xref: /openbmc/u-boot/common/cli_hush.c (revision dffceb4b)
1 /*
2  * sh.c -- a prototype Bourne shell grammar parser
3  *      Intended to follow the original Thompson and Ritchie
4  *      "small and simple is beautiful" philosophy, which
5  *      incidentally is a good match to today's BusyBox.
6  *
7  * Copyright (C) 2000,2001  Larry Doolittle  <larry@doolittle.boa.org>
8  *
9  * Credits:
10  *      The parser routines proper are all original material, first
11  *      written Dec 2000 and Jan 2001 by Larry Doolittle.
12  *      The execution engine, the builtins, and much of the underlying
13  *      support has been adapted from busybox-0.49pre's lash,
14  *      which is Copyright (C) 2000 by Lineo, Inc., and
15  *      written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>.
16  *      That, in turn, is based in part on ladsh.c, by Michael K. Johnson and
17  *      Erik W. Troan, which they placed in the public domain.  I don't know
18  *      how much of the Johnson/Troan code has survived the repeated rewrites.
19  * Other credits:
20  *      b_addchr() derived from similar w_addchar function in glibc-2.2
21  *      setup_redirect(), redirect_opt_num(), and big chunks of main()
22  *        and many builtins derived from contributions by Erik Andersen
23  *      miscellaneous bugfixes from Matt Kraai
24  *
25  * There are two big (and related) architecture differences between
26  * this parser and the lash parser.  One is that this version is
27  * actually designed from the ground up to understand nearly all
28  * of the Bourne grammar.  The second, consequential change is that
29  * the parser and input reader have been turned inside out.  Now,
30  * the parser is in control, and asks for input as needed.  The old
31  * way had the input reader in control, and it asked for parsing to
32  * take place as needed.  The new way makes it much easier to properly
33  * handle the recursion implicit in the various substitutions, especially
34  * across continuation lines.
35  *
36  * Bash grammar not implemented: (how many of these were in original sh?)
37  *      $@ (those sure look like weird quoting rules)
38  *      $_
39  *      ! negation operator for pipes
40  *      &> and >& redirection of stdout+stderr
41  *      Brace Expansion
42  *      Tilde Expansion
43  *      fancy forms of Parameter Expansion
44  *      aliases
45  *      Arithmetic Expansion
46  *      <(list) and >(list) Process Substitution
47  *      reserved words: case, esac, select, function
48  *      Here Documents ( << word )
49  *      Functions
50  * Major bugs:
51  *      job handling woefully incomplete and buggy
52  *      reserved word execution woefully incomplete and buggy
53  * to-do:
54  *      port selected bugfixes from post-0.49 busybox lash - done?
55  *      finish implementing reserved words: for, while, until, do, done
56  *      change { and } from special chars to reserved words
57  *      builtins: break, continue, eval, return, set, trap, ulimit
58  *      test magic exec
59  *      handle children going into background
60  *      clean up recognition of null pipes
61  *      check setting of global_argc and global_argv
62  *      control-C handling, probably with longjmp
63  *      follow IFS rules more precisely, including update semantics
64  *      figure out what to do with backslash-newline
65  *      explain why we use signal instead of sigaction
66  *      propagate syntax errors, die on resource errors?
67  *      continuation lines, both explicit and implicit - done?
68  *      memory leak finding and plugging - done?
69  *      more testing, especially quoting rules and redirection
70  *      document how quoting rules not precisely followed for variable assignments
71  *      maybe change map[] to use 2-bit entries
72  *      (eventually) remove all the printf's
73  *
74  * SPDX-License-Identifier:	GPL-2.0+
75  */
76 
77 #define __U_BOOT__
78 #ifdef __U_BOOT__
79 #include <malloc.h>         /* malloc, free, realloc*/
80 #include <linux/ctype.h>    /* isalpha, isdigit */
81 #include <common.h>        /* readline */
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__
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
374 static inline void debug_printf(const char *format, ...) { }
375 #endif
376 #define final_printf debug_printf
377 
378 #ifdef __U_BOOT__
379 static void syntax_err(void) {
380 	 printf("syntax error\n");
381 }
382 #else
383 static void __syntax(char *file, int line) {
384 	error_msg("syntax error %s:%d", file, line);
385 }
386 #define syntax() __syntax(__FILE__, __LINE__)
387 #endif
388 
389 #ifdef __U_BOOT__
390 static void *xmalloc(size_t size);
391 static void *xrealloc(void *ptr, size_t size);
392 #else
393 /* Index of subroutines: */
394 /*   function prototypes for builtins */
395 static int builtin_cd(struct child_prog *child);
396 static int builtin_env(struct child_prog *child);
397 static int builtin_eval(struct child_prog *child);
398 static int builtin_exec(struct child_prog *child);
399 static int builtin_exit(struct child_prog *child);
400 static int builtin_export(struct child_prog *child);
401 static int builtin_fg_bg(struct child_prog *child);
402 static int builtin_help(struct child_prog *child);
403 static int builtin_jobs(struct child_prog *child);
404 static int builtin_pwd(struct child_prog *child);
405 static int builtin_read(struct child_prog *child);
406 static int builtin_set(struct child_prog *child);
407 static int builtin_shift(struct child_prog *child);
408 static int builtin_source(struct child_prog *child);
409 static int builtin_umask(struct child_prog *child);
410 static int builtin_unset(struct child_prog *child);
411 static int builtin_not_written(struct child_prog *child);
412 #endif
413 /*   o_string manipulation: */
414 static int b_check_space(o_string *o, int len);
415 static int b_addchr(o_string *o, int ch);
416 static void b_reset(o_string *o);
417 static int b_addqchr(o_string *o, int ch, int quote);
418 #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 
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 */
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 */
559 static int builtin_cd(struct child_prog *child)
560 {
561 	char *newdir;
562 	if (child->argv[1] == NULL)
563 		newdir = getenv("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 */
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 */
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 */
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 */
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 */
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 */
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 */
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 */
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 */
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 */
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 */
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) */
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 
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 */
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 
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 
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 
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 
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 
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  */
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__
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 
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 
940 static int static_peek(struct in_str *i)
941 {
942 	return *i->p;
943 }
944 
945 #ifndef __U_BOOT__
946 static inline void cmdedit_set_initial_prompt(void)
947 {
948 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
949 	PS1 = NULL;
950 #else
951 	PS1 = getenv("PS1");
952 	if(PS1==0)
953 		PS1 = "\\w \\$ ";
954 #endif
955 }
956 
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 static void get_user_input(struct in_str *i)
978 {
979 #ifndef __U_BOOT__
980 	char *prompt_str;
981 	static char the_command[BUFSIZ];
982 
983 	setup_prompt_string(i->promptmode, &prompt_str);
984 #ifdef CONFIG_FEATURE_COMMAND_EDITING
985 	/*
986 	 ** enable command line editing only while a command line
987 	 ** is actually being read; otherwise, we'll end up bequeathing
988 	 ** atexit() handlers and other unwanted stuff to our
989 	 ** child processes (rob@sysgo.de)
990 	 */
991 	cmdedit_read_input(prompt_str, the_command);
992 #else
993 	fputs(prompt_str, stdout);
994 	fflush(stdout);
995 	the_command[0]=fgetc(i->file);
996 	the_command[1]='\0';
997 #endif
998 	fflush(stdout);
999 	i->p = the_command;
1000 #else
1001 	int n;
1002 	static char the_command[CONFIG_SYS_CBSIZE + 1];
1003 
1004 	bootretry_reset_cmd_timeout();
1005 	i->__promptme = 1;
1006 	if (i->promptmode == 1) {
1007 		n = cli_readline(CONFIG_SYS_PROMPT);
1008 	} else {
1009 		n = cli_readline(CONFIG_SYS_PROMPT_HUSH_PS2);
1010 	}
1011 #ifdef CONFIG_BOOT_RETRY_TIME
1012 	if (n == -2) {
1013 	  puts("\nTimeout waiting for command\n");
1014 #  ifdef CONFIG_RESET_TO_RETRY
1015 	  do_reset(NULL, 0, 0, NULL);
1016 #  else
1017 #	error "This currently only works with CONFIG_RESET_TO_RETRY enabled"
1018 #  endif
1019 	}
1020 #endif
1021 	if (n == -1 ) {
1022 		flag_repeat = 0;
1023 		i->__promptme = 0;
1024 	}
1025 	n = strlen(console_buffer);
1026 	console_buffer[n] = '\n';
1027 	console_buffer[n+1]= '\0';
1028 	if (had_ctrlc()) flag_repeat = 0;
1029 	clear_ctrlc();
1030 	do_repeat = 0;
1031 	if (i->promptmode == 1) {
1032 		if (console_buffer[0] == '\n'&& flag_repeat == 0) {
1033 			strcpy(the_command,console_buffer);
1034 		}
1035 		else {
1036 			if (console_buffer[0] != '\n') {
1037 				strcpy(the_command,console_buffer);
1038 				flag_repeat = 1;
1039 			}
1040 			else {
1041 				do_repeat = 1;
1042 			}
1043 		}
1044 		i->p = the_command;
1045 	}
1046 	else {
1047 		if (console_buffer[0] != '\n') {
1048 			if (strlen(the_command) + strlen(console_buffer)
1049 			    < CONFIG_SYS_CBSIZE) {
1050 				n = strlen(the_command);
1051 				the_command[n-1] = ' ';
1052 				strcpy(&the_command[n],console_buffer);
1053 			}
1054 			else {
1055 				the_command[0] = '\n';
1056 				the_command[1] = '\0';
1057 				flag_repeat = 0;
1058 			}
1059 		}
1060 		if (i->__promptme == 0) {
1061 			the_command[0] = '\n';
1062 			the_command[1] = '\0';
1063 		}
1064 		i->p = console_buffer;
1065 	}
1066 #endif
1067 }
1068 
1069 /* This is the magic location that prints prompts
1070  * and gets data back from the user */
1071 static int file_get(struct in_str *i)
1072 {
1073 	int ch;
1074 
1075 	ch = 0;
1076 	/* If there is data waiting, eat it up */
1077 	if (i->p && *i->p) {
1078 		ch = *i->p++;
1079 	} else {
1080 		/* need to double check i->file because we might be doing something
1081 		 * more complicated by now, like sourcing or substituting. */
1082 #ifndef __U_BOOT__
1083 		if (i->__promptme && interactive && i->file == stdin) {
1084 			while(! i->p || (interactive && strlen(i->p)==0) ) {
1085 #else
1086 			while(! i->p  || strlen(i->p)==0 ) {
1087 #endif
1088 				get_user_input(i);
1089 			}
1090 			i->promptmode=2;
1091 #ifndef __U_BOOT__
1092 			i->__promptme = 0;
1093 #endif
1094 			if (i->p && *i->p) {
1095 				ch = *i->p++;
1096 			}
1097 #ifndef __U_BOOT__
1098 		} else {
1099 			ch = fgetc(i->file);
1100 		}
1101 
1102 #endif
1103 		debug_printf("b_getch: got a %d\n", ch);
1104 	}
1105 #ifndef __U_BOOT__
1106 	if (ch == '\n') i->__promptme=1;
1107 #endif
1108 	return ch;
1109 }
1110 
1111 /* All the callers guarantee this routine will never be
1112  * used right after a newline, so prompting is not needed.
1113  */
1114 static int file_peek(struct in_str *i)
1115 {
1116 #ifndef __U_BOOT__
1117 	if (i->p && *i->p) {
1118 #endif
1119 		return *i->p;
1120 #ifndef __U_BOOT__
1121 	} else {
1122 		i->peek_buf[0] = fgetc(i->file);
1123 		i->peek_buf[1] = '\0';
1124 		i->p = i->peek_buf;
1125 		debug_printf("b_peek: got a %d\n", *i->p);
1126 		return *i->p;
1127 	}
1128 #endif
1129 }
1130 
1131 #ifndef __U_BOOT__
1132 static void setup_file_in_str(struct in_str *i, FILE *f)
1133 #else
1134 static void setup_file_in_str(struct in_str *i)
1135 #endif
1136 {
1137 	i->peek = file_peek;
1138 	i->get = file_get;
1139 	i->__promptme=1;
1140 	i->promptmode=1;
1141 #ifndef __U_BOOT__
1142 	i->file = f;
1143 #endif
1144 	i->p = NULL;
1145 }
1146 
1147 static void setup_string_in_str(struct in_str *i, const char *s)
1148 {
1149 	i->peek = static_peek;
1150 	i->get = static_get;
1151 	i->__promptme=1;
1152 	i->promptmode=1;
1153 	i->p = s;
1154 }
1155 
1156 #ifndef __U_BOOT__
1157 static void mark_open(int fd)
1158 {
1159 	struct close_me *new = xmalloc(sizeof(struct close_me));
1160 	new->fd = fd;
1161 	new->next = close_me_head;
1162 	close_me_head = new;
1163 }
1164 
1165 static void mark_closed(int fd)
1166 {
1167 	struct close_me *tmp;
1168 	if (close_me_head == NULL || close_me_head->fd != fd)
1169 		error_msg_and_die("corrupt close_me");
1170 	tmp = close_me_head;
1171 	close_me_head = close_me_head->next;
1172 	free(tmp);
1173 }
1174 
1175 static void close_all(void)
1176 {
1177 	struct close_me *c;
1178 	for (c=close_me_head; c; c=c->next) {
1179 		close(c->fd);
1180 	}
1181 	close_me_head = NULL;
1182 }
1183 
1184 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
1185  * and stderr if they are redirected. */
1186 static int setup_redirects(struct child_prog *prog, int squirrel[])
1187 {
1188 	int openfd, mode;
1189 	struct redir_struct *redir;
1190 
1191 	for (redir=prog->redirects; redir; redir=redir->next) {
1192 		if (redir->dup == -1 && redir->word.gl_pathv == NULL) {
1193 			/* something went wrong in the parse.  Pretend it didn't happen */
1194 			continue;
1195 		}
1196 		if (redir->dup == -1) {
1197 			mode=redir_table[redir->type].mode;
1198 			openfd = open(redir->word.gl_pathv[0], mode, 0666);
1199 			if (openfd < 0) {
1200 			/* this could get lost if stderr has been redirected, but
1201 			   bash and ash both lose it as well (though zsh doesn't!) */
1202 				perror_msg("error opening %s", redir->word.gl_pathv[0]);
1203 				return 1;
1204 			}
1205 		} else {
1206 			openfd = redir->dup;
1207 		}
1208 
1209 		if (openfd != redir->fd) {
1210 			if (squirrel && redir->fd < 3) {
1211 				squirrel[redir->fd] = dup(redir->fd);
1212 			}
1213 			if (openfd == -3) {
1214 				close(openfd);
1215 			} else {
1216 				dup2(openfd, redir->fd);
1217 				if (redir->dup == -1)
1218 					close (openfd);
1219 			}
1220 		}
1221 	}
1222 	return 0;
1223 }
1224 
1225 static void restore_redirects(int squirrel[])
1226 {
1227 	int i, fd;
1228 	for (i=0; i<3; i++) {
1229 		fd = squirrel[i];
1230 		if (fd != -1) {
1231 			/* No error checking.  I sure wouldn't know what
1232 			 * to do with an error if I found one! */
1233 			dup2(fd, i);
1234 			close(fd);
1235 		}
1236 	}
1237 }
1238 
1239 /* never returns */
1240 /* XXX no exit() here.  If you don't exec, use _exit instead.
