]=str;
2508 		child->argv_nonnull[argc-1] = dest->nonnull;
2509 		child->argv[argc]=NULL;
2510 		child->argv_nonnull[argc] = 0;
2511 		for (s = dest->data; s && *s; s++,str++) {
2512 			if (*s == '\\') s++;
2513 			*str = *s;
2514 		}
2515 		*str = '\0';
2516 #endif
2517 #ifndef __U_BOOT__
2518 	}
2519 	gr = xglob(dest, flags, glob_target);
2520 	if (gr != 0) return 1;
2521 #endif
2522 
2523 	b_reset(dest);
2524 #ifndef __U_BOOT__
2525 	if (ctx->pending_redirect) {
2526 		ctx->pending_redirect=NULL;
2527 		if (glob_target->gl_pathc != 1) {
2528 			error_msg("ambiguous redirect");
2529 			return 1;
2530 		}
2531 	} else {
2532 		child->argv = glob_target->gl_pathv;
2533 	}
2534 #endif
2535 	if (ctx->w == RES_FOR) {
2536 		done_word(dest,ctx);
2537 		done_pipe(ctx,PIPE_SEQ);
2538 	}
2539 	return 0;
2540 }
2541 
2542 /* The only possible error here is out of memory, in which case
2543  * xmalloc exits. */
2544 static int done_command(struct p_context *ctx)
2545 {
2546 	/* The child is really already in the pipe structure, so
2547 	 * advance the pipe counter and make a new, null child.
2548 	 * Only real trickiness here is that the uncommitted
2549 	 * child structure, to which ctx->child points, is not
2550 	 * counted in pi->num_progs. */
2551 	struct pipe *pi=ctx->pipe;
2552 	struct child_prog *prog=ctx->child;
2553 
2554 	if (prog && prog->group == NULL
2555 		 && prog->argv == NULL
2556 #ifndef __U_BOOT__
2557 		 && prog->redirects == NULL) {
2558 #else
2559 										) {
2560 #endif
2561 		debug_printf("done_command: skipping null command\n");
2562 		return 0;
2563 	} else if (prog) {
2564 		pi->num_progs++;
2565 		debug_printf("done_command: num_progs incremented to %d\n",pi->num_progs);
2566 	} else {
2567 		debug_printf("done_command: initializing\n");
2568 	}
2569 	pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
2570 
2571 	prog = pi->progs + pi->num_progs;
2572 #ifndef __U_BOOT__
2573 	prog->redirects = NULL;
2574 #endif
2575 	prog->argv = NULL;
2576 	prog->argv_nonnull = NULL;
2577 #ifndef __U_BOOT__
2578 	prog->is_stopped = 0;
2579 #endif
2580 	prog->group = NULL;
2581 #ifndef __U_BOOT__
2582 	prog->glob_result.gl_pathv = NULL;
2583 	prog->family = pi;
2584 #endif
2585 	prog->sp = 0;
2586 	ctx->child = prog;
2587 	prog->type = ctx->type;
2588 
2589 	/* but ctx->pipe and ctx->list_head remain unchanged */
2590 	return 0;
2591 }
2592 
2593 static int done_pipe(struct p_context *ctx, pipe_style type)
2594 {
2595 	struct pipe *new_p;
2596 	done_command(ctx);  /* implicit closure of previous command */
2597 	debug_printf("done_pipe, type %d\n", type);
2598 	ctx->pipe->followup = type;
2599 	ctx->pipe->r_mode = ctx->w;
2600 	new_p=new_pipe();
2601 	ctx->pipe->next = new_p;
2602 	ctx->pipe = new_p;
2603 	ctx->child = NULL;
2604 	done_command(ctx);  /* set up new pipe to accept commands */
2605 	return 0;
2606 }
2607 
2608 #ifndef __U_BOOT__
2609 /* peek ahead in the in_str to find out if we have a "&n" construct,
2610  * as in "2>&1", that represents duplicating a file descriptor.
2611  * returns either -2 (syntax error), -1 (no &), or the number found.
2612  */
2613 static int redirect_dup_num(struct in_str *input)
2614 {
2615 	int ch, d=0, ok=0;
2616 	ch = b_peek(input);
2617 	if (ch != '&') return -1;
2618 
2619 	b_getch(input);  /* get the & */
2620 	ch=b_peek(input);
2621 	if (ch == '-') {
2622 		b_getch(input);
2623 		return -3;  /* "-" represents "close me" */
2624 	}
2625 	while (isdigit(ch)) {
2626 		d = d*10+(ch-'0');
2627 		ok=1;
2628 		b_getch(input);
2629 		ch = b_peek(input);
2630 	}
2631 	if (ok) return d;
2632 
2633 	error_msg("ambiguous redirect");
2634 	return -2;
2635 }
2636 
2637 /* If a redirect is immediately preceded by a number, that number is
2638  * supposed to tell which file descriptor to redirect.  This routine
2639  * looks for such preceding numbers.  In an ideal world this routine
2640  * needs to handle all the following classes of redirects...
2641  *     echo 2>foo     # redirects fd  2 to file "foo", nothing passed to echo
2642  *     echo 49>foo    # redirects fd 49 to file "foo", nothing passed to echo
2643  *     echo -2>foo    # redirects fd  1 to file "foo",    "-2" passed to echo
2644  *     echo 49x>foo   # redirects fd  1 to file "foo",   "49x" passed to echo
2645  * A -1 output from this program means no valid number was found, so the
2646  * caller should use the appropriate default for this redirection.