1241  * The at_exit handlers apparently confuse the calling process,
1242  * in particular stdin handling.  Not sure why? */
1243 static void pseudo_exec(struct child_prog *child)
1244 {
1245 	int i, rcode;
1246 	char *p;
1247 	struct built_in_command *x;
1248 	if (child->argv) {
1249 		for (i=0; is_assignment(child->argv[i]); i++) {
1250 			debug_printf("pid %d environment modification: %s\n",getpid(),child->argv[i]);
1251 			p = insert_var_value(child->argv[i]);
1252 			putenv(strdup(p));
1253 			if (p != child->argv[i]) free(p);
1254 		}
1255 		child->argv+=i;  /* XXX this hack isn't so horrible, since we are about
1256 					to exit, and therefore don't need to keep data
1257 					structures consistent for free() use. */
1258 		/* If a variable is assigned in a forest, and nobody listens,
1259 		 * was it ever really set?
1260 		 */
1261 		if (child->argv[0] == NULL) {
1262 			_exit(EXIT_SUCCESS);
1263 		}
1264 
1265 		/*
1266 		 * Check if the command matches any of the builtins.
1267 		 * Depending on context, this might be redundant.  But it's
1268 		 * easier to waste a few CPU cycles than it is to figure out
1269 		 * if this is one of those cases.
1270 		 */
1271 		for (x = bltins; x->cmd; x++) {
1272 			if (strcmp(child->argv[0], x->cmd) == 0 ) {
1273 				debug_printf("builtin exec %s\n", child->argv[0]);
1274 				rcode = x->function(child);
1275 				fflush(stdout);
1276 				_exit(rcode);
1277 			}
1278 		}
1279 
1280 		/* Check if the command matches any busybox internal commands
1281 		 * ("applets") here.
1282 		 * FIXME: This feature is not 100% safe, since
1283 		 * BusyBox is not fully reentrant, so we have no guarantee the things
1284 		 * from the .bss are still zeroed, or that things from .data are still
1285 		 * at their defaults.  We could exec ourself from /proc/self/exe, but I
1286 		 * really dislike relying on /proc for things.  We could exec ourself
1287 		 * from global_argv[0], but if we are in a chroot, we may not be able
1288 		 * to find ourself... */
1289 #ifdef CONFIG_FEATURE_SH_STANDALONE_SHELL
1290 		{
1291 			int argc_l;
1292 			char** argv_l=child->argv;
1293 			char *name = child->argv[0];
1294 
1295 #ifdef CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN
1296 			/* Following discussions from November 2000 on the busybox mailing
1297 			 * list, the default configuration, (without
1298 			 * get_last_path_component()) lets the user force use of an
1299 			 * external command by specifying the full (with slashes) filename.
1300 			 * If you enable CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN then applets
1301 			 * _aways_ override external commands, so if you want to run
1302 			 * /bin/cat, it will use BusyBox cat even if /bin/cat exists on the
1303 			 * filesystem and is _not_ busybox.  Some systems may want this,
1304 			 * most do not.  */
1305 			name = get_last_path_component(name);
1306 #endif
1307 			/* Count argc for use in a second... */
1308 			for(argc_l=0;*argv_l!=NULL; argv_l++, argc_l++);
1309 			optind = 1;
1310 			debug_printf("running applet %s\n", name);
1311 			run_applet_by_name(name, argc_l, child->argv);
1312 		}
1313 #endif
1314 		debug_printf("exec of %s\n",child->argv[0]);
1315 		execvp(child->argv[0],child->argv);
1316 		perror_msg("couldn't exec: %s",child->argv[0]);
1317 		_exit(1);
1318 	} else if (child->group) {
1319 		debug_printf("runtime nesting to group\n");
1320 		interactive=0;    /* crucial!!!! */
1321 		rcode = run_list_real(child->group);
1322 		/* OK to leak memory by not calling free_pipe_list,
1323 		 * since this process is about to exit */
1324 		_exit(rcode);
1325 	} else {
1326 		/* Can happen.  See what bash does with ">foo" by itself. */
1327 		debug_printf("trying to pseudo_exec null command\n");
1328 		_exit(EXIT_SUCCESS);
1329 	}
1330 }
1331 
1332 static void insert_bg_job(struct pipe *pi)
1333 {
1334 	struct pipe *thejob;
1335 
1336 	/* Linear search for the ID of the job to use */
1337 	pi->jobid = 1;
1338 	for (thejob = job_list; thejob; thejob = thejob->next)
1339 		if (thejob->jobid >= pi->jobid)
1340 			pi->jobid = thejob->jobid + 1;
1341 
1342 	/* add thejob to the list of running jobs */
1343 	if (!job_list) {
1344 		thejob = job_list = xmalloc(sizeof(*thejob));
1345 	} else {
1346 		for (thejob = job_list; thejob->next; thejob = thejob->next) /* nothing */;
1347 		thejob->next = xmalloc(sizeof(*thejob));
1348 		thejob = thejob->next;
1349 	}
1350 
1351 	/* physically copy the struct job */
1352 	memcpy(thejob, pi, sizeof(struct pipe));
1353 	thejob->next = NULL;
1354 	thejob->running_progs = thejob->num_progs;
1355 	thejob->stopped_progs = 0;
1356 	thejob->text = xmalloc(BUFSIZ); /* cmdedit buffer size */
1357 
1358 	/*if (pi->progs[0] && pi->progs[0].argv && pi->progs[0].argv[0]) */
1359 	{
1360 		char *bar=thejob->text;
1361 		char **foo=pi->progs[0].argv;
1362 		while(foo && *foo) {
1363 			bar += sprintf(bar, "%s ", *foo++);
1364 		}
1365 	}
1366 
1367 	/* we don't wait for background thejobs to return -- append it
1368 	   to the list of backgrounded thejobs and leave it alone */
1369 	printf("[%d] %d\n", thejob->jobid, thejob->progs[0].pid);
1370 	last_bg_pid = thejob->progs[0].pid;
1371 	last_jobid = thejob->jobid;
1372 }
1373 
1374 /* remove a backgrounded job */
1375 static void remove_bg_job(struct pipe *pi)
1376 {
1377 	struct pipe *prev_pipe;
1378 
1379 	if (pi == job_list) {
1380 		job_list = pi->next;
1381 	} else {
1382 		prev_pipe = job_list;
1383 		while (prev_pipe->next != pi)
1384 			prev_pipe = prev_pipe->next;
1385 		prev_pipe->next = pi->next;
1386 	}
1387 	if (job_list)
1388 		last_jobid = job_list->jobid;
1389 	else
1390 		last_jobid = 0;
1391 
1392 	pi->stopped_progs = 0;
1393 	free_pipe(pi, 0);
1394 	free(pi);
1395 }
1396 
1397 /* Checks to see if any processes have exited -- if they
1398    have, figure out why and see if a job has completed */
1399 static int checkjobs(struct pipe* fg_pipe)
1400 {
1401 	int attributes;
1402 	int status;
1403 	int prognum = 0;
1404 	struct pipe *pi;
1405 	pid_t childpid;
1406 
1407 	attributes = WUNTRACED;
1408 	if (fg_pipe==NULL) {
1409 		attributes |= WNOHANG;
1410 	}
1411 
1412 	while ((childpid = waitpid(-1, &status, attributes)) > 0) {
1413 		if (fg_pipe) {
1414 			int i, rcode = 0;
1415 			for (i=0; i < fg_pipe->num_progs; i++) {
1416 				if (fg_pipe->progs[i].pid == childpid) {
1417 					if (i==fg_pipe->num_progs-1)
1418 						rcode=WEXITSTATUS(status);
1419 					(fg_pipe->num_progs)--;
1420 					return(rcode);
1421 				}
1422 			}
1423 		}
1424 
1425 		for (pi = job_list; pi; pi = pi->next) {
1426 			prognum = 0;
1427 			while (prognum < pi->num_progs && pi->progs[prognum].pid != childpid) {
1428 				prognum++;
1429 			}
1430 			if (prognum < pi->num_progs)
1431 				break;
1432 		}
1433 
1434 		if(pi==NULL) {
1435 			debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
1436 			continue;
1437 		}
1438 
1439 		if (WIFEXITED(status) || WIFSIGNALED(status)) {
1440 			/* child exited */
1441 			pi->running_progs--;
1442 			pi->progs[prognum].pid = 0;
1443 
1444 			if (!pi->running_progs) {
1445 				printf(JOB_STATUS_FORMAT, pi->jobid, "Done", pi->text);
1446 				remove_bg_job(pi);
1447 			}
1448 		} else {
1449 			/* child stopped */
1450 			pi->stopped_progs++;
1451 			pi->progs[prognum].is_stopped = 1;
1452 
1453 #if 0
1454 			/* Printing this stuff is a pain, since it tends to
1455 			 * overwrite the prompt an inconveinient moments.  So
1456 			 * don't do that.  */
1457 			if (pi->stopped_progs == pi->num_progs) {
1458 				printf("\n"JOB_STATUS_FORMAT, pi->jobid, "Stopped", pi->text);
1459 			}
1460 #endif
1461 		}
1462 	}
1463 
1464 	if (childpid == -1 && errno != ECHILD)
1465 		perror_msg("waitpid");
1466 
1467 	/* move the shell to the foreground */
1468 	/*if (interactive && tcsetpgrp(shell_terminal, getpgid(0))) */
1469 	/*	perror_msg("tcsetpgrp-2"); */
1470 	return -1;
1471 }
1472 
1473 /* Figure out our controlling tty, checking in order stderr,
1474  * stdin, and stdout.  If check_pgrp is set, also check that
1475  * we belong to the foreground process group associated with
1476  * that tty.  The value of shell_terminal is needed in order to call
1477  * tcsetpgrp(shell_terminal, ...); */
1478 void controlling_tty(int check_pgrp)
1479 {
1480 	pid_t curpgrp;
1481 
1482 	if ((curpgrp = tcgetpgrp(shell_terminal = 2)) < 0
1483 			&& (curpgrp = tcgetpgrp(shell_terminal = 0)) < 0
1484 			&& (curpgrp = tcgetpgrp(shell_terminal = 1)) < 0)
1485 		goto shell_terminal_error;
1486 
1487 	if (check_pgrp && curpgrp != getpgid(0))
1488 		goto shell_terminal_error;
1489 
1490 	return;
1491 
1492 shell_terminal_error:
1493 		shell_terminal = -1;
1494 		return;
1495 }
1496 #endif
1497 
1498 /* run_pipe_real() starts all the jobs, but doesn't wait for anything
1499  * to finish.  See checkjobs().
1500  *
1501  * return code is normally -1, when the caller has to wait for children
1502  * to finish to determine the exit status of the pipe.  If the pipe
1503  * is a simple builtin command, however, the action is done by the
1504  * time run_pipe_real returns, and the exit code is provided as the
1505  * return value.
1506  *
1507  * The input of the pipe is always stdin, the output is always
1508  * stdout.  The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
1509  * because it tries to avoid running the command substitution in
1510  * subshell, when that is in fact necessary.  The subshell process
1511  * now has its stdout directed to the input of the appropriate pipe,
1512  * so this routine is noticeably simpler.
1513  */
1514 static int run_pipe_real(struct pipe *pi)
1515 {
1516 	int i;
1517 #ifndef __U_BOOT__
1518 	int nextin, nextout;
1519 	int pipefds[2];				/* pipefds[0] is for reading */
1520 	struct child_prog *child;
1521 	struct built_in_command *x;
1522 	char *p;
1523 # if __GNUC__
1524 	/* Avoid longjmp clobbering */
1525 	(void) &i;
1526 	(void) &nextin;
1527 	(void) &nextout;
1528 	(void) &child;
1529 # endif
1530 #else
1531 	int nextin;
1532 	int flag = do_repeat ? CMD_FLAG_REPEAT : 0;
1533 	struct child_prog *child;
1534 	char *p;
1535 # if __GNUC__
1536 	/* Avoid longjmp clobbering */
1537 	(void) &i;
1538 	(void) &nextin;
1539 	(void) &child;
1540 # endif
1541 #endif	/* __U_BOOT__ */
1542 
1543 	nextin = 0;
1544 #ifndef __U_BOOT__
1545 	pi->pgrp = -1;
1546 #endif
1547 
1548 	/* Check if this is a simple builtin (not part of a pipe).
1549 	 * Builtins within pipes have to fork anyway, and are handled in
1550 	 * pseudo_exec.  "echo foo | read bar" doesn't work on bash, either.
1551 	 */
1552 	if (pi->num_progs == 1) child = & (pi->progs[0]);
1553 #ifndef __U_BOOT__
1554 	if (pi->num_progs == 1 && child->group && child->subshell == 0) {
1555 		int squirrel[] = {-1, -1, -1};
1556 		int rcode;
1557 		debug_printf("non-subshell grouping\n");
1558 		setup_redirects(child, squirrel);
1559 		/* XXX could we merge code with following builtin case,
1560 		 * by creating a pseudo builtin that calls run_list_real? */
1561 		rcode = run_list_real(child->group);
1562 		restore_redirects(squirrel);
1563 #else
1564 		if (pi->num_progs == 1 && child->group) {
1565 		int rcode;
1566 		debug_printf("non-subshell grouping\n");
1567 		rcode = run_list_real(child->group);
1568 #endif
1569 		return rcode;
1570 	} else if (pi->num_progs == 1 && pi->progs[0].argv != NULL) {
1571 		for (i=0; is_assignment(child->argv[i]); i++) { /* nothing */ }
1572 		if (i!=0 && child->argv[i]==NULL) {
1573 			/* assignments, but no command: set the local environment */
1574 			for (i=0; child->argv[i]!=NULL; i++) {
1575 
1576 				/* Ok, this case is tricky.  We have to decide if this is a
1577 				 * local variable, or an already exported variable.  If it is
1578 				 * already exported, we have to export the new value.  If it is
1579 				 * not exported, we need only set this as a local variable.
1580 				 * This junk is all to decide whether or not to export this
1581 				 * variable. */
1582 				int export_me=0;
1583 				char *name, *value;
1584 				name = xstrdup(child->argv[i]);
1585 				debug_printf("Local environment set: %s\n", name);
1586 				value = strchr(name, '=');
1587 				if (value)
1588 					*value=0;
1589 #ifndef __U_BOOT__
1590 				if ( get_local_var(name)) {
1591 					export_me=1;
1592 				}
1593 #endif
1594 				free(name);
1595 				p = insert_var_value(child->argv[i]);
1596 				set_local_var(p, export_me);
1597 				if (p != child->argv[i]) free(p);
1598 			}
1599 			return EXIT_SUCCESS;   /* don't worry about errors in set_local_var() yet */
1600 		}
1601 		for (i = 0; is_assignment(child->argv[i]); i++) {
1602 			p = insert_var_value(child->argv[i]);
1603 #ifndef __U_BOOT__
1604 			putenv(strdup(p));
1605 #else
1606 			set_local_var(p, 0);
1607 #endif
1608 			if (p != child->argv[i]) {
1609 				child->sp--;
1610 				free(p);
1611 			}
1612 		}
1613 		if (child->sp) {
1614 			char * str = NULL;
1615 
1616 			str = make_string(child->argv + i,
1617 					  child->argv_nonnull + i);
1618 			parse_string_outer(str, FLAG_EXIT_FROM_LOOP | FLAG_REPARSING);
1619 			free(str);
1620 			return last_return_code;
1621 		}
1622 #ifndef __U_BOOT__
1623 		for (x = bltins; x->cmd; x++) {
1624 			if (strcmp(child->argv[i], x->cmd) == 0 ) {
1625 				int squirrel[] = {-1, -1, -1};
1626 				int rcode;
1627 				if (x->function == builtin_exec && child->argv[i+1]==NULL) {
1628 					debug_printf("magic exec\n");
1629 					setup_redirects(child,NULL);
1630 					return EXIT_SUCCESS;
1631 				}
1632 				debug_printf("builtin inline %s\n", child->argv[0]);
1633 				/* XXX setup_redirects acts on file descriptors, not FILEs.
1634 				 * This is perfect for work that comes after exec().
1635 				 * Is it really safe for inline use?  Experimentally,
1636 				 * things seem to work with glibc. */
1637 				setup_redirects(child, squirrel);
1638 
1639 				child->argv += i;  /* XXX horrible hack */
1640 				rcode = x->function(child);
1641 				/* XXX restore hack so free() can work right */
1642 				child->argv -= i;
1643 				restore_redirects(squirrel);
1644 			}
1645 			return rcode;
1646 		}
1647 #else
1648 		/* check ";", because ,example , argv consist from
1649 		 * "help;flinfo" must not execute
1650 		 */
1651 		if (strchr(child->argv[i], ';')) {
1652 			printf("Unknown command '%s' - try 'help' or use "
1653 					"'run' command\n", child->argv[i]);
1654 			return -1;
1655 		}
1656 		/* Process the command */
1657 		return cmd_process(flag, child->argc, child->argv,
1658 				   &flag_repeat, NULL);
1659 #endif
1660 	}
1661 #ifndef __U_BOOT__
1662 
1663 	for (i = 0; i < pi->num_progs; i++) {
1664 		child = & (pi->progs[i]);
1665 
1666 		/* pipes are inserted between pairs of commands */
1667 		if ((i + 1) < pi->num_progs) {
1668 			if (pipe(pipefds)<0) perror_msg_and_die("pipe");
1669 			nextout = pipefds[1];
1670 		} else {
1671 			nextout=1;
1672 			pipefds[0] = -1;
1673 		}
1674 
1675 		/* XXX test for failed fork()? */
1676 		if (!(child->pid = fork())) {
1677 			/* Set the handling for job control signals back to the default.  */
1678 			signal(SIGINT, SIG_DFL);
1679 			signal(SIGQUIT, SIG_DFL);
1680 			signal(SIGTERM, SIG_DFL);
1681 			signal(SIGTSTP, SIG_DFL);
1682 			signal(SIGTTIN, SIG_DFL);
1683 			signal(SIGTTOU, SIG_DFL);
1684 			signal(SIGCHLD, SIG_DFL);
1685 
1686 			close_all();
1687 
1688 			if (nextin != 0) {
1689 				dup2(nextin, 0);
1690 				close(nextin);
1691 			}
1692 			if (nextout != 1) {
1693 				dup2(nextout, 1);
1694 				close(nextout);
1695 			}
1696 			if (pipefds[0]!=-1) {
1697 				close(pipefds[0]);  /* opposite end of our output pipe */
1698 			}
1699 
1700 			/* Like bash, explicit redirects override pipes,
1701 			 * and the pipe fd is available for dup'ing. */
1702 			setup_redirects(child,NULL);
1703 
1704 			if (interactive && pi->followup!=PIPE_BG) {
1705 				/* If we (the child) win the race, put ourselves in the process
1706 				 * group whose leader is the first process in this pipe. */
1707 				if (pi->pgrp < 0) {
1708 					pi->pgrp = getpid();
1709 				}
1710 				if (setpgid(0, pi->pgrp) == 0) {
1711 					tcsetpgrp(2, pi->pgrp);
1712 				}
1713 			}
1714 
1715 			pseudo_exec(child);
1716 		}
1717 
1718 
1719 		/* put our child in the process group whose leader is the
1720 		   first process in this pipe */
1721 		if (pi->pgrp < 0) {
1722 			pi->pgrp = child->pid;
1723 		}
1724 		/* Don't check for errors.  The child may be dead already,
1725 		 * in which case setpgid returns error code EACCES. */
1726 		setpgid(child->pid, pi->pgrp);
1727 
1728 		if (nextin != 0)
1729 			close(nextin);
1730 		if (nextout != 1)
1731 			close(nextout);
1732 
1733 		/* If there isn't another process, nextin is garbage
1734 		   but it doesn't matter */
1735 		nextin = pipefds[0];
1736 	}
1737 #endif
1738 	return -1;
1739 }
1740 
1741 static int run_list_real(struct pipe *pi)
1742 {
1743 	char *save_name = NULL;
1744 	char **list = NULL;
1745 	char **save_list = NULL;
1746 	struct pipe *rpipe;
1747 	int flag_rep = 0;
1748 #ifndef __U_BOOT__
1749 	int save_num_progs;
1750 #endif
1751 	int rcode=0, flag_skip=1;
1752 	int flag_restore = 0;
1753 	int if_code=0, next_if_code=0;  /* need double-buffer to handle elif */
1754 	reserved_style rmode, skip_more_in_this_rmode=RES_XXXX;
1755 	/* check syntax for "for" */
1756 	for (rpipe = pi; rpipe; rpipe = rpipe->next) {
1757 		if ((rpipe->r_mode == RES_IN ||
1758 		    rpipe->r_mode == RES_FOR) &&
1759 		    (rpipe->next == NULL)) {
1760 				syntax();
1761 #ifdef __U_BOOT__
1762 				flag_repeat = 0;
1763 #endif
1764 				return 1;
1765 		}
1766 		if ((rpipe->r_mode == RES_IN &&
1767 			(rpipe->next->r_mode == RES_IN &&
1768 			rpipe->next->progs->argv != NULL))||
1769 			(rpipe->r_mode == RES_FOR &&
1770 			rpipe->next->r_mode != RES_IN)) {
1771 				syntax();
1772 #ifdef __U_BOOT__
1773 				flag_repeat = 0;
1774 #endif
1775 				return 1;
1776 		}
1777 	}
1778 	for (; pi; pi = (flag_restore != 0) ? rpipe : pi->next) {
1779 		if (pi->r_mode == RES_WHILE || pi->r_mode == RES_UNTIL ||
1780 			pi->r_mode == RES_FOR) {
1781 #ifdef __U_BOOT__
1782 				/* check Ctrl-C */
1783 				ctrlc();
1784 				if ((had_ctrlc())) {
1785 					return 1;
1786 				}
1787 #endif
1788 				flag_restore = 0;
1789 				if (!rpipe) {
1790 					flag_rep = 0;
1791 					rpipe = pi;
1792 				}
1793 		}
1794 		rmode = pi->r_mode;
1795 		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);
1796 		if (rmode == skip_more_in_this_rmode && flag_skip) {
1797 			if (pi->followup == PIPE_SEQ) flag_skip=0;
1798 			continue;
1799 		}
1800 		flag_skip = 1;
1801 		skip_more_in_this_rmode = RES_XXXX;
1802 		if (rmode == RES_THEN || rmode == RES_ELSE) if_code = next_if_code;
1803 		if (rmode == RES_THEN &&  if_code) continue;
1804 		if (rmode == RES_ELSE && !if_code) continue;
1805 		if (rmode == RES_ELIF && !if_code) break;
1806 		if (rmode == RES_FOR && pi->num_progs) {
1807 			if (!list) {
1808 				/* if no variable values after "in" we skip "for" */
1809 				if (!pi->next->progs->argv) continue;
1810 				/* create list of variable values */
1811 				list = make_list_in(pi->next->progs->argv,
1812 					pi->progs->argv[0]);
1813 				save_list = list;
1814 				save_name = pi->progs->argv[0];
1815 				pi->progs->argv[0] = NULL;
1816 				flag_rep = 1;
1817 			}
1818 			if (!(*list)) {
1819 				free(pi->progs->argv[0]);
1820 				free(save_list);
1821 				list = NULL;
1822 				flag_rep = 0;
1823 				pi->progs->argv[0] = save_name;
1824 #ifndef __U_BOOT__
1825 				pi->progs->glob_result.gl_pathv[0] =
1826 					pi->progs->argv[0];
1827 #endif
1828 				continue;
1829 			} else {
1830 				/* insert new value from list for variable */
1831 				if (pi->progs->argv[0])
1832 					free(pi->progs->argv[0]);
1833 				pi->progs->argv[0] = *list++;
1834 #ifndef __U_BOOT__
1835 				pi->progs->glob_result.gl_pathv[0] =
1836 					pi->progs->argv[0];
1837 #endif
1838 			}
1839 		}
1840 		if (rmode == RES_IN) continue;
1841 		if (rmode == RES_DO) {
1842 			if (!flag_rep) continue;
1843 		}
1844 		if (rmode == RES_DONE) {
1845 			if (flag_rep) {
1846 				flag_restore = 1;
1847 			} else {
1848 				rpipe = NULL;
1849 			}
1850 		}
1851 		if (pi->num_progs == 0) continue;
1852 #ifndef __U_BOOT__
1853 		save_num_progs = pi->num_progs; /* save number of programs */
1854 #endif
1855 		rcode = run_pipe_real(pi);
1856 		debug_printf("run_pipe_real returned %d\n",rcode);
1857 #ifndef __U_BOOT__
1858 		if (rcode!=-1) {
1859 			/* We only ran a builtin: rcode was set by the return value
1860 			 * of run_pipe_real(), and we don't need to wait for anything. */
1861 		} else if (pi->followup==PIPE_BG) {
1862 			/* XXX check bash's behavior with nontrivial pipes */
1863 			/* XXX compute jobid */
1864 			/* XXX what does bash do with attempts to background builtins? */
1865 			insert_bg_job(pi);
1866 			rcode = EXIT_SUCCESS;
1867 		} else {
1868 			if (interactive) {
1869 				/* move the new process group into the foreground */
1870 				if (tcsetpgrp(shell_terminal, pi->pgrp) && errno != ENOTTY)
1871 					perror_msg("tcsetpgrp-3");
1872 				rcode = checkjobs(pi);
1873 				/* move the shell to the foreground */
1874 				if (tcsetpgrp(shell_terminal, getpgid(0)) && errno != ENOTTY)
1875 					perror_msg("tcsetpgrp-4");
1876 			} else {
1877 				rcode = checkjobs(pi);
1878 			}
1879 			debug_printf("checkjobs returned %d\n",rcode);
1880 		}
1881 		last_return_code=rcode;
1882 #else
1883 		if (rcode < -1) {
1884 			last_return_code = -rcode - 2;
1885 			return -2;	/* exit */
1886 		}
1887 		last_return_code=(rcode == 0) ? 0 : 1;
1888 #endif
1889 #ifndef __U_BOOT__