2647  */
2648 static int redirect_opt_num(o_string *o)
2649 {
2650 	int num;
2651 
2652 	if (o->length==0) return -1;
2653 	for(num=0; num<o->length; num++) {
2654 		if (!isdigit(*(o->data+num))) {
2655 			return -1;
2656 		}
2657 	}
2658 	/* reuse num (and save an int) */
2659 	num=atoi(o->data);
2660 	b_reset(o);
2661 	return num;
2662 }
2663 
2664 FILE *generate_stream_from_list(struct pipe *head)
2665 {
2666 	FILE *pf;
2667 #if 1
2668 	int pid, channel[2];
2669 	if (pipe(channel)<0) perror_msg_and_die("pipe");
2670 	pid=fork();
2671 	if (pid<0) {
2672 		perror_msg_and_die("fork");
2673 	} else if (pid==0) {
2674 		close(channel[0]);
2675 		if (channel[1] != 1) {
2676 			dup2(channel[1],1);
2677 			close(channel[1]);
2678 		}
2679 #if 0
2680 #define SURROGATE "surrogate response"
2681 		write(1,SURROGATE,sizeof(SURROGATE));
2682 		_exit(run_list(head));
2683 #else
2684 		_exit(run_list_real(head));   /* leaks memory */
2685 #endif
2686 	}
2687 	debug_printf("forked child %d\n",pid);
2688 	close(channel[1]);
2689 	pf = fdopen(channel[0],"r");
2690 	debug_printf("pipe on FILE *%p\n",pf);
2691 #else
2692 	free_pipe_list(head,0);
2693 	pf=popen("echo surrogate response","r");
2694 	debug_printf("started fake pipe on FILE *%p\n",pf);
2695 #endif
2696 	return pf;
2697 }
2698 
2699 /* this version hacked for testing purposes */
2700 /* return code is exit status of the process that is run. */
2701 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end)
2702 {
2703 	int retcode;
2704 	o_string result=NULL_O_STRING;
2705 	struct p_context inner;
2706 	FILE *p;
2707 	struct in_str pipe_str;
2708 	initialize_context(&inner);
2709 
2710 	/* recursion to generate command */
2711 	retcode = parse_stream(&result, &inner, input, subst_end);
2712 	if (retcode != 0) return retcode;  /* syntax error or EOF */
2713 	done_word(&result, &inner);
2714 	done_pipe(&inner, PIPE_SEQ);
2715 	b_free(&result);
2716 
2717 	p=generate_stream_from_list(inner.list_head);
2718 	if (p==NULL) return 1;
2719 	mark_open(fileno(p));
2720 	setup_file_in_str(&pipe_str, p);
2721 
2722 	/* now send results of command back into original context */
2723 	retcode = parse_stream(dest, ctx, &pipe_str, '\0');
2724 	/* XXX In case of a syntax error, should we try to kill the child?
2725 	 * That would be tough to do right, so just read until EOF. */
2726 	if (retcode == 1) {
2727 		while (b_getch(&pipe_str)!=EOF) { /* discard */ };
2728 	}
2729 
2730 	debug_printf("done reading from pipe, pclose()ing\n");
2731 	/* This is the step that wait()s for the child.  Should be pretty
2732 	 * safe, since we just read an EOF from its stdout.  We could try
2733 	 * to better, by using wait(), and keeping track of background jobs
2734 	 * at the same time.  That would be a lot of work, and contrary
2735 	 * to the KISS philosophy of this program. */
2736 	mark_closed(fileno(p));
2737 	retcode=pclose(p);
2738 	free_pipe_list(inner.list_head,0);
2739 	debug_printf("pclosed, retcode=%d\n",retcode);
2740 	/* XXX this process fails to trim a single trailing newline */
2741 	return retcode;
2742 }
2743 
2744 static int parse_group(o_string *dest, struct p_context *ctx,
2745 	struct in_str *input, int ch)
2746 {
2747 	int rcode, endch=0;
2748 	struct p_context sub;
2749 	struct child_prog *child = ctx->child;
2750 	if (child->argv) {
2751 		syntax();
2752 		return 1;  /* syntax error, groups and arglists don't mix */
2753 	}
2754 	initialize_context(&sub);
2755 	switch(ch) {
2756 		case '(': endch=')'; child->subshell=1; break;
2757 		case '{': endch='}'; break;
2758 		default: syntax();   /* really logic error */
2759 	}
2760 	rcode=parse_stream(dest,&sub,input,endch);
2761 	done_word(dest,&sub); /* finish off the final word in the subcontext */
2762 	done_pipe(&sub, PIPE_SEQ);  /* and the final command there, too */
2763 	child->group = sub.list_head;
2764 	return rcode;
2765 	/* child remains "open", available for possible redirects */
2766 }
2767 #endif
2768 
2769 /* basically useful version until someone wants to get fancier,
2770  * see the bash man page under "Parameter Expansion" */
2771 static char *lookup_param(char *src)
2772 {
2773 	char *p;
2774 	char *sep;
2775 	char *default_val = NULL;
2776 	int assign = 0;
2777 	int expand_empty = 0;
2778 
2779 	if (!src)
2780 		return NULL;
2781 
2782 	sep = strchr(src, ':');
2783 
2784 	if (sep) {
2785 		*sep = '\0';
2786 		if (*(sep + 1) == '-')
2787 			default_val = sep+2;
2788 		if (*(sep + 1) == '=') {
2789 			default_val = sep+2;
2790 			assign = 1;