1890 		pi->num_progs = save_num_progs; /* restore number of programs */
1891 #endif
1892 		if ( rmode == RES_IF || rmode == RES_ELIF )
1893 			next_if_code=rcode;  /* can be overwritten a number of times */
1894 		if (rmode == RES_WHILE)
1895 			flag_rep = !last_return_code;
1896 		if (rmode == RES_UNTIL)
1897 			flag_rep = last_return_code;
1898 		if ( (rcode==EXIT_SUCCESS && pi->followup==PIPE_OR) ||
1899 		     (rcode!=EXIT_SUCCESS && pi->followup==PIPE_AND) )
1900 			skip_more_in_this_rmode=rmode;
1901 #ifndef __U_BOOT__
1902 		checkjobs(NULL);
1903 #endif
1904 	}
1905 	return rcode;
1906 }
1907 
1908 /* broken, of course, but OK for testing */
1909 static char *indenter(int i)
1910 {
1911 	static char blanks[]="                                    ";
1912 	return &blanks[sizeof(blanks)-i-1];
1913 }
1914 
1915 /* return code is the exit status of the pipe */
1916 static int free_pipe(struct pipe *pi, int indent)
1917 {
1918 	char **p;
1919 	struct child_prog *child;
1920 #ifndef __U_BOOT__
1921 	struct redir_struct *r, *rnext;
1922 #endif
1923 	int a, i, ret_code=0;
1924 	char *ind = indenter(indent);
1925 
1926 #ifndef __U_BOOT__
1927 	if (pi->stopped_progs > 0)
1928 		return ret_code;
1929 	final_printf("%s run pipe: (pid %d)\n",ind,getpid());
1930 #endif
1931 	for (i=0; i<pi->num_progs; i++) {
1932 		child = &pi->progs[i];
1933 		final_printf("%s  command %d:\n",ind,i);
1934 		if (child->argv) {
1935 			for (a=0,p=child->argv; *p; a++,p++) {
1936 				final_printf("%s   argv[%d] = %s\n",ind,a,*p);
1937 			}
1938 #ifndef __U_BOOT__
1939 			globfree(&child->glob_result);
1940 #else
1941 			for (a = 0; a < child->argc; a++) {
1942 				free(child->argv[a]);
1943 			}
1944 			free(child->argv);
1945 			free(child->argv_nonnull);
1946 			child->argc = 0;
1947 #endif
1948 			child->argv=NULL;
1949 		} else if (child->group) {
1950 #ifndef __U_BOOT__
1951 			final_printf("%s   begin group (subshell:%d)\n",ind, child->subshell);
1952 #endif
1953 			ret_code = free_pipe_list(child->group,indent+3);
1954 			final_printf("%s   end group\n",ind);
1955 		} else {
1956 			final_printf("%s   (nil)\n",ind);
1957 		}
1958 #ifndef __U_BOOT__
1959 		for (r=child->redirects; r; r=rnext) {
1960 			final_printf("%s   redirect %d%s", ind, r->fd, redir_table[r->type].descrip);
1961 			if (r->dup == -1) {
1962 				/* guard against the case >$FOO, where foo is unset or blank */
1963 				if (r->word.gl_pathv) {
1964 					final_printf(" %s\n", *r->word.gl_pathv);
1965 					globfree(&r->word);
1966 				}
1967 			} else {
1968 				final_printf("&%d\n", r->dup);
1969 			}
1970 			rnext=r->next;
1971 			free(r);
1972 		}
1973 		child->redirects=NULL;
1974 #endif
1975 	}
1976 	free(pi->progs);   /* children are an array, they get freed all at once */
1977 	pi->progs=NULL;
1978 	return ret_code;
1979 }
1980 
1981 static int free_pipe_list(struct pipe *head, int indent)
1982 {
1983 	int rcode=0;   /* if list has no members */
1984 	struct pipe *pi, *next;
1985 	char *ind = indenter(indent);
1986 	for (pi=head; pi; pi=next) {
1987 		final_printf("%s pipe reserved mode %d\n", ind, pi->r_mode);
1988 		rcode = free_pipe(pi, indent);
1989 		final_printf("%s pipe followup code %d\n", ind, pi->followup);
1990 		next=pi->next;
1991 		pi->next=NULL;
1992 		free(pi);
1993 	}
1994 	return rcode;
1995 }
1996 
1997 /* Select which version we will use */
1998 static int run_list(struct pipe *pi)
1999 {
2000 	int rcode=0;
2001 #ifndef __U_BOOT__
2002 	if (fake_mode==0) {
2003 #endif
2004 		rcode = run_list_real(pi);
2005 #ifndef __U_BOOT__
2006 	}
2007 #endif
2008 	/* free_pipe_list has the side effect of clearing memory
2009 	 * In the long run that function can be merged with run_list_real,
2010 	 * but doing that now would hobble the debugging effort. */
2011 	free_pipe_list(pi,0);
2012 	return rcode;
2013 }
2014 
2015 /* The API for glob is arguably broken.  This routine pushes a non-matching
2016  * string into the output structure, removing non-backslashed backslashes.
2017  * If someone can prove me wrong, by performing this function within the
2018  * original glob(3) api, feel free to rewrite this routine into oblivion.
2019  * Return code (0 vs. GLOB_NOSPACE) matches glob(3).
2020  * XXX broken if the last character is '\\', check that before calling.
2021  */
2022 #ifndef __U_BOOT__
2023 static int globhack(const char *src, int flags, glob_t *pglob)
2024 {
2025 	int cnt=0, pathc;
2026 	const char *s;
2027 	char *dest;
2028 	for (cnt=1, s=src; s && *s; s++) {
2029 		if (*s == '\\') s++;
2030 		cnt++;
2031 	}
2032 	dest = malloc(cnt);
2033 	if (!dest) return GLOB_NOSPACE;
2034 	if (!(flags & GLOB_APPEND)) {
2035 		pglob->gl_pathv=NULL;
2036 		pglob->gl_pathc=0;
2037 		pglob->gl_offs=0;
2038 		pglob->gl_offs=0;
2039 	}
2040 	pathc = ++pglob->gl_pathc;
2041 	pglob->gl_pathv = realloc(pglob->gl_pathv, (pathc+1)*sizeof(*pglob->gl_pathv));
2042 	if (pglob->gl_pathv == NULL) return GLOB_NOSPACE;
2043 	pglob->gl_pathv[pathc-1]=dest;
2044 	pglob->gl_pathv[pathc]=NULL;
2045 	for (s=src; s && *s; s++, dest++) {
2046 		if (*s == '\\') s++;
2047 		*dest = *s;
2048 	}
2049 	*dest='\0';
2050 	return 0;
2051 }
2052 
2053 /* XXX broken if the last character is '\\', check that before calling */
2054 static int glob_needed(const char *s)
2055 {
2056 	for (; *s; s++) {
2057 		if (*s == '\\') s++;
2058 		if (strchr("*[?",*s)) return 1;
2059 	}
2060 	return 0;
2061 }
2062 
2063 #if 0
2064 static void globprint(glob_t *pglob)
2065 {
2066 	int i;
2067 	debug_printf("glob_t at %p:\n", pglob);
2068 	debug_printf("  gl_pathc=%d  gl_pathv=%p  gl_offs=%d  gl_flags=%d\n",
2069 		pglob->gl_pathc, pglob->gl_pathv, pglob->gl_offs, pglob->gl_flags);
2070 	for (i=0; i<pglob->gl_pathc; i++)
2071 		debug_printf("pglob->gl_pathv[%d] = %p = %s\n", i,
2072 			pglob->gl_pathv[i], pglob->gl_pathv[i]);
2073 }
2074 #endif
2075 
2076 static int xglob(o_string *dest, int flags, glob_t *pglob)
2077 {
2078 	int gr;
2079 
2080 	/* short-circuit for null word */
2081 	/* we can code this better when the debug_printf's are gone */
2082 	if (dest->length == 0) {
2083 		if (dest->nonnull) {
2084 			/* bash man page calls this an "explicit" null */
2085 			gr = globhack(dest->data, flags, pglob);
2086 			debug_printf("globhack returned %d\n",gr);
2087 		} else {
2088 			return 0;
2089 		}
2090 	} else if (glob_needed(dest->data)) {
2091 		gr = glob(dest->data, flags, NULL, pglob);
2092 		debug_printf("glob returned %d\n",gr);
2093 		if (gr == GLOB_NOMATCH) {
2094 			/* quote removal, or more accurately, backslash removal */
2095 			gr = globhack(dest->data, flags, pglob);
2096 			debug_printf("globhack returned %d\n",gr);
2097 		}
2098 	} else {
2099 		gr = globhack(dest->data, flags, pglob);
2100 		debug_printf("globhack returned %d\n",gr);
2101 	}
2102 	if (gr == GLOB_NOSPACE)
2103 		error_msg_and_die("out of memory during glob");
2104 	if (gr != 0) { /* GLOB_ABORTED ? */
2105 		error_msg("glob(3) error %d",gr);
2106 	}
2107 	/* globprint(glob_target); */
2108 	return gr;
2109 }
2110 #endif
2111 
2112 #ifdef __U_BOOT__
2113 static char *get_dollar_var(char ch);
2114 #endif
2115 
2116 /* This is used to get/check local shell variables */
2117 char *get_local_var(const char *s)
2118 {
2119 	struct variables *cur;
2120 
2121 	if (!s)
2122 		return NULL;
2123 
2124 #ifdef __U_BOOT__
2125 	if (*s == '$')
2126 		return get_dollar_var(s[1]);
2127 #endif
2128 
2129 	for (cur = top_vars; cur; cur=cur->next)
2130 		if(strcmp(cur->name, s)==0)
2131 			return cur->value;
2132 	return NULL;
2133 }
2134 
2135 /* This is used to set local shell variables
2136    flg_export==0 if only local (not exporting) variable
2137    flg_export==1 if "new" exporting environ
2138    flg_export>1  if current startup environ (not call putenv()) */
2139 int set_local_var(const char *s, int flg_export)
2140 {
2141 	char *name, *value;
2142 	int result=0;
2143 	struct variables *cur;
2144 
2145 #ifdef __U_BOOT__
2146 	/* might be possible! */
2147 	if (!isalpha(*s))
2148 		return -1;
2149 #endif
2150 
2151 	name=strdup(s);
2152 
2153 #ifdef __U_BOOT__
2154 	if (getenv(name) != NULL) {
2155 		printf ("ERROR: "
2156 				"There is a global environment variable with the same name.\n");
2157 		free(name);
2158 		return -1;
2159 	}
2160 #endif
2161 	/* Assume when we enter this function that we are already in
2162 	 * NAME=VALUE format.  So the first order of business is to
2163 	 * split 's' on the '=' into 'name' and 'value' */
2164 	value = strchr(name, '=');
2165 	if (value == NULL || *(value + 1) == 0) {
2166 		free(name);
2167 		return -1;
2168 	}
2169 	*value++ = 0;
2170 
2171 	for(cur = top_vars; cur; cur = cur->next) {
2172 		if(strcmp(cur->name, name)==0)
2173 			break;
2174 	}
2175 
2176 	if(cur) {
2177 		if(strcmp(cur->value, value)==0) {
2178 			if(flg_export>0 && cur->flg_export==0)
2179 				cur->flg_export=flg_export;
2180 			else
2181 				result++;
2182 		} else {
2183 			if(cur->flg_read_only) {
2184 				error_msg("%s: readonly variable", name);
2185 				result = -1;
2186 			} else {
2187 				if(flg_export>0 || cur->flg_export>1)
2188 					cur->flg_export=1;
2189 				free(cur->value);
2190 
2191 				cur->value = strdup(value);
2192 			}
2193 		}
2194 	} else {
2195 		cur = malloc(sizeof(struct variables));
2196 		if(!cur) {
2197 			result = -1;
2198 		} else {
2199 			cur->name = strdup(name);
2200 			if (cur->name == NULL) {
2201 				free(cur);
2202 				result = -1;
2203 			} else {
2204 				struct variables *bottom = top_vars;
2205 				cur->value = strdup(value);
2206 				cur->next = NULL;
2207 				cur->flg_export = flg_export;
2208 				cur->flg_read_only = 0;
2209 				while(bottom->next) bottom=bottom->next;
2210 				bottom->next = cur;
2211 			}
2212 		}
2213 	}
2214 
2215 #ifndef __U_BOOT__
2216 	if(result==0 && cur->flg_export==1) {
2217 		*(value-1) = '=';
2218 		result = putenv(name);
2219 	} else {
2220 #endif
2221 		free(name);
2222 #ifndef __U_BOOT__
2223 		if(result>0)            /* equivalent to previous set */
2224 			result = 0;
2225 	}
2226 #endif
2227 	return result;
2228 }
2229 
2230 void unset_local_var(const char *name)
2231 {
2232 	struct variables *cur;
2233 
2234 	if (name) {
2235 		for (cur = top_vars; cur; cur=cur->next) {
2236 			if(strcmp(cur->name, name)==0)
2237 				break;
2238 		}
2239 		if (cur != NULL) {
2240 			struct variables *next = top_vars;
2241 			if(cur->flg_read_only) {
2242 				error_msg("%s: readonly variable", name);
2243 				return;
2244 			} else {
2245 #ifndef __U_BOOT__
2246 				if(cur->flg_export)
2247 					unsetenv(cur->name);
2248 #endif
2249 				free(cur->name);
2250 				free(cur->value);
2251 				while (next->next != cur)
2252 					next = next->next;
2253 				next->next = cur->next;
2254 			}
2255 			free(cur);
2256 		}
2257 	}
2258 }
2259 
2260 static int is_assignment(const char *s)
2261 {
2262 	if (s == NULL)
2263 		return 0;
2264 
2265 	if (!isalpha(*s)) return 0;
2266 	++s;
2267 	while(isalnum(*s) || *s=='_') ++s;
2268 	return *s=='=';
2269 }
2270 
2271 #ifndef __U_BOOT__
2272 /* the src parameter allows us to peek forward to a possible &n syntax
2273  * for file descriptor duplication, e.g., "2>&1".