2791 		}
2792 		if (*(sep + 1) == '+') {
2793 			default_val = sep+2;
2794 			expand_empty = 1;
2795 		}
2796 	}
2797 
2798 	p = env_get(src);
2799 	if (!p)
2800 		p = get_local_var(src);
2801 
2802 	if (!p || strlen(p) == 0) {
2803 		p = default_val;
2804 		if (assign) {
2805 			char *var = malloc(strlen(src)+strlen(default_val)+2);
2806 			if (var) {
2807 				sprintf(var, "%s=%s", src, default_val);
2808 				set_local_var(var, 0);
2809 			}
2810 			free(var);
2811 		}
2812 	} else if (expand_empty) {
2813 		p += strlen(p);
2814 	}
2815 
2816 	if (sep)
2817 		*sep = ':';
2818 
2819 	return p;
2820 }
2821 
2822 #ifdef __U_BOOT__
2823 static char *get_dollar_var(char ch)
2824 {
2825 	static char buf[40];
2826 
2827 	buf[0] = '\0';
2828 	switch (ch) {
2829 		case '?':
2830 			sprintf(buf, "%u", (unsigned int)last_return_code);
2831 			break;
2832 		default:
2833 			return NULL;
2834 	}
2835 	return buf;
2836 }
2837 #endif
2838 
2839 /* return code: 0 for OK, 1 for syntax error */
2840 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input)
2841 {
2842 #ifndef __U_BOOT__
2843 	int i, advance=0;
2844 #else
2845 	int advance=0;
2846 #endif
2847 #ifndef __U_BOOT__
2848 	char sep[]=" ";
2849 #endif
2850 	int ch = input->peek(input);  /* first character after the $ */
2851 	debug_printf("handle_dollar: ch=%c\n",ch);
2852 	if (isalpha(ch)) {
2853 		b_addchr(dest, SPECIAL_VAR_SYMBOL);
2854 		ctx->child->sp++;
2855 		while(ch=b_peek(input),isalnum(ch) || ch=='_') {
2856 			b_getch(input);
2857 			b_addchr(dest,ch);
2858 		}
2859 		b_addchr(dest, SPECIAL_VAR_SYMBOL);
2860 #ifndef __U_BOOT__
2861 	} else if (isdigit(ch)) {
2862 		i = ch-'0';  /* XXX is $0 special? */
2863 		if (i<global_argc) {
2864 			parse_string(dest, ctx, global_argv[i]); /* recursion */
2865 		}
2866 		advance = 1;
2867 #endif
2868 	} else switch (ch) {
2869 #ifndef __U_BOOT__
2870 		case '$':
2871 			b_adduint(dest,getpid());
2872 			advance = 1;
2873 			break;
2874 		case '!':
2875 			if (last_bg_pid > 0) b_adduint(dest, last_bg_pid);
2876 			advance = 1;
2877 			break;
2878 #endif
2879 		case '?':
2880 #ifndef __U_BOOT__
2881 			b_adduint(dest,last_return_code);
2882 #else
2883 			ctx->child->sp++;
2884 			b_addchr(dest, SPECIAL_VAR_SYMBOL);
2885 			b_addchr(dest, '$');
2886 			b_addchr(dest, '?');
2887 			b_addchr(dest, SPECIAL_VAR_SYMBOL);
2888 #endif
2889 			advance = 1;
2890 			break;
2891 #ifndef __U_BOOT__
2892 		case '#':
2893 			b_adduint(dest,global_argc ? global_argc-1 : 0);
2894 			advance = 1;
2895 			break;
2896 #endif
2897 		case '{':
2898 			b_addchr(dest, SPECIAL_VAR_SYMBOL);
2899 			ctx->child->sp++;
2900 			b_getch(input);
2901 			/* XXX maybe someone will try to escape the '}' */
2902 			while(ch=b_getch(input),ch!=EOF && ch!='}') {
2903 				b_addchr(dest,ch);
2904 			}
2905 			if (ch != '}') {
2906 				syntax();
2907 				return 1;
2908 			}
2909 			b_addchr(dest, SPECIAL_VAR_SYMBOL);
2910 			break;
2911 #ifndef __U_BOOT__
2912 		case '(':
2913 			b_getch(input);
2914 			process_command_subs(dest, ctx, input, ')');
2915 			break;
2916 		case '*':
2917 			sep[0]=ifs[0];
2918 			for (i=1; i<global_argc; i++) {
2919 				parse_string(dest, ctx, global_argv[i]);
2920 				if (i+1 < global_argc) parse_string(dest, ctx, sep);
2921 			}
2922 			break;
2923 		case '@':
2924 		case '-':
2925 		case '_':
2926 			/* still unhandled, but should be eventually */
2927 			error_msg("unhandled syntax: $%c",ch);
2928 			return 1;
2929 			break;
2930 #endif
2931 		default:
2932 			b_addqchr(dest,'$',dest->quote);
2933 	}
2934 	/* Eat the character if the flag was set.  If the compiler
2935 	 * is smart enough, we could substitute "b_getch(input);"
2936 	 * for all the "advance = 1;" above, and also end up with
2937 	 * a nice size-optimized program.  Hah!  That'll be the day.
2938 	 */
2939 	if (advance) b_getch(input);
2940 	return 0;
2941 }
2942 
2943 #ifndef __U_BOOT__
2944 int parse_string(o_string *dest, struct p_context *ctx, const char *src)
2945 {
2946 	struct in_str foo;
2947 	setup_string_in_str(&foo, src);
2948 	return parse_stream(dest, ctx, &foo, '\0');
2949 }
2950 #endif
2951 
2952 /* return code is 0 for normal exit, 1 for syntax error */
2953 static int parse_stream(o_string *dest, struct p_context *ctx,
2954 			struct in_str *input, int end_trigger)
2955 {
2956 	unsigned int ch, m;
2957 #ifndef __U_BOOT__
2958 	int redir_fd;
2959 	redir_type redir_style;
2960 #endif
2961 	int next;
2962 
2963 	/* Only double-quote state is handled in the state variable dest->quote.
2964 	 * A single-quote triggers a bypass of the main loop until its mate is
2965 	 * found.  When recursing, quote state is passed in via dest->quote. */
2966 
2967 	debug_printf("parse_stream, end_trigger=%d\n",end_trigger);
2968 	while ((ch=b_getch(input))!=EOF) {
2969 		m = map[ch];
2970 #ifdef __U_BOOT__
2971 		if (input->__promptme == 0) return 1;
2972 #endif
2973 		next = (ch == '\n') ? 0 : b_peek(input);
2974 
2975 		debug_printf("parse_stream: ch=%c (%d) m=%d quote=%d - %c\n",
2976 			ch >= ' ' ? ch : '.', ch, m,
2977 			dest->quote, ctx->stack == NULL ? '*' : '.');
2978 
2979 		if (m==0 || ((m==1 || m==2) && dest->quote)) {
2980 			b_addqchr(dest, ch, dest->quote);
2981 		} else {
2982 			if (m==2) {  /* unquoted IFS */
2983 				if (done_word(dest, ctx)) {
2984 					return 1;
2985 				}
2986 				/* If we aren't performing a substitution, treat a newline as a
2987 				 * command separator.  */
2988 				if (end_trigger != '\0' && ch=='\n')
2989 					done_pipe(ctx,PIPE_SEQ);
2990 			}
2991 			if (ch == end_trigger && !dest->quote && ctx->w==RES_NONE) {
2992 				debug_printf("leaving parse_stream (triggered)\n");
2993 				return 0;
2994 			}
2995 #if 0
2996 			if (ch=='\n') {
2997 				/* Yahoo!  Time to run with it! */
2998 				done_pipe(ctx,PIPE_SEQ);
2999 				run_list(ctx->list_head);
3000 				initialize_context(ctx);
3001 			}
3002 #endif
3003 			if (m!=2) switch (ch) {
3004 		case '#':
3005 			if (dest->length == 0 && !dest->quote) {
3006 				while(ch=b_peek(input),ch!=EOF && ch!='\n') { b_getch(input); }
3007 			} else {
3008 				b_addqchr(dest, ch, dest->quote);
3009 			}
3010 			break;
3011 		case '\\':
3012 			if (next == EOF) {
3013 				syntax();
3014 				return 1;
3015 			}
3016 			b_addqchr(dest, '\\', dest->quote);
3017 			b_addqchr(dest, b_getch(input), dest->quote);
3018 			break;
3019 		case '$':
3020 			if (handle_dollar(dest, ctx, input)!=0) return 1;
3021 			break;
3022 		case '\'':
3023 			dest->nonnull = 1;
3024 			while(ch=b_getch(input),ch!=EOF && ch!='\'') {
3025 #ifdef __U_BOOT__
3026 				if(input->__promptme == 0) return 1;
3027 #endif
3028 				b_addchr(dest,ch);
3029 			}
3030 			if (ch==EOF) {
3031 				syntax();
3032 				return 1;
3033 			}
3034 			break;
3035 		case '"':
3036 			dest->nonnull = 1;
3037 			dest->quote = !dest->quote;
3038 			break;
3039 #ifndef __U_BOOT__
3040 		case '`':
3041 			process_command_subs(dest, ctx, input, '`');
3042 			break;
3043 		case '>':
3044 			redir_fd = redirect_opt_num(dest);
3045 			done_word(dest, ctx);
3046 			redir_style=REDIRECT_OVERWRITE;
3047 			if (next == '>') {
3048 				redir_style=REDIRECT_APPEND;
3049 				b_getch(input);
3050 			} else if (next == '(') {
3051 				syntax();   /* until we support >(list) Process Substitution */
3052 				return 1;
3053 			}
3054 			setup_redirect(ctx, redir_fd, redir_style, input);
3055 			break;
3056 		case '<':
3057 			redir_fd = redirect_opt_num(dest);
3058 			done_word(dest, ctx);
3059 			redir_style=REDIRECT_INPUT;
3060 			if (next == '<') {
3061 				redir_style=REDIRECT_HEREIS;
3062 				b_getch(input);
3063 			} else if (next == '>') {
3064 				redir_style=REDIRECT_IO;
3065 				b_getch(input);
3066 			} else if (next == '(') {
3067 				syntax();   /* until we support <(list) Process Substitution */
3068 				return 1;
3069 			}
3070 			setup_redirect(ctx, redir_fd, redir_style, input);
3071 			break;
3072 #endif
3073 		case ';':
3074 			done_word(dest, ctx);
3075 			done_pipe(ctx,PIPE_SEQ);
3076 			break;
3077 		case '&':
3078 			done_word(dest, ctx);
3079 			if (next=='&') {
3080 				b_getch(input);
3081 				done_pipe(ctx,PIPE_AND);
3082 			} else {
3083 #ifndef __U_BOOT__
3084 				done_pipe(ctx,PIPE_BG);
3085 #else
3086 				syntax_err();
3087 				return 1;
3088 #endif
3089 			}
3090 			break;
3091 		case '|':
3092 			done_word(dest, ctx);
3093 			if (next=='|') {
3094 				b_getch(input);
3095 				done_pipe(ctx,PIPE_OR);
3096 			} else {
3097 				/* we could pick up a file descriptor choice here
3098 				 * with redirect_opt_num(), but bash doesn't do it.