2274  * Return code is 0 normally, 1 if a syntax error is detected in src.
2275  * Resource errors (in xmalloc) cause the process to exit */
2276 static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
2277 	struct in_str *input)
2278 {
2279 	struct child_prog *child=ctx->child;
2280 	struct redir_struct *redir = child->redirects;
2281 	struct redir_struct *last_redir=NULL;
2282 
2283 	/* Create a new redir_struct and drop it onto the end of the linked list */
2284 	while(redir) {
2285 		last_redir=redir;
2286 		redir=redir->next;
2287 	}
2288 	redir = xmalloc(sizeof(struct redir_struct));
2289 	redir->next=NULL;
2290 	redir->word.gl_pathv=NULL;
2291 	if (last_redir) {
2292 		last_redir->next=redir;
2293 	} else {
2294 		child->redirects=redir;
2295 	}
2296 
2297 	redir->type=style;
2298 	redir->fd= (fd==-1) ? redir_table[style].default_fd : fd ;
2299 
2300 	debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
2301 
2302 	/* Check for a '2>&1' type redirect */
2303 	redir->dup = redirect_dup_num(input);
2304 	if (redir->dup == -2) return 1;  /* syntax error */
2305 	if (redir->dup != -1) {
2306 		/* Erik had a check here that the file descriptor in question
2307 		 * is legit; I postpone that to "run time"
2308 		 * A "-" representation of "close me" shows up as a -3 here */
2309 		debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
2310 	} else {
2311 		/* We do _not_ try to open the file that src points to,
2312 		 * since we need to return and let src be expanded first.
2313 		 * Set ctx->pending_redirect, so we know what to do at the
2314 		 * end of the next parsed word.
2315 		 */
2316 		ctx->pending_redirect = redir;
2317 	}
2318 	return 0;
2319 }
2320 #endif
2321 
2322 static struct pipe *new_pipe(void)
2323 {
2324 	struct pipe *pi;
2325 	pi = xmalloc(sizeof(struct pipe));
2326 	pi->num_progs = 0;
2327 	pi->progs = NULL;
2328 	pi->next = NULL;
2329 	pi->followup = 0;  /* invalid */
2330 	pi->r_mode = RES_NONE;
2331 	return pi;
2332 }
2333 
2334 static void initialize_context(struct p_context *ctx)
2335 {
2336 	ctx->pipe=NULL;
2337 #ifndef __U_BOOT__
2338 	ctx->pending_redirect=NULL;
2339 #endif
2340 	ctx->child=NULL;
2341 	ctx->list_head=new_pipe();
2342 	ctx->pipe=ctx->list_head;
2343 	ctx->w=RES_NONE;
2344 	ctx->stack=NULL;
2345 #ifdef __U_BOOT__
2346 	ctx->old_flag=0;
2347 #endif
2348 	done_command(ctx);   /* creates the memory for working child */
2349 }
2350 
2351 /* normal return is 0
2352  * if a reserved word is found, and processed, return 1
2353  * should handle if, then, elif, else, fi, for, while, until, do, done.
2354  * case, function, and select are obnoxious, save those for later.
2355  */
2356 struct reserved_combo {
2357 	char *literal;
2358 	int code;
2359 	long flag;
2360 };
2361 /* Mostly a list of accepted follow-up reserved words.
2362  * FLAG_END means we are done with the sequence, and are ready
2363  * to turn the compound list into a command.
2364  * FLAG_START means the word must start a new compound list.
2365  */
2366 static struct reserved_combo reserved_list[] = {
2367 	{ "if",    RES_IF,    FLAG_THEN | FLAG_START },
2368 	{ "then",  RES_THEN,  FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2369 	{ "elif",  RES_ELIF,  FLAG_THEN },
2370 	{ "else",  RES_ELSE,  FLAG_FI   },
2371 	{ "fi",    RES_FI,    FLAG_END  },
2372 	{ "for",   RES_FOR,   FLAG_IN   | FLAG_START },
2373 	{ "while", RES_WHILE, FLAG_DO   | FLAG_START },
2374 	{ "until", RES_UNTIL, FLAG_DO   | FLAG_START },
2375 	{ "in",    RES_IN,    FLAG_DO   },
2376 	{ "do",    RES_DO,    FLAG_DONE },
2377 	{ "done",  RES_DONE,  FLAG_END  }
2378 };
2379 #define NRES (sizeof(reserved_list)/sizeof(struct reserved_combo))
2380 
2381 static int reserved_word(o_string *dest, struct p_context *ctx)
2382 {
2383 	struct reserved_combo *r;
2384 	for (r=reserved_list;
2385 		r<reserved_list+NRES; r++) {
2386 		if (strcmp(dest->data, r->literal) == 0) {
2387 			debug_printf("found reserved word %s, code %d\n",r->literal,r->code);
2388 			if (r->flag & FLAG_START) {
2389 				struct p_context *new = xmalloc(sizeof(struct p_context));
2390 				debug_printf("push stack\n");
2391 				if (ctx->w == RES_IN || ctx->w == RES_FOR) {
2392 					syntax();
2393 					free(new);
2394 					ctx->w = RES_SNTX;
2395 					b_reset(dest);
2396 					return 1;
2397 				}
2398 				*new = *ctx;   /* physical copy */
2399 				initialize_context(ctx);
2400 				ctx->stack=new;
2401 			} else if ( ctx->w == RES_NONE || ! (ctx->old_flag & (1<<r->code))) {
2402 				syntax();
2403 				ctx->w = RES_SNTX;
2404 				b_reset(dest);
2405 				return 1;
2406 			}
2407 			ctx->w=r->code;
2408 			ctx->old_flag = r->flag;
2409 			if (ctx->old_flag & FLAG_END) {
2410 				struct p_context *old;
2411 				debug_printf("pop stack\n");
2412 				done_pipe(ctx,PIPE_SEQ);
2413 				old = ctx->stack;
2414 				old->child->group = ctx->list_head;
2415 #ifndef __U_BOOT__
2416 				old->child->subshell = 0;
2417 #endif
2418 				*ctx = *old;   /* physical copy */
2419 				free(old);
2420 			}
2421 			b_reset (dest);
2422 			return 1;
2423 		}
2424 	}
2425 	return 0;
2426 }
2427 
2428 /* normal return is 0.
2429  * Syntax or xglob errors return 1. */
2430 static int done_word(o_string *dest, struct p_context *ctx)
2431 {
2432 	struct child_prog *child=ctx->child;
2433 #ifndef __U_BOOT__
2434 	glob_t *glob_target;
2435 	int gr, flags = 0;
2436 #else
2437 	char *str, *s;
2438 	int argc, cnt;
2439 #endif
2440 
2441 	debug_printf("done_word: %s %p\n", dest->data, child);
2442 	if (dest->length == 0 && !dest->nonnull) {
2443 		debug_printf("  true null, ignored\n");
2444 		return 0;
2445 	}
2446 #ifndef __U_BOOT__
2447 	if (ctx->pending_redirect) {
2448 		glob_target = &ctx->pending_redirect->word;
2449 	} else {
2450 #endif
2451 		if (child->group) {
2452 			syntax();
2453 			return 1;  /* syntax error, groups and arglists don't mix */
2454 		}
2455 		if (!child->argv && (ctx->type & FLAG_PARSE_SEMICOLON)) {
2456 			debug_printf("checking %s for reserved-ness\n",dest->data);
2457 			if (reserved_word(dest,ctx)) return ctx->w==RES_SNTX;
2458 		}
2459 #ifndef __U_BOOT__
2460 		glob_target = &child->glob_result;
2461 		if (child->argv) flags |= GLOB_APPEND;
2462 #else
2463 		for (cnt = 1, s = dest->data; s && *s; s++) {
2464 			if (*s == '\\') s++;
2465 			cnt++;
2466 		}
2467 		str = malloc(cnt);
2468 		if (!str) return 1;
2469 		if ( child->argv == NULL) {
2470 			child->argc=0;
2471 		}
2472 		argc = ++child->argc;
2473 		child->argv = realloc(child->argv, (argc+1)*sizeof(*child->argv));
2474 		if (child->argv == NULL) {
2475 			free(str);
2476 			return 1;
2477 		}
2478 		child->argv_nonnull = realloc(child->argv_nonnull,
2479 					(argc+1)*sizeof(*child->argv_nonnull));
2480 		if (child->argv_nonnull == NULL) {
2481 			free(str);
2482 			return 1;
2483 		}
2484 		child->argv[argc-1]=str;
2485 		child->argv_nonnull[argc-1] = dest->nonnull;
2486 		child->argv[argc]=NULL;
2487 		child->argv_nonnull[argc] = 0;
2488 		for (s = dest->data; s && *s; s++,str++) {
2489 			if (*s == '\\') s++;
2490 			*str = *s;
2491 		}
2492 		*str = '\0';
2493 #endif
2494 #ifndef __U_BOOT__
2495 	}
2496 	gr = xglob(dest, flags, glob_target);
2497 	if (gr != 0) return 1;
2498 #endif
2499 
2500 	b_reset(dest);
2501 #ifndef __U_BOOT__
2502 	if (ctx->pending_redirect) {
2503 		ctx->pending_redirect=NULL;
2504 		if (glob_target->gl_pathc != 1) {
2505 			error_msg("ambiguous redirect");
2506 			return 1;
2507 		}
2508 	} else {
2509 		child->argv = glob_target->gl_pathv;
2510 	}
2511 #endif
2512 	if (ctx->w == RES_FOR) {
2513 		done_word(dest,ctx);
2514 		done_pipe(ctx,PIPE_SEQ);
2515 	}
2516 	return 0;
2517 }
2518 
2519 /* The only possible error here is out of memory, in which case
2520  * xmalloc exits. */
2521 static int done_command(struct p_context *ctx)
2522 {
2523 	/* The child is really already in the pipe structure, so
2524 	 * advance the pipe counter and make a new, null child.
2525 	 * Only real trickiness here is that the uncommitted
2526 	 * child structure, to which ctx->child points, is not
2527 	 * counted in pi->num_progs. */
2528 	struct pipe *pi=ctx->pipe;
2529 	struct child_prog *prog=ctx->child;
2530 
2531 	if (prog && prog->group == NULL
2532 		 && prog->argv == NULL
2533 #ifndef __U_BOOT__
2534 		 && prog->redirects == NULL) {
2535 #else
2536 										) {
2537 #endif
2538 		debug_printf("done_command: skipping null command\n");
2539 		return 0;
2540 	} else if (prog) {
2541 		pi->num_progs++;
2542 		debug_printf("done_command: num_progs incremented to %d\n",pi->num_progs);
2543 	} else {
2544 		debug_printf("done_command: initializing\n");
2545 	}
2546 	pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
2547 
2548 	prog = pi->progs + pi->num_progs;
2549 #ifndef __U_BOOT__
2550 	prog->redirects = NULL;
2551 #endif
2552 	prog->argv = NULL;
2553 	prog->argv_nonnull = NULL;
2554 #ifndef __U_BOOT__
2555 	prog->is_stopped = 0;
2556 #endif
2557 	prog->group = NULL;
2558 #ifndef __U_BOOT__
2559 	prog->glob_result.gl_pathv = NULL;
2560 	prog->family = pi;
2561 #endif
2562 	prog->sp = 0;
2563 	ctx->child = prog;
2564 	prog->type = ctx->type;
2565 
2566 	/* but ctx->pipe and ctx->list_head remain unchanged */
2567 	return 0;
2568 }
2569 
2570 static int done_pipe(struct p_context *ctx, pipe_style type)
2571 {
2572 	struct pipe *new_p;
2573 	done_command(ctx);  /* implicit closure of previous command */
2574 	debug_printf("done_pipe, type %d\n", type);
2575 	ctx->pipe->followup = type;
2576 	ctx->pipe->r_mode = ctx->w;
2577 	new_p=new_pipe();
2578 	ctx->pipe->next = new_p;
2579 	ctx->pipe = new_p;
2580 	ctx->child = NULL;
2581 	done_command(ctx);  /* set up new pipe to accept commands */
2582 	return 0;
2583 }
2584 
2585 #ifndef __U_BOOT__
2586 /* peek ahead in the in_str to find out if we have a "&n" construct,
2587  * as in "2>&1", that represents duplicating a file descriptor.
2588  * returns either -2 (syntax error), -1 (no &), or the number found.