3099 				 * "echo foo 2| cat" yields "foo 2". */
3100 #ifndef __U_BOOT__
3101 				done_command(ctx);
3102 #else
3103 				syntax_err();
3104 				return 1;
3105 #endif
3106 			}
3107 			break;
3108 #ifndef __U_BOOT__
3109 		case '(':
3110 		case '{':
3111 			if (parse_group(dest, ctx, input, ch)!=0) return 1;
3112 			break;
3113 		case ')':
3114 		case '}':
3115 			syntax();   /* Proper use of this character caught by end_trigger */
3116 			return 1;
3117 			break;
3118 #endif
3119 		case SUBSTED_VAR_SYMBOL:
3120 			dest->nonnull = 1;
3121 			while (ch = b_getch(input), ch != EOF &&
3122 			    ch != SUBSTED_VAR_SYMBOL) {
3123 				debug_printf("subst, pass=%d\n", ch);
3124 				if (input->__promptme == 0)
3125 					return 1;
3126 				b_addchr(dest, ch);
3127 			}
3128 			debug_printf("subst, term=%d\n", ch);
3129 			if (ch == EOF) {
3130 				syntax();
3131 				return 1;
3132 			}
3133 			break;
3134 		default:
3135 			syntax();   /* this is really an internal logic error */
3136 			return 1;
3137 			}
3138 		}
3139 	}
3140 	/* complain if quote?  No, maybe we just finished a command substitution
3141 	 * that was quoted.  Example:
3142 	 * $ echo "`cat foo` plus more"
3143 	 * and we just got the EOF generated by the subshell that ran "cat foo"
3144 	 * The only real complaint is if we got an EOF when end_trigger != '\0',
3145 	 * that is, we were really supposed to get end_trigger, and never got
3146 	 * one before the EOF.  Can't use the standard "syntax error" return code,
3147 	 * so that parse_stream_outer can distinguish the EOF and exit smoothly. */
3148 	debug_printf("leaving parse_stream (EOF)\n");
3149 	if (end_trigger != '\0') return -1;
3150 	return 0;
3151 }
3152 
3153 static void mapset(const unsigned char *set, int code)
3154 {
3155 	const unsigned char *s;
3156 	for (s=set; *s; s++) map[*s] = code;
3157 }
3158 
3159 static void update_ifs_map(void)
3160 {
3161 	/* char *ifs and char map[256] are both globals. */
3162 	ifs = (uchar *)env_get("IFS");
3163 	if (ifs == NULL) ifs=(uchar *)" \t\n";
3164 	/* Precompute a list of 'flow through' behavior so it can be treated
3165 	 * quickly up front.  Computation is necessary because of IFS.
3166 	 * Special case handling of IFS == " \t\n" is not implemented.
3167 	 * The map[] array only really needs two bits each, and on most machines
3168 	 * that would be faster because of the reduced L1 cache footprint.
3169 	 */
3170 	memset(map,0,sizeof(map)); /* most characters flow through always */
3171 #ifndef __U_BOOT__
3172 	mapset((uchar *)"\\$'\"`", 3);      /* never flow through */
3173 	mapset((uchar *)"<>;&|(){}#", 1);   /* flow through if quoted */
3174 #else
3175 	{
3176 		uchar subst[2] = {SUBSTED_VAR_SYMBOL, 0};
3177 		mapset(subst, 3);       /* never flow through */
3178 	}
3179 	mapset((uchar *)"\\$'\"", 3);       /* never flow through */
3180 	mapset((uchar *)";&|#", 1);         /* flow through if quoted */
3181 #endif
3182 	mapset(ifs, 2);            /* also flow through if quoted */
3183 }
3184 
3185 /* most recursion does not come through here, the exeception is
3186  * from builtin_source() */
3187 static int parse_stream_outer(struct in_str *inp, int flag)
3188 {
3189 
3190 	struct p_context ctx;
3191 	o_string temp=NULL_O_STRING;
3192 	int rcode;
3193 #ifdef __U_BOOT__
3194 	int code = 1;
3195 #endif
3196 	do {
3197 		ctx.type = flag;
3198 		initialize_context(&ctx);
3199 		update_ifs_map();
3200 		if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING)) mapset((uchar *)";$&|", 0);
3201 		inp->promptmode=1;
3202 		rcode = parse_stream(&temp, &ctx, inp,
3203 				     flag & FLAG_CONT_ON_NEWLINE ? -1 : '\n');
3204 #ifdef __U_BOOT__
3205 		if (rcode == 1) flag_repeat = 0;
3206 #endif
3207 		if (rcode != 1 && ctx.old_flag != 0) {
3208 			syntax();
3209 #ifdef __U_BOOT__
3210 			flag_repeat = 0;
3211 #endif
3212 		}
3213 		if (rcode != 1 && ctx.old_flag == 0) {
3214 			done_word(&temp, &ctx);
3215 			done_pipe(&ctx,PIPE_SEQ);
3216 #ifndef __U_BOOT__
3217 			run_list(ctx.list_head);
3218 #else
3219 			code = run_list(ctx.list_head);
3220 			if (code == -2) {	/* exit */
3221 				b_free(&temp);
3222 				code = 0;
3223 				/* XXX hackish way to not allow exit from main loop */
3224 				if (inp->peek == file_peek) {
3225 					printf("exit not allowed from main input shell.\n");
3226 					continue;
3227 				}
3228 				break;
3229 			}
3230 			if (code == -1)
3231 			    flag_repeat = 0;