2589  */
2590 static int redirect_dup_num(struct in_str *input)
2591 {
2592 	int ch, d=0, ok=0;
2593 	ch = b_peek(input);
2594 	if (ch != '&') return -1;
2595 
2596 	b_getch(input);  /* get the & */
2597 	ch=b_peek(input);
2598 	if (ch == '-') {
2599 		b_getch(input);
2600 		return -3;  /* "-" represents "close me" */
2601 	}
2602 	while (isdigit(ch)) {
2603 		d = d*10+(ch-'0');
2604 		ok=1;
2605 		b_getch(input);
2606 		ch = b_peek(input);
2607 	}
2608 	if (ok) return d;
2609 
2610 	error_msg("ambiguous redirect");
2611 	return -2;
2612 }
2613 
2614 /* If a redirect is immediately preceded by a number, that number is
2615  * supposed to tell which file descriptor to redirect.  This routine
2616  * looks for such preceding numbers.  In an ideal world this routine
2617  * needs to handle all the following classes of redirects...
2618  *     echo 2>foo     # redirects fd  2 to file "foo", nothing passed to echo
2619  *     echo 49>foo    # redirects fd 49 to file "foo", nothing passed to echo
2620  *     echo -2>foo    # redirects fd  1 to file "foo",    "-2" passed to echo
2621  *     echo 49x>foo   # redirects fd  1 to file "foo",   "49x" passed to echo
2622  * A -1 output from this program means no valid number was found, so the
2623  * caller should use the appropriate default for this redirection.
2624  */
2625 static int redirect_opt_num(o_string *o)
2626 {
2627 	int num;
2628 
2629 	if (o->length==0) return -1;
2630 	for(num=0; num<o->length; num++) {
2631 		if (!isdigit(*(o->data+num))) {
2632 			return -1;
2633 		}
2634 	}
2635 	/* reuse num (and save an int) */
2636 	num=atoi(o->data);
2637 	b_reset(o);
2638 	return num;
2639 }
2640 
2641 FILE *generate_stream_from_list(struct pipe *head)
2642 {
2643 	FILE *pf;
2644 #if 1
2645 	int pid, channel[2];
2646 	if (pipe(channel)<0) perror_msg_and_die("pipe");
2647 	pid=fork();
2648 	if (pid<0) {
2649 		perror_msg_and_die("fork");
2650 	} else if (pid==0) {
2651 		close(channel[0]);
2652 		if (channel[1] != 1) {
2653 			dup2(channel[1],1);
2654 			close(channel[1]);
2655 		}
2656 #if 0
2657 #define SURROGATE "surrogate response"
2658 		write(1,SURROGATE,sizeof(SURROGATE));
2659 		_exit(run_list(head));
2660 #else
2661 		_exit(run_list_real(head));   /* leaks memory */
2662 #endif
2663 	}
2664 	debug_printf("forked child %d\n",pid);
2665 	close(channel[1]);
2666 	pf = fdopen(channel[0],"r");
2667 	debug_printf("pipe on FILE *%p\n",pf);
2668 #else
2669 	free_pipe_list(head,0);
2670 	pf=popen("echo surrogate response","r");
2671 	debug_printf("started fake pipe on FILE *%p\n",pf);
2672 #endif
2673 	return pf;
2674 }
2675 
2676 /* this version hacked for testing purposes */
2677 /* return code is exit status of the process that is run. */
2678 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end)
2679 {
2680 	int retcode;
2681 	o_string result=NULL_O_STRING;
2682 	struct p_context inner;
2683 	FILE *p;
2684 	struct in_str pipe_str;
2685 	initialize_context(&inner);
2686 
2687 	/* recursion to generate command */
2688 	retcode = parse_stream(&result, &inner, input, subst_end);
2689 	if (retcode != 0) return retcode;  /* syntax error or EOF */
2690 	done_word(&result, &inner);
2691 	done_pipe(&inner, PIPE_SEQ);
2692 	b_free(&result);
2693 
2694 	p=generate_stream_from_list(inner.list_head);
2695 	if (p==NULL) return 1;
2696 	mark_open(fileno(p));
2697 	setup_file_in_str(&pipe_str, p);
2698 
2699 	/* now send results of command back into original context */
2700 	retcode = parse_stream(dest, ctx, &pipe_str, '\0');
2701 	/* XXX In case of a syntax error, should we try to kill the child?
2702 	 * That would be tough to do right, so just read until EOF. */
2703 	if (retcode == 1) {
2704 		while (b_getch(&pipe_str)!=EOF) { /* discard */ };
2705 	}
2706 
2707 	debug_printf("done reading from pipe, pclose()ing\n");
2708 	/* This is the step that wait()s for the child.  Should be pretty
2709 	 * safe, since we just read an EOF from its stdout.  We could try
2710 	 * to better, by using wait(), and keeping track of background jobs
2711 	 * at the same time.  That would be a lot of work, and contrary
2712 	 * to the KISS philosophy of this program. */
2713 	mark_closed(fileno(p));
2714 	retcode=pclose(p);
2715 	free_pipe_list(inner.list_head,0);
2716 	debug_printf("pclosed, retcode=%d\n",retcode);
2717 	/* XXX this process fails to trim a single trailing newline */
2718 	return retcode;
2719 }
2720 
2721 static int parse_group(o_string *dest, struct p_context *ctx,
2722 	struct in_str *input, int ch)
2723 {
2724 	int rcode, endch=0;
2725 	struct p_context sub;
2726 	struct child_prog *child = ctx->child;
2727 	if (child->argv) {
2728 		syntax();
2729 		return 1;  /* syntax error, groups and arglists don't mix */
2730 	}
2731 	initialize_context(&sub);
2732 	switch(ch) {
2733 		case '(': endch=')'; child->subshell=1; break;
2734 		case '{': endch='}'; break;
2735 		default: syntax();   /* really logic error */
2736 	}
2737 	rcode=parse_stream(dest,&sub,input,endch);
2738 	done_word(dest,&sub); /* finish off the final word in the subcontext */
2739 	done_pipe(&sub, PIPE_SEQ);  /* and the final command there, too */
2740 	child->group = sub.list_head;
2741 	return rcode;
2742 	/* child remains "open", available for possible redirects */
2743 }
2744 #endif
2745 
2746 /* basically useful version until someone wants to get fancier,
2747  * see the bash man page under "Parameter Expansion" */
2748 static char *lookup_param(char *src)
2749 {
2750 	char *p;
2751 	char *sep;
2752 	char *default_val = NULL;
2753 	int assign = 0;
2754 	int expand_empty = 0;
2755 
2756 	if (!src)
2757 		return NULL;
2758 
2759 	sep = strchr(src, ':');
2760 
2761 	if (sep) {
2762 		*sep = '\0';
2763 		if (*(sep + 1) == '-')
2764 			default_val = sep+2;
2765 		if (*(sep + 1) == '=') {
2766 			default_val = sep+2;
2767 			assign = 1;
2768 		}
2769 		if (*(sep + 1) == '+') {
2770 			default_val = sep+2;
2771 			expand_empty = 1;
2772 		}
2773 	}
2774 
2775 	p = getenv(src);
2776 	if (!p)
2777 		p = get_local_var(src);
2778 
2779 	if (!p || strlen(p) == 0) {
2780 		p = default_val;
2781 		if (assign) {
2782 			char *var = malloc(strlen(src)+strlen(default_val)+2);
2783 			if (var) {
2784 				sprintf(var, "%s=%s", src, default_val);
2785 				set_local_var(var, 0);
2786 			}
2787 			free(var);
2788 		}
2789 	} else if (expand_empty) {
2790 		p += strlen(p);
2791 	}
2792 
2793 	if (sep)
2794 		*sep = ':';
2795 
2796 	return p;
2797 }
2798 
2799 #ifdef __U_BOOT__
2800 static char *get_dollar_var(char ch)
2801 {
2802 	static char buf[40];
2803 
2804 	buf[0] = '\0';
2805 	switch (ch) {
2806 		case '?':
2807 			sprintf(buf, "%u", (unsigned int)last_return_code);
2808 			break;
2809 		default:
2810 			return NULL;
2811 	}
2812 	return buf;
2813 }
2814 #endif
2815 
2816 /* return code: 0 for OK, 1 for syntax error */
2817 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input)
2818 {
2819 #ifndef __U_BOOT__
2820 	int i, advance=0;
2821 #else
2822 	int advance=0;
2823 #endif
2824 #ifndef __U_BOOT__
2825 	char sep[]=" ";
2826 #endif
2827 	int ch = input->peek(input);  /* first character after the $ */
2828 	debug_printf("handle_dollar: ch=%c\n",ch);
2829 	if (isalpha(ch)) {
2830 		b_addchr(dest, SPECIAL_VAR_SYMBOL);
2831 		ctx->child->sp++;
2832 		while(ch=b_peek(input),isalnum(ch) || ch=='_') {
2833 			b_getch(input);
2834 			b_addchr(dest,ch);
2835 		}
2836 		b_addchr(dest, SPECIAL_VAR_SYMBOL);
2837 #ifndef __U_BOOT__
2838 	} else if (isdigit(ch)) {
2839 		i = ch-'0';  /* XXX is $0 special? */
2840 		if (i<global_argc) {
2841 			parse_string(dest, ctx, global_argv[i]); /* recursion */
2842 		}
2843 		advance = 1;
2844 #endif
2845 	} else switch (ch) {
2846 #ifndef __U_BOOT__
2847 		case '$':
2848 			b_adduint(dest,getpid());
2849 			advance = 1;
2850 			break;
2851 		case '!':
2852 			if (last_bg_pid > 0) b_adduint(dest, last_bg_pid);
2853 			advance = 1;
2854 			break;
2855 #endif
2856 		case '?':
2857 #ifndef __U_BOOT__
2858 			b_adduint(dest,last_return_code);
2859 #else
2860 			ctx->child->sp++;
2861 			b_addchr(dest, SPECIAL_VAR_SYMBOL);
2862 			b_addchr(dest, '$');
2863 			b_addchr(dest, '?');
2864 			b_addchr(dest, SPECIAL_VAR_SYMBOL);
2865 #endif
2866 			advance = 1;
2867 			break;
2868 #ifndef __U_BOOT__
2869 		case '#':
2870 			b_adduint(dest,global_argc ? global_argc-1 : 0);
2871 			advance = 1;
2872 			break;
2873 #endif
2874 		case '{':
2875 			b_addchr(dest, SPECIAL_VAR_SYMBOL);
2876 			ctx->child->sp++;
2877 			b_getch(input);
2878 			/* XXX maybe someone will try to escape the '}' */
2879 			while(ch=b_getch(input),ch!=EOF && ch!='}') {
2880 				b_addchr(dest,ch);
2881 			}
2882 			if (ch != '}') {
2883 				syntax();
2884 				return 1;
2885 			}
2886 			b_addchr(dest, SPECIAL_VAR_SYMBOL);
2887 			break;
2888 #ifndef __U_BOOT__
2889 		case '(':
2890 			b_getch(input);
2891 			process_command_subs(dest, ctx, input, ')');
2892 			break;
2893 		case '*':
2894 			sep[0]=ifs[0];
2895 			for (i=1; i<global_argc; i++) {
2896 				parse_string(dest, ctx, global_argv[i]);
2897 				if (i+1 < global_argc) parse_string(dest, ctx, sep);
2898 			}
2899 			break;
2900 		case '@':
2901 		case '-':
2902 		case '_':
2903 			/* still unhandled, but should be eventually */
2904 			error_msg("unhandled syntax: $%c",ch);
2905 			return 1;
2906 			break;
2907 #endif
2908 		default:
2909 			b_addqchr(dest,'$',dest->quote);
2910 	}
2911 	/* Eat the character if the flag was set.  If the compiler
2912 	 * is smart enough, we could substitute "b_getch(input);"
2913 	 * for all the "advance = 1;" above, and also end up with
2914 	 * a nice size-optimized program.  Hah!  That'll be the day.
2915 	 */
2916 	if (advance) b_getch(input);
2917 	return 0;
2918 }
2919 
2920 #ifndef __U_BOOT__
2921 int parse_string(o_string *dest, struct p_context *ctx, const char *src)
2922 {
2923 	struct in_str foo;
2924 	setup_string_in_str(&foo, src);
2925 	return parse_stream(dest, ctx, &foo, '\0');
2926 }
2927 #endif
2928 
2929 /* return code is 0 for normal exit, 1 for syntax error */
2930 static int parse_stream(o_string *dest, struct p_context *ctx,
2931 			struct in_str *input, int end_trigger)
2932 {
2933 	unsigned int ch, m;
2934 #ifndef __U_BOOT__
2935 	int redir_fd;
2936 	redir_type redir_style;
2937 #endif
2938 	int next;
2939 
2940 	/* Only double-quote state is handled in the state variable dest->quote.
2941 	 * A single-quote triggers a bypass of the main loop until its mate is
2942 	 * found.  When recursing, quote state is passed in via dest->quote. */
2943 
2944 	debug_printf("parse_stream, end_trigger=%d\n",end_trigger);
2945 	while ((ch=b_getch(input))!=EOF) {
2946 		m = map[ch];
2947 #ifdef __U_BOOT__
2948 		if (input->__promptme == 0) return 1;
2949 #endif
2950 		next = (ch == '\n') ? 0 : b_peek(input);
2951 
2952 		debug_printf("parse_stream: ch=%c (%d) m=%d quote=%d - %c\n",
2953 			ch >= ' ' ? ch : '.', ch, m,
2954 			dest->quote, ctx->stack == NULL ? '*' : '.');
2955 
2956 		if (m==0 || ((m==1 || m==2) && dest->quote)) {
2957 			b_addqchr(dest, ch, dest->quote);
2958 		} else {
2959 			if (m==2) {  /* unquoted IFS */
2960 				if (done_word(dest, ctx)) {
2961 					return 1;
2962 				}
2963 				/* If we aren't performing a substitution, treat a newline as a
2964 				 * command separator.  */
2965 				if (end_trigger != '\0' && ch=='\n')
2966 					done_pipe(ctx,PIPE_SEQ);
2967 			}
2968 			if (ch == end_trigger && !dest->quote && ctx->w==RES_NONE) {
2969 				debug_printf("leaving parse_stream (triggered)\n");
2970 				return 0;
2971 			}
2972 #if 0
2973 			if (ch=='\n') {
2974 				/* Yahoo!  Time to run with it! */
2975 				done_pipe(ctx,PIPE_SEQ);
2976 				run_list(ctx->list_head);
2977 				initialize_context(ctx);
2978 			}
2979 #endif
2980 			if (m!=2) switch (ch) {
2981 		case '#':
2982 			if (dest->length == 0 && !dest->quote) {
2983 				while(ch=b_peek(input),ch!=EOF && ch!='\n') { b_getch(input); }
2984 			} else {
2985 				b_addqchr(dest, ch, dest->quote);
2986 			}
2987 			break;
2988 		case '\\':
2989 			if (next == EOF) {
2990 				syntax();
2991 				return 1;
2992 			}
2993 			b_addqchr(dest, '\\', dest->quote);
2994 			b_addqchr(dest, b_getch(input), dest->quote);
2995 			break;
2996 		case '$':
2997 			if (handle_dollar(dest, ctx, input)!=0) return 1;
2998 			break;
2999 		case '\'':
3000 			dest->nonnull = 1;
3001 			while(ch=b_getch(input),ch!=EOF && ch!='\'') {
3002 #ifdef __U_BOOT__
3003 				if(input->__promptme == 0) return 1;
3004 #endif
3005 				b_addchr(dest,ch);
3006 			}
3007 			if (ch==EOF) {
3008 				syntax();
3009 				return 1;
3010 			}
3011 			break;
3012 		case '"':
3013 			dest->nonnull = 1;
3014 			dest->quote = !dest->quote;
3015 			break;
3016 #ifndef __U_BOOT__
3017 		case '`':
3018 			process_command_subs(dest, ctx, input, '`');
3019 			break;
3020 		case '>':
3021 			redir_fd = redirect_opt_num(dest);
3022 			done_word(dest, ctx);
3023 			redir_style=REDIRECT_OVERWRITE;
3024 			if (next == '>') {
3025 				redir_style=REDIRECT_APPEND;
3026 				b_getch(input);
3027 			} else if (next == '(') {
3028 				syntax();   /* until we support >(list) Process Substitution */
3029 				return 1;
3030 			}
3031 			setup_redirect(ctx, redir_fd, redir_style, input);
3032 			break;
3033 		case '<':
3034 			redir_fd = redirect_opt_num(dest);
3035 			done_word(dest, ctx);
3036 			redir_style=REDIRECT_INPUT;
3037 			if (next == '<') {
3038 				redir_style=REDIRECT_HEREIS;
3039 				b_getch(input);
3040 			} else if (next == '>') {
3041 				redir_style=REDIRECT_IO;
3042 				b_getch(input);
3043 			} else if (next == '(') {
3044 				syntax();   /* until we support <(list) Process Substitution */
3045 				return 1;
3046 			}
3047 			setup_redirect(ctx, redir_fd, redir_style, input);
3048 			break;
3049 #endif
3050 		case ';':
3051 			done_word(dest, ctx);
3052 			done_pipe(ctx,PIPE_SEQ);
3053 			break;
3054 		case '&':
3055 			done_word(dest, ctx);
3056 			if (next=='&') {
3057 				b_getch(input);
3058 				done_pipe(ctx,PIPE_AND);
3059 			} else {
3060 #ifndef __U_BOOT__
3061 				done_pipe(ctx,PIPE_BG);
3062 #else
3063 				syntax_err();
3064 				return 1;
3065 #endif
3066 			}
3067 			break;
3068 		case '|':
3069 			done_word(dest, ctx);
3070 			if (next=='|') {
3071 				b_getch(input);
3072 				done_pipe(ctx,PIPE_OR);
3073 			} else {
3074 				/* we could pick up a file descriptor choice here
3075 				 * with redirect_opt_num(), but bash doesn't do it.
3076 				 * "echo foo 2| cat" yields "foo 2". */
3077 #ifndef __U_BOOT__
3078 				done_command(ctx);
3079 #else
3080 				syntax_err();
3081 				return 1;
3082 #endif
3083 			}
3084 			break;
3085 #ifndef __U_BOOT__
3086 		case '(':
3087 		case '{':
3088 			if (parse_group(dest, ctx, input, ch)!=0) return 1;
3089 			break;
3090 		case ')':
3091 		case '}':
3092 			syntax();   /* Proper use of this character caught by end_trigger */
3093 			return 1;
3094 			break;
3095 #endif
3096 		case SUBSTED_VAR_SYMBOL:
3097 			dest->nonnull = 1;
3098 			while (ch = b_getch(input), ch != EOF &&
3099 			    ch != SUBSTED_VAR_SYMBOL) {
3100 				debug_printf("subst, pass=%d\n", ch);
3101 				if (input->__promptme == 0)
3102 					return 1;
3103 				b_addchr(dest, ch);
3104 			}
3105 			debug_printf("subst, term=%d\n", ch);
3106 			if (ch == EOF) {
3107 				syntax();
3108 				return 1;
3109 			}
3110 			break;
3111 		default:
3112 			syntax();   /* this is really an internal logic error */
3113 			return 1;
3114 			}
3115 		}
3116 	}
3117 	/* complain if quote?  No, maybe we just finished a command substitution
3118 	 * that was quoted.  Example:
3119 	 * $ echo "`cat foo` plus more"
3120 	 * and we just got the EOF generated by the subshell that ran "cat foo"
3121 	 * The only real complaint is if we got an EOF when end_trigger != '\0',
3122 	 * that is, we were really supposed to get end_trigger, and never got
3123 	 * one before the EOF.  Can't use the standard "syntax error" return code,
3124 	 * so that parse_stream_outer can distinguish the EOF and exit smoothly. */
3125 	debug_printf("leaving parse_stream (EOF)\n");
3126 	if (end_trigger != '\0') return -1;
3127 	return 0;
3128 }
3129 
3130 static void mapset(const unsigned char *set, int code)
3131 {
3132 	const unsigned char *s;
3133 	for (s=set; *s; s++) map[*s] = code;
3134 }
3135 
3136 static void update_ifs_map(void)
3137 {
3138 	/* char *ifs and char map[256] are both globals. */
3139 	ifs = (uchar *)getenv("IFS");
3140 	if (ifs == NULL) ifs=(uchar *)" \t\n";
3141 	/* Precompute a list of 'flow through' behavior so it can be treated
3142 	 * quickly up front.  Computation is necessary because of IFS.
3143 	 * Special case handling of IFS == " \t\n" is not implemented.
3144 	 * The map[] array only really needs two bits each, and on most machines
3145 	 * that would be faster because of the reduced L1 cache footprint.
3146 	 */
3147 	memset(map,0,sizeof(map)); /* most characters flow through always */
3148 #ifndef __U_BOOT__
3149 	mapset((uchar *)"\\$'\"`", 3);      /* never flow through */
3150 	mapset((uchar *)"<>;&|(){}#", 1);   /* flow through if quoted */
3151 #else
3152 	{
3153 		uchar subst[2] = {SUBSTED_VAR_SYMBOL, 0};
3154 		mapset(subst, 3);       /* never flow through */
3155 	}
3156 	mapset((uchar *)"\\$'\"", 3);       /* never flow through */
3157 	mapset((uchar *)";&|#", 1);         /* flow through if quoted */
3158 #endif
3159 	mapset(ifs, 2);            /* also flow through if quoted */
3160 }
3161 
3162 /* most recursion does not come through here, the exeception is
3163  * from builtin_source() */
3164 static int parse_stream_outer(struct in_str *inp, int flag)
3165 {
3166 
3167 	struct p_context ctx;
3168 	o_string temp=NULL_O_STRING;
3169 	int rcode;
3170 #ifdef __U_BOOT__
3171 	int code = 1;
3172 #endif
3173 	do {
3174 		ctx.type = flag;
3175 		initialize_context(&ctx);
3176 		update_ifs_map();
3177 		if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING)) mapset((uchar *)";$&|", 0);
3178 		inp->promptmode=1;
3179 		rcode = parse_stream(&temp, &ctx, inp,
3180 				     flag & FLAG_CONT_ON_NEWLINE ? -1 : '\n');
3181 #ifdef __U_BOOT__
3182 		if (rcode == 1) flag_repeat = 0;
3183 #endif
3184 		if (rcode != 1 && ctx.old_flag != 0) {
3185 			syntax();
3186 #ifdef __U_BOOT__
3187 			flag_repeat = 0;
3188 #endif
3189 		}
3190 		if (rcode != 1 && ctx.old_flag == 0) {
3191 			done_word(&temp, &ctx);
3192 			done_pipe(&ctx,PIPE_SEQ);
3193 #ifndef __U_BOOT__
3194 			run_list(ctx.list_head);
3195 #else
3196 			code = run_list(ctx.list_head);
3197 			if (code == -2) {	/* exit */
3198 				b_free(&temp);
3199 				code = 0;
3200 				/* XXX hackish way to not allow exit from main loop */
3201 				if (inp->peek == file_peek) {
3202 					printf("exit not allowed from main input shell.\n");
3203 					continue;
3204 				}
3205 				break;
3206 			}
3207 			if (code == -1)
3208 			    flag_repeat = 0;
3209 #endif
3210 		} else {
3211 			if (ctx.old_flag != 0) {
3212 				free(ctx.stack);
3213 				b_reset(&temp);
3214 			}
3215 #ifdef __U_BOOT__
3216 			if (inp->__promptme == 0) printf("<INTERRUPT>\n");
3217 			inp->__promptme = 1;
3218 #endif
3219 			temp.nonnull = 0;
3220 			temp.quote = 0;
3221 			inp->p = NULL;
3222 			free_pipe_list(ctx.list_head,0);
3223 		}
3224 		b_free(&temp);
3225 	/* loop on syntax errors, return on EOF */
3226 	} while (rcode != -1 && !(flag & FLAG_EXIT_FROM_LOOP) &&
3227 		(inp->peek != static_peek || b_peek(inp)));
3228 #ifndef __U_BOOT__
3229 	return 0;
3230 #else
3231 	return (code != 0) ? 1 : 0;
3232 #endif /* __U_BOOT__ */
3233 }
3234 
3235 #ifndef __U_BOOT__
3236 static int parse_string_outer(const char *s, int flag)
3237 #else
3238 int parse_string_outer(const char *s, int flag)
3239 #endif	/* __U_BOOT__ */
3240 {
3241 	struct in_str input;
3242 #ifdef __U_BOOT__
3243 	char *p = NULL;
3244 	int rcode;
3245 	if (!s)
3246 		return 1;
3247 	if (!*s)
3248 		return 0;
3249 	if (!(p = strchr(s, '\n')) || *++p) {
3250 		p = xmalloc(strlen(s) + 2);
3251 		strcpy(p, s);
3252 		strcat(p, "\n");
3253 		setup_string_in_str(&input, p);
3254 		rcode = parse_stream_outer(&input, flag);
3255 		free(p);
3256 		return rcode;
3257 	} else {
3258 #endif
3259 	setup_string_in_str(&input, s);
3260 	return parse_stream_outer(&input, flag);
3261 #ifdef __U_BOOT__
3262 	}
3263 #endif
3264 }
3265 
3266 #ifndef __U_BOOT__
3267 static int parse_file_outer(FILE *f)
3268 #else
3269 int parse_file_outer(void)
3270 #endif
3271 {
3272 	int rcode;
3273 	struct in_str input;
3274 #ifndef __U_BOOT__
3275 	setup_file_in_str(&input, f);
3276 #else
3277 	setup_file_in_str(&input);
3278 #endif
3279 	rcode = parse_stream_outer(&input, FLAG_PARSE_SEMICOLON);
3280 	return rcode;
3281 }
3282 
3283 #ifdef __U_BOOT__
3284 #ifdef CONFIG_NEEDS_MANUAL_RELOC
3285 static void u_boot_hush_reloc(void)
3286 {
3287 	unsigned long addr;
3288 	struct reserved_combo *r;
3289 
3290 	for (r=reserved_list; r<reserved_list+NRES; r++) {
3291 		addr = (ulong) (r->literal) + gd->reloc_off;
3292 		r->literal = (char *)addr;
3293 	}
3294 }
3295 #endif
3296 
3297 int u_boot_hush_start(void)
3298 {
3299 	if (top_vars == NULL) {
3300 		top_vars = malloc(sizeof(struct variables));
3301 		top_vars->name = "HUSH_VERSION";
3302 		top_vars->value = "0.01";
3303 		top_vars->next = NULL;
3304 		top_vars->flg_export = 0;