3232 #endif
3233 		} else {
3234 			if (ctx.old_flag != 0) {
3235 				free(ctx.stack);
3236 				b_reset(&temp);
3237 			}
3238 #ifdef __U_BOOT__
3239 			if (inp->__promptme == 0) printf("<INTERRUPT>\n");
3240 			inp->__promptme = 1;
3241 #endif
3242 			temp.nonnull = 0;
3243 			temp.quote = 0;
3244 			inp->p = NULL;
3245 			free_pipe_list(ctx.list_head,0);
3246 		}
3247 		b_free(&temp);
3248 	/* loop on syntax errors, return on EOF */
3249 	} while (rcode != -1 && !(flag & FLAG_EXIT_FROM_LOOP) &&
3250 		(inp->peek != static_peek || b_peek(inp)));
3251 #ifndef __U_BOOT__
3252 	return 0;
3253 #else
3254 	return (code != 0) ? 1 : 0;
3255 #endif /* __U_BOOT__ */
3256 }
3257 
3258 #ifndef __U_BOOT__
3259 static int parse_string_outer(const char *s, int flag)
3260 #else
3261 int parse_string_outer(const char *s, int flag)
3262 #endif	/* __U_BOOT__ */
3263 {
3264 	struct in_str input;
3265 #ifdef __U_BOOT__
3266 	char *p = NULL;
3267 	int rcode;
3268 	if (!s)
3269 		return 1;
3270 	if (!*s)
3271 		return 0;
3272 	if (!(p = strchr(s, '\n')) || *++p) {
3273 		p = xmalloc(strlen(s) + 2);
3274 		strcpy(p, s);
3275 		strcat(p, "\n");
3276 		setup_string_in_str(&input, p);
3277 		rcode = parse_stream_outer(&input, flag);
3278 		free(p);
3279 		return rcode;
3280 	} else {
3281 #endif
3282 	setup_string_in_str(&input, s);
3283 	return parse_stream_outer(&input, flag);
3284 #ifdef __U_BOOT__
3285 	}
3286 #endif
3287 }
3288 
3289 #ifndef __U_BOOT__
3290 static int parse_file_outer(FILE *f)
3291 #else
3292 int parse_file_outer(void)
3293 #endif
3294 {
3295 	int rcode;
3296 	struct in_str input;
3297 #ifndef __U_BOOT__
3298 	setup_file_in_str(&input, f);
3299 #else
3300 	setup_file_in_str(&input);
3301 #endif
3302 	rcode = parse_stream_outer(&input, FLAG_PARSE_SEMICOLON);
3303 	return rcode;
3304 }
3305 
3306 #ifdef __U_BOOT__
3307 #ifdef CONFIG_NEEDS_MANUAL_RELOC
3308 static void u_boot_hush_reloc(void)
3309 {
3310 	unsigned long addr;
3311 	struct reserved_combo *r;
3312 
3313 	for (r=reserved_list; r<reserved_list+NRES; r++) {
3314 		addr = (ulong) (r->literal) + gd->reloc_off;
3315 		r->literal = (char *)addr;
3316 	}
3317 }
3318 #endif
3319 
3320 int u_boot_hush_start(void)
3321 {
3322 	if (top_vars == NULL) {
3323 		top_vars = malloc(sizeof(struct variables));
3324 		top_vars->name = "HUSH_VERSION";
3325 		top_vars->value = "0.01";
3326 		top_vars->next = NULL;
3327 		top_vars->flg_export = 0;
3328 		top_vars->flg_read_only = 1;
3329 #ifdef CONFIG_NEEDS_MANUAL_RELOC
3330 		u_boot_hush_reloc();
3331 #endif
3332 	}
3333 	return 0;
3334 }
3335 
3336 static void *xmalloc(size_t size)
3337 {
3338 	void *p = NULL;
3339 
3340 	if (!(p = malloc(size))) {
3341 	    printf("ERROR : memory not allocated\n");
3342 	    for(;;);
3343 	}
3344 	return p;
3345 }
3346 
3347 static void *xrealloc(void *ptr, size_t size)
3348 {
3349 	void *p = NULL;
3350 
3351 	if (!(p = realloc(ptr, size))) {
3352 	    printf("ERROR : memory not allocated\n");
3353 	    for(;;);
3354 	}
3355 	return p;
3356 }
3357 #endif /* __U_BOOT__ */
3358 
3359 #ifndef __U_BOOT__
3360 /* Make sure we have a controlling tty.  If we get started under a job
3361  * aware app (like bash for example), make sure we are now in charge so
3362  * we don't fight over who gets the foreground */
3363 static void setup_job_control(void)
3364 {
3365 	static pid_t shell_pgrp;
3366 	/* Loop until we are in the foreground.  */
3367 	while (tcgetpgrp (shell_terminal) != (shell_pgrp = getpgrp ()))
3368 		kill (- shell_pgrp, SIGTTIN);
3369 
3370 	/* Ignore interactive and job-control signals.  */
3371 	signal(SIGINT, SIG_IGN);
3372 	signal(SIGQUIT, SIG_IGN);
3373 	signal(SIGTERM, SIG_IGN);
3374 	signal(SIGTSTP, SIG_IGN);
3375 	signal(SIGTTIN, SIG_IGN);
3376 	signal(SIGTTOU, SIG_IGN);
3377 	signal(SIGCHLD, SIG_IGN);
3378 
3379 	/* Put ourselves in our own process group.  */
3380 	setsid();
3381 	shell_pgrp = getpid ();
3382 	setpgid (shell_pgrp, shell_pgrp);
3383 
3384 	/* Grab control of the terminal.  */
3385 	tcsetpgrp(shell_terminal, shell_pgrp);
3386 }
3387 
3388 int hush_main(int argc, char * const *argv)
3389 {
3390 	int opt;
3391 	FILE *input;
3392 	char **e = environ;
3393 
3394 	/* XXX what should these be while sourcing /etc/profile? */
3395 	global_argc = argc;
3396 	global_argv = argv;
3397 
3398 	/* (re?) initialize globals.  Sometimes hush_main() ends up calling
3399 	 * hush_main(), therefore we cannot rely on the BSS to zero out this