3305 		top_vars->flg_read_only = 1;
3306 #ifdef CONFIG_NEEDS_MANUAL_RELOC
3307 		u_boot_hush_reloc();
3308 #endif
3309 	}
3310 	return 0;
3311 }
3312 
3313 static void *xmalloc(size_t size)
3314 {
3315 	void *p = NULL;
3316 
3317 	if (!(p = malloc(size))) {
3318 	    printf("ERROR : memory not allocated\n");
3319 	    for(;;);
3320 	}
3321 	return p;
3322 }
3323 
3324 static void *xrealloc(void *ptr, size_t size)
3325 {
3326 	void *p = NULL;
3327 
3328 	if (!(p = realloc(ptr, size))) {
3329 	    printf("ERROR : memory not allocated\n");
3330 	    for(;;);
3331 	}
3332 	return p;
3333 }
3334 #endif /* __U_BOOT__ */
3335 
3336 #ifndef __U_BOOT__
3337 /* Make sure we have a controlling tty.  If we get started under a job
3338  * aware app (like bash for example), make sure we are now in charge so
3339  * we don't fight over who gets the foreground */
3340 static void setup_job_control(void)
3341 {
3342 	static pid_t shell_pgrp;
3343 	/* Loop until we are in the foreground.  */
3344 	while (tcgetpgrp (shell_terminal) != (shell_pgrp = getpgrp ()))
3345 		kill (- shell_pgrp, SIGTTIN);
3346 
3347 	/* Ignore interactive and job-control signals.  */
3348 	signal(SIGINT, SIG_IGN);
3349 	signal(SIGQUIT, SIG_IGN);
3350 	signal(SIGTERM, SIG_IGN);
3351 	signal(SIGTSTP, SIG_IGN);
3352 	signal(SIGTTIN, SIG_IGN);
3353 	signal(SIGTTOU, SIG_IGN);
3354 	signal(SIGCHLD, SIG_IGN);
3355 
3356 	/* Put ourselves in our own process group.  */
3357 	setsid();
3358 	shell_pgrp = getpid ();
3359 	setpgid (shell_pgrp, shell_pgrp);
3360 
3361 	/* Grab control of the terminal.  */
3362 	tcsetpgrp(shell_terminal, shell_pgrp);
3363 }
3364 
3365 int hush_main(int argc, char * const *argv)
3366 {
3367 	int opt;
3368 	FILE *input;
3369 	char **e = environ;
3370 
3371 	/* XXX what should these be while sourcing /etc/profile? */
3372 	global_argc = argc;
3373 	global_argv = argv;
3374 
3375 	/* (re?) initialize globals.  Sometimes hush_main() ends up calling
3376 	 * hush_main(), therefore we cannot rely on the BSS to zero out this
3377 	 * stuff.  Reset these to 0 every time. */
3378 	ifs = NULL;
3379 	/* map[] is taken care of with call to update_ifs_map() */
3380 	fake_mode = 0;
3381 	interactive = 0;
3382 	close_me_head = NULL;
3383 	last_bg_pid = 0;
3384 	job_list = NULL;
3385 	last_jobid = 0;
3386 
3387 	/* Initialize some more globals to non-zero values */
3388 	set_cwd();
3389 #ifdef CONFIG_FEATURE_COMMAND_EDITING
3390 	cmdedit_set_initial_prompt();
3391 #else
3392 	PS1 = NULL;
3393 #endif
3394 	PS2 = "> ";
3395 
3396 	/* initialize our shell local variables with the values
3397 	 * currently living in the environment */
3398 	if (e) {
3399 		for (; *e; e++)
3400 			set_local_var(*e, 2);   /* without call putenv() */
3401 	}
3402 
3403 	last_return_code=EXIT_SUCCESS;
3404 
3405 
3406 	if (argv[0] && argv[0][0] == '-') {
3407 		debug_printf("\nsourcing /etc/profile\n");
3408 		if ((input = fopen("/etc/profile", "r")) != NULL) {
3409 			mark_open(fileno(input));
3410 			parse_file_outer(input);
3411 			mark_closed(fileno(input));
3412 			fclose(input);
3413 		}
3414 	}
3415 	input=stdin;
3416 
3417 	while ((opt = getopt(argc, argv, "c:xif")) > 0) {
3418 		switch (opt) {
3419 			case 'c':
3420 				{
3421 					global_argv = argv+optind;
3422 					global_argc = argc-optind;
3423 					opt = parse_string_outer(optarg, FLAG_PARSE_SEMICOLON);
3424 					goto final_return;
3425 				}
3426 				break;
3427 			case 'i':
3428 				interactive++;
3429 				break;
3430 			case 'f':
3431 				fake_mode++;
3432 				break;
3433 			default:
3434 #ifndef BB_VER
3435 				fprintf(stderr, "Usage: sh [FILE]...\n"
3436 						"   or: sh -c command [args]...\n\n");
3437 				exit(EXIT_FAILURE);
3438 #else
3439 				show_usage();
3440 #endif
3441 		}
3442 	}
3443 	/* A shell is interactive if the `-i' flag was given, or if all of
3444 	 * the following conditions are met:
3445 	 *	  no -c command
3446 	 *    no arguments remaining or the -s flag given
3447 	 *    standard input is a terminal
3448 	 *    standard output is a terminal
3449 	 *    Refer to Posix.2, the description of the `sh' utility. */
3450 	if (argv[optind]==NULL && input==stdin &&
3451 			isatty(fileno(stdin)) && isatty(fileno(stdout))) {
3452 		interactive++;
3453 	}
3454 
3455 	debug_printf("\ninteractive=%d\n", interactive);
3456 	if (interactive) {
3457 		/* Looks like they want an interactive shell */
3458 #ifndef CONFIG_FEATURE_SH_EXTRA_QUIET
3459 		printf( "\n\n" BB_BANNER " hush - the humble shell v0.01 (testing)\n");
3460 		printf( "Enter 'help' for a list of built-in commands.\n\n");
3461 #endif
3462 		setup_job_control();
3463 	}
3464 
3465 	if (argv[optind]==NULL) {
3466 		opt=parse_file_outer(stdin);
3467 		goto final_return;
3468 	}
3469 
3470 	debug_printf("\nrunning script '%s'\n", argv[optind]);
3471 	global_argv = argv+optind;
3472 	global_argc = argc-optind;
3473 	input = xfopen(argv[optind], "r");
3474 	opt = parse_file_outer(input);
3475 
3476 #ifdef CONFIG_FEATURE_CLEAN_UP
3477 	fclose(input);
3478 	if (cwd && cwd != unknown)
3479 		free((char*)cwd);
3480 	{
3481 		struct variables *cur, *tmp;
3482 		for(cur = top_vars; cur; cur = tmp) {
3483 			tmp = cur->next;
3484 			if (!cur->flg_read_only) {
3485 				free(cur->name);
3486 				free(cur->value);
3487 				free(cur);
3488 			}
3489 		}
3490 	}
3491 #endif
3492 
3493 final_return:
3494 	return(opt?opt:last_return_code);
3495 }
3496 #endif
3497 
3498 static char *insert_var_value(char *inp)
3499 {
3500 	return insert_var_value_sub(inp, 0);
3501 }
3502 
3503 static char *insert_var_value_sub(char *inp, int tag_subst)
3504 {
3505 	int res_str_len = 0;
3506 	int len;
3507 	int done = 0;
3508 	char *p, *p1, *res_str = NULL;
3509 
3510 	while ((p = strchr(inp, SPECIAL_VAR_SYMBOL))) {
3511 		/* check the beginning of the string for normal characters */
3512 		if (p != inp) {
3513 			/* copy any characters to the result string */
3514 			len = p - inp;
3515 			res_str = xrealloc(res_str, (res_str_len + len));
3516 			strncpy((res_str + res_str_len), inp, len);
3517 			res_str_len += len;
3518 		}
3519 		inp = ++p;
3520 		/* find the ending marker */
3521 		p = strchr(inp, SPECIAL_VAR_SYMBOL);
3522 		*p = '\0';
3523 		/* look up the value to substitute */
3524 		if ((p1 = lookup_param(inp))) {
3525 			if (tag_subst)
3526 				len = res_str_len + strlen(p1) + 2;
3527 			else
3528 				len = res_str_len + strlen(p1);
3529 			res_str = xrealloc(res_str, (1 + len));
3530 			if (tag_subst) {
3531 				/*
3532 				 * copy the variable value to the result
3533 				 * string
3534 				 */
3535 				strcpy((res_str + res_str_len + 1), p1);
3536 
3537 				/*
3538 				 * mark the replaced text to be accepted as
3539 				 * is
3540 				 */
3541 				res_str[res_str_len] = SUBSTED_VAR_SYMBOL;
3542 				res_str[res_str_len + 1 + strlen(p1)] =
3543 					SUBSTED_VAR_SYMBOL;
3544 			} else
3545 				/*
3546 				 * copy the variable value to the result
3547 				 * string
3548 				 */
3549 				strcpy((res_str + res_str_len), p1);
3550 
3551 			res_str_len = len;
3552 		}
3553 		*p = SPECIAL_VAR_SYMBOL;
3554 		inp = ++p;
3555 		done = 1;
3556 	}
3557 	if (done) {
3558 		res_str = xrealloc(res_str, (1 + res_str_len + strlen(inp)));
3559 		strcpy((res_str + res_str_len), inp);
3560 		while ((p = strchr(res_str, '\n'))) {
3561 			*p = ' ';
3562 		}
3563 	}
3564 	return (res_str == NULL) ? inp : res_str;
3565 }
3566 
3567 static char **make_list_in(char **inp, char *name)
3568 {
3569 	int len, i;
3570 	int name_len = strlen(name);
3571 	int n = 0;
3572 	char **list;
3573 	char *p1, *p2, *p3;
3574 
3575 	/* create list of variable values */
3576 	list = xmalloc(sizeof(*list));
3577 	for (i = 0; inp[i]; i++) {
3578 		p3 = insert_var_value(inp[i]);
3579 		p1 = p3;
3580 		while (*p1) {
3581 			if (*p1 == ' ') {
3582 				p1++;
3583 				continue;
3584 			}
3585 			if ((p2 = strchr(p1, ' '))) {
3586 				len = p2 - p1;
3587 			} else {
3588 				len = strlen(p1);
3589 				p2 = p1 + len;
3590 			}
3591 			/* we use n + 2 in realloc for list,because we add
3592 			 * new element and then we will add NULL element */
3593 			list = xrealloc(list, sizeof(*list) * (n + 2));
3594 			list[n] = xmalloc(2 + name_len + len);
3595 			strcpy(list[n], name);
3596 			strcat(list[n], "=");
3597 			strncat(list[n], p1, len);
3598 			list[n++][name_len + len + 1] = '\0';
3599 			p1 = p2;
3600 		}
3601 		if (p3 != inp[i]) free(p3);
3602 	}
3603 	list[n] = NULL;
3604 	return list;
3605 }
3606 
3607 /*
3608  * Make new string for parser
3609  * inp     - array of argument strings to flatten
3610  * nonnull - indicates argument was quoted when originally parsed
3611  */
3612 static char *make_string(char **inp, int *nonnull)
3613 {
3614 	char *p;
3615 	char *str = NULL;
3616 	int n;
3617 	int len = 2;
3618 	char *noeval_str;
3619 	int noeval = 0;
3620 
3621 	noeval_str = get_local_var("HUSH_NO_EVAL");
3622 	if (noeval_str != NULL && *noeval_str != '0' && *noeval_str != '\0')
3623 		noeval = 1;
3624 	for (n = 0; inp[n]; n++) {
3625 		p = insert_var_value_sub(inp[n], noeval);
3626 		str = xrealloc(str, (len + strlen(p) + (2 * nonnull[n])));
3627 		if (n) {
3628 			strcat(str, " ");
3629 		} else {
3630 			*str = '\0';
3631 		}
3632 		if (nonnull[n])
3633 			strcat(str, "'");
3634 		strcat(str, p);
3635 		if (nonnull[n])
3636 			strcat(str, "'");
3637 		len = strlen(str) + 3;
3638 		if (p != inp[n]) free(p);
3639 	}
3640 	len = strlen(str);
3641 	*(str + len) = '\n';
3642 	*(str + len + 1) = '\0';
3643 	return str;
3644 }
3645 
3646 #ifdef __U_BOOT__
3647 static int do_showvar(cmd_tbl_t *cmdtp, int flag, int argc,
3648 		      char * const argv[])
3649 {
3650 	int i, k;
3651 	int rcode = 0;
3652 	struct variables *cur;
3653 
3654 	if (argc == 1) {		/* Print all env variables	*/
3655 		for (cur = top_vars; cur; cur = cur->next) {
3656 			printf ("%s=%s\n", cur->name, cur->value);
3657 			if (ctrlc ()) {
3658 				puts ("\n ** Abort\n");
3659 				return 1;
3660 			}
3661 		}
3662 		return 0;
3663 	}
3664 	for (i = 1; i < argc; ++i) {	/* print single env variables	*/
3665 		char *name = argv[i];
3666 
3667 		k = -1;
3668 		for (cur = top_vars; cur; cur = cur->next) {
3669 			if(strcmp (cur->name, name) == 0) {
3670 				k = 0;
3671 				printf ("%s=%s\n", cur->name, cur->value);
3672 			}
3673 			if (ctrlc ()) {
3674 				puts ("\n ** Abort\n");
3675 				return 1;
3676 			}
3677 		}
3678 		if (k < 0) {
3679 			printf ("## Error: \"%s\" not defined\n", name);
3680 			rcode ++;
3681 		}
3682 	}
3683 	return rcode;
3684 }
3685 
3686 U_BOOT_CMD(
3687 	showvar, CONFIG_SYS_MAXARGS, 1,	do_showvar,
3688 	"print local hushshell variables",
3689 	"\n    - print values of all hushshell variables\n"
3690 	"showvar name ...\n"
3691 	"    - print value of hushshell variable 'name'"
3692 );
3693 
3694 #endif
3695 /****************************************************************************/
3696