3400 	 * stuff.  Reset these to 0 every time. */
3401 	ifs = NULL;
3402 	/* map[] is taken care of with call to update_ifs_map() */
3403 	fake_mode = 0;
3404 	interactive = 0;
3405 	close_me_head = NULL;
3406 	last_bg_pid = 0;
3407 	job_list = NULL;
3408 	last_jobid = 0;
3409 
3410 	/* Initialize some more globals to non-zero values */
3411 	set_cwd();
3412 #ifdef CONFIG_FEATURE_COMMAND_EDITING
3413 	cmdedit_set_initial_prompt();
3414 #else
3415 	PS1 = NULL;
3416 #endif
3417 	PS2 = "> ";
3418 
3419 	/* initialize our shell local variables with the values
3420 	 * currently living in the environment */
3421 	if (e) {
3422 		for (; *e; e++)
3423 			set_local_var(*e, 2);   /* without call putenv() */
3424 	}
3425 
3426 	last_return_code=EXIT_SUCCESS;
3427 
3428 
3429 	if (argv[0] && argv[0][0] == '-') {
3430 		debug_printf("\nsourcing /etc/profile\n");
3431 		if ((input = fopen("/etc/profile", "r")) != NULL) {
3432 			mark_open(fileno(input));
3433 			parse_file_outer(input);
3434 			mark_closed(fileno(input));
3435 			fclose(input);
3436 		}
3437 	}
3438 	input=stdin;
3439 
3440 	while ((opt = getopt(argc, argv, "c:xif")) > 0) {
3441 		switch (opt) {
3442 			case 'c':
3443 				{
3444 					global_argv = argv+optind;
3445 					global_argc = argc-optind;
3446 					opt = parse_string_outer(optarg, FLAG_PARSE_SEMICOLON);
3447 					goto final_return;
3448 				}
3449 				break;
3450 			case 'i':
3451 				interactive++;
3452 				break;
3453 			case 'f':
3454 				fake_mode++;
3455 				break;
3456 			default:
3457 #ifndef BB_VER
3458 				fprintf(stderr, "Usage: sh [FILE]...\n"
3459 						"   or: sh -c command [args]...\n\n");
3460 				exit(EXIT_FAILURE);
3461 #else
3462 				show_usage();
3463 #endif
3464 		}
3465 	}
3466 	/* A shell is interactive if the `-i' flag was given, or if all of
3467 	 * the following conditions are met:
3468 	 *	  no -c command
3469 	 *    no arguments remaining or the -s flag given
3470 	 *    standard input is a terminal
3471 	 *    standard output is a terminal
3472 	 *    Refer to Posix.2, the description of the `sh' utility. */
3473 	if (argv[optind]==NULL && input==stdin &&
3474 			isatty(fileno(stdin)) && isatty(fileno(stdout))) {
3475 		interactive++;
3476 	}
3477 
3478 	debug_printf("\ninteractive=%d\n", interactive);
3479 	if (interactive) {
3480 		/* Looks like they want an interactive shell */
3481 #ifndef CONFIG_FEATURE_SH_EXTRA_QUIET
3482 		printf( "\n\n" BB_BANNER " hush - the humble shell v0.01 (testing)\n");
3483 		printf( "Enter 'help' for a list of built-in commands.\n\n");
3484 #endif
3485 		setup_job_control();
3486 	}
3487 
3488 	if (argv[optind]==NULL) {
3489 		opt=parse_file_outer(stdin);
3490 		goto final_return;
3491 	}
3492 
3493 	debug_printf("\nrunning script '%s'\n", argv[optind]);
3494 	global_argv = argv+optind;
3495 	global_argc = argc-optind;
3496 	input = xfopen(argv[optind], "r");
3497 	opt = parse_file_outer(input);
3498 
3499 #ifdef CONFIG_FEATURE_CLEAN_UP
3500 	fclose(input);
3501 	if (cwd && cwd != unknown)
3502 		free((char*)cwd);
3503 	{
3504 		struct variables *cur, *tmp;
3505 		for(cur = top_vars; cur; cur = tmp) {
3506 			tmp = cur->next;
3507 			if (!cur->flg_read_only) {
3508 				free(cur->name);
3509 				free(cur->value);
3510 				free(cur);
3511 			}
3512 		}
3513 	}
3514 #endif
3515 
3516 final_return:
3517 	return(opt?opt:last_return_code);
3518 }
3519 #endif
3520 
3521 static char *insert_var_value(char *inp)
3522 {
3523 	return insert_var_value_sub(inp, 0);
3524 }
3525 
3526 static char *insert_var_value_sub(char *inp, int tag_subst)
3527 {
3528 	int res_str_len = 0;
3529 	int len;
3530 	int done = 0;
3531 	char *p, *p1, *res_str = NULL;
3532 
3533 	while ((p = strchr(inp, SPECIAL_VAR_SYMBOL))) {
3534 		/* check the beginning of the string for normal characters */
3535 		if (p != inp) {
3536 			/* copy any characters to the result string */
3537 			len = p - inp;
3538 			res_str = xrealloc(res_str, (res_str_len + len));
3539 			strncpy((res_str + res_str_len), inp, len);
3540 			res_str_len += len;
3541 		}
3542 		inp = ++p;
3543 		/* find the ending marker */
3544 		p = strchr(inp, SPECIAL_VAR_SYMBOL);
3545 		*p = '\0';
3546 		/* look up the value to substitute */
3547 		if ((p1 = lookup_param(inp))) {
3548 			if (tag_subst)
3549 				len = res_str_len + strlen(p1) + 2;
3550 			else
3551 				len = res_str_len + strlen(p1);
3552 			res_str = xrealloc(res_str, (1 + len));
3553 			if (tag_subst) {
3554 				/*
3555 				 * copy the variable value to the result
3556 				 * string
3557 				 */
3558 				strcpy((res_str + res_str_len + 1), p1);
3559 
3560 				/*
3561 				 * mark the replaced text to be accepted as
3562 				 * is
3563 				 */
3564 				res_str[res_str_len] = SUBSTED_VAR_SYMBOL;
3565 				res_str[res_str_len + 1 + strlen(p1)] =
3566 					SUBSTED_VAR_SYMBOL;
3567 			} else
3568 				/*
3569 				 * copy the variable value to the result
3570 				 * string
3571 				 */
3572 				strcpy((res_str + res_str_len), p1);
3573 
3574 			res_str_len = len;
3575 		}
3576 		*p = SPECIAL_VAR_SYMBOL;
3577 		inp = ++p;
3578 		done = 1;
3579 	}
3580 	if (done) {
3581 		res_str = xrealloc(res_str, (1 + res_str_len + strlen(inp)));
3582 		strcpy((res_str + res_str_len), inp);
3583 		while ((p = strchr(res_str, '\n'))) {
3584 			*p = ' ';
3585 		}
3586 	}
3587 	return (res_str == NULL) ? inp : res_str;
3588 }
3589 
3590 static char **make_list_in(char **inp, char *name)
3591 {
3592 	int len, i;
3593 	int name_len = strlen(name);
3594 	int n = 0;
3595 	char **list;
3596 	char *p1, *p2, *p3;
3597 
3598 	/* create list of variable values */
3599 	list = xmalloc(sizeof(*list));
3600 	for (i = 0; inp[i]; i++) {
3601 		p3 = insert_var_value(inp[i]);
3602 		p1 = p3;
3603 		while (*p1) {
3604 			if (*p1 == ' ') {
3605 				p1++;
3606 				continue;
3607 			}
3608 			if ((p2 = strchr(p1, ' '))) {
3609 				len = p2 - p1;
3610 			} else {
3611 				len = strlen(p1);
3612 				p2 = p1 + len;
3613 			}
3614 			/* we use n + 2 in realloc for list,because we add
3615 			 * new element and then we will add NULL element */
3616 			list = xrealloc(list, sizeof(*list) * (n + 2));
3617 			list[n] = xmalloc(2 + name_len + len);
3618 			strcpy(list[n], name);
3619 			strcat(list[n], "=");
3620 			strncat(list[n], p1, len);
3621 			list[n++][name_len + len + 1] = '\0';
3622 			p1 = p2;
3623 		}
3624 		if (p3 != inp[i]) free(p3);
3625 	}
3626 	list[n] = NULL;
3627 	return list;
3628 }
3629 
3630 /*
3631  * Make new string for parser
3632  * inp     - array of argument strings to flatten
3633  * nonnull - indicates argument was quoted when originally parsed
3634  */
3635 static char *make_string(char **inp, int *nonnull)
3636 {
3637 	char *p;
3638 	char *str = NULL;
3639 	int n;
3640 	int len = 2;
3641 	char *noeval_str;
3642 	int noeval = 0;
3643 
3644 	noeval_str = get_local_var("HUSH_NO_EVAL");
3645 	if (noeval_str != NULL && *noeval_str != '0' && *noeval_str != '\0')
3646 		noeval = 1;
3647 	for (n = 0; inp[n]; n++) {
3648 		p = insert_var_value_sub(inp[n], noeval);
3649 		str = xrealloc(str, (len + strlen(p) + (2 * nonnull[n])));
3650 		if (n) {
3651 			strcat(str, " ");
3652 		} else {
3653 			*str = '\0';
3654 		}
3655 		if (nonnull[n])
3656 			strcat(str, "'");
3657 		strcat(str, p);
3658 		if (nonnull[n])
3659 			strcat(str, "'");
3660 		len = strlen(str) + 3;
3661 		if (p != inp[n]) free(p);
3662 	}
3663 	len = strlen(str);
3664 	*(str + len) = '\n';
3665 	*(str + len + 1) = '\0';
3666 	return str;
3667 }
3668 
3669 #ifdef __U_BOOT__
3670 static int do_showvar(cmd_tbl_t *cmdtp, int flag, int argc,
3671 		      char * const argv[])
3672 {
3673 	int i, k;
3674 	int rcode = 0;
3675 	struct variables *cur;
3676 
3677 	if (argc == 1) {		/* Print all env variables	*/
3678 		for (cur = top_vars; cur; cur = cur->next) {
3679 			printf ("%s=%s\n", cur->name, cur->value);
3680 			if (ctrlc ()) {
3681 				puts ("\n ** Abort\n");
3682 				return 1;
3683 			}
3684 		}
3685 		return 0;
3686 	}
3687 	for (i = 1; i < argc; ++i) {	/* print single env variables	*/
3688 		char *name = argv[i];
3689 
3690 		k = -1;
3691 		for (cur = top_vars; cur; cur = cur->next) {
3692 			if(strcmp (cur->name, name) == 0) {
3693 				k = 0;
3694 				printf ("%s=%s\n", cur->name, cur->value);
3695 			}
3696 			if (ctrlc ()) {
3697 				puts ("\n ** Abort\n");
3698 				return 1;
3699 			}
3700 		}
3701 		if (k < 0) {
3702 			printf ("## Error: \"%s\" not defined\n", name);
3703 			rcode ++;
3704 		}
3705 	}
3706 	return rcode;
3707 }
3708 
3709 U_BOOT_CMD(
3710 	showvar, CONFIG_SYS_MAXARGS, 1,	do_showvar,
3711 	"print local hushshell variables",
3712 	"\n    - print values of all hushshell variables\n"
3713 	"showvar name ...\n"
3714 	"    - print value of hushshell variable 'name'"
3715 );
3716 
3717 #endif
3718 /****************************************************************************/
3719