xref: /netbsd-src/bin/sh/options.c (revision ccd9df534e375a4366c5b55f23782053c7a98d82)
1 /*	$NetBSD: options.c,v 1.58 2022/09/18 06:03:19 kre Exp $	*/
2 
3 /*-
4  * Copyright (c) 1991, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Kenneth Almquist.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include <sys/cdefs.h>
36 #ifndef lint
37 #if 0
38 static char sccsid[] = "@(#)options.c	8.2 (Berkeley) 5/4/95";
39 #else
40 __RCSID("$NetBSD: options.c,v 1.58 2022/09/18 06:03:19 kre Exp $");
41 #endif
42 #endif /* not lint */
43 
44 #include <signal.h>
45 #include <unistd.h>
46 #include <stdlib.h>
47 
48 #include "shell.h"
49 #define DEFINE_OPTIONS
50 #include "options.h"
51 #undef DEFINE_OPTIONS
52 #include "builtins.h"
53 #include "nodes.h"	/* for other header files */
54 #include "eval.h"
55 #include "jobs.h"
56 #include "input.h"
57 #include "output.h"
58 #include "trap.h"
59 #include "var.h"
60 #include "memalloc.h"
61 #include "error.h"
62 #include "mystring.h"
63 #include "syntax.h"
64 #ifndef SMALL
65 #include "myhistedit.h"
66 #endif
67 #include "show.h"
68 
69 char *arg0;			/* value of $0 */
70 struct shparam shellparam;	/* current positional parameters */
71 char **argptr;			/* argument list for builtin commands */
72 char *optionarg;		/* set by nextopt (like getopt) */
73 char *optptr;			/* used by nextopt */
74 
75 char *minusc;			/* argument to -c option */
76 
77 
78 STATIC void options(int);
79 STATIC void minus_o(char *, int);
80 STATIC void setoption(int, int);
81 STATIC int getopts(char *, char *, char **, char ***, char **);
82 
83 
84 /*
85  * Process the shell command line arguments.
86  */
87 
88 void
89 procargs(int argc, char **argv)
90 {
91 	size_t i;
92 	int psx;
93 
94 	argptr = argv;
95 	if (argc > 0)
96 		argptr++;
97 
98 	psx = posix;		/* save what we set it to earlier */
99 	/*
100 	 * option values are mostly boolean 0:off 1:on
101 	 * we use 2 (just in this routine) to mean "unknown yet"
102 	 */
103 	for (i = 0; i < NOPTS; i++)
104 		optlist[i].val = 2;
105 	posix = psx;		/* restore before processing -o ... */
106 
107 	options(1);
108 
109 	if (*argptr == NULL && minusc == NULL)
110 		sflag = 1;
111 	if (iflag == 2 && sflag == 1 && isatty(0) && isatty(2))
112 		iflag = 1;
113 	if (iflag == 1 && sflag == 2)
114 		iflag = 2;
115 	if (mflag == 2)
116 		mflag = iflag;
117 #ifndef DO_SHAREDVFORK
118 	if (usefork == 2)
119 		usefork = 1;
120 #endif
121 #if DEBUG >= 2
122 	if (debug == 2)
123 		debug = 1;
124 #endif
125 	arg0 = argv[0];
126 	if (loginsh == 2 && arg0 != NULL && arg0[0] == '-')
127 		loginsh = 1;
128 
129 	/*
130 	 * Any options not dealt with as special cases just above,
131 	 * and which were not set on the command line, are set to
132 	 * their expected default values (mostly "off")
133 	 *
134 	 * then as each option is initialised, save its setting now
135 	 * as its "default" value for future use ("set -o default").
136 	 */
137 	for (i = 0; i < NOPTS; i++) {
138 		if (optlist[i].val == 2)
139 			optlist[i].val = optlist[i].dflt;
140 		optlist[i].dflt = optlist[i].val;
141 	}
142 
143 	if (sflag == 0 && minusc == NULL) {
144 		commandname = argv[0];
145 		arg0 = *argptr++;
146 		setinputfile(arg0, 0);
147 		commandname = arg0;
148 	}
149 	/* POSIX 1003.2: first arg after -c cmd is $0, remainder $1... */
150 	if (minusc != NULL) {
151 		if (argptr == NULL || *argptr == NULL)
152 			error("Bad -c option");
153 		minusc = *argptr++;
154 		if (*argptr != 0)
155 			arg0 = *argptr++;
156 	}
157 
158 	shellparam.p = argptr;
159 	shellparam.reset = 1;
160 	/* assert(shellparam.malloc == 0 && shellparam.nparam == 0); */
161 	while (*argptr) {
162 		shellparam.nparam++;
163 		argptr++;
164 	}
165 	optschanged();
166 }
167 
168 
169 void
170 optschanged(void)
171 {
172 	setinteractive(iflag);
173 #ifndef SMALL
174 	histedit();
175 #endif
176 	setjobctl(mflag);
177 
178 	if (privileged && !pflag) {
179 		setuid(getuid());
180 		setgid(getgid());
181 		privileged = 0;
182 		setvarsafe("PSc", (getuid() == 0 ? "#" : "$"), 0);
183 	}
184 }
185 
186 /*
187  * Process shell options.  The global variable argptr contains a pointer
188  * to the argument list; we advance it past the options.
189  */
190 
191 STATIC void
192 options(int cmdline)
193 {
194 	static char empty[] = "";
195 	char *p;
196 	int val;
197 	int c;
198 
199 	if (cmdline)
200 		minusc = NULL;
201 	while ((p = *argptr) != NULL) {
202 		argptr++;
203 		if ((c = *p++) == '-') {
204 			val = 1;
205                         if (p[0] == '\0' || (p[0] == '-' && p[1] == '\0')) {
206                                 if (!cmdline) {
207                                         /* "-" means turn off -x and -v */
208                                         if (p[0] == '\0')
209                                                 xflag = vflag = 0;
210                                         /* "--" means reset params */
211                                         else if (*argptr == NULL)
212 						setparam(argptr);
213                                 }
214 				break;	  /* "-" or  "--" terminates options */
215 			}
216 		} else if (c == '+') {
217 			val = 0;
218 		} else {
219 			argptr--;
220 			break;
221 		}
222 		while ((c = *p++) != '\0') {
223 			if (val == 1 && c == 'c' && cmdline) {
224 				/* command is after shell args*/
225 				minusc = empty;
226 			} else if (c == 'o') {
227 				if (*p != '\0')
228 					minus_o(p, val + (cmdline ? val : 0));
229 				else if (*argptr)
230 					minus_o(*argptr++,
231 					    val + (cmdline ? val : 0));
232 				else if (!cmdline)
233 					minus_o(NULL, val);
234 				else
235 					error("arg for %co missing", "+-"[val]);
236 				break;
237 #ifdef DEBUG
238 			} else if (c == 'D') {
239 				if (*p) {
240 					set_debug(p, val);
241 					break;
242 				} else if (*argptr)
243 					set_debug(*argptr++, val);
244 				else
245 					set_debug("*$", val);
246 #endif
247 			} else {
248 				setoption(c, val);
249 			}
250 		}
251 	}
252 }
253 
254 static void
255 set_opt_val(size_t i, int val)
256 {
257 	size_t j;
258 	int flag;
259 
260 	if (val && (flag = optlist[i].opt_set)) {
261 		/* some options (eg vi/emacs) are mutually exclusive */
262 		for (j = 0; j < NOPTS; j++)
263 		    if (optlist[j].opt_set == flag)
264 			optlist[j].val = 0;
265 	}
266 #ifndef SMALL
267 	if (i == _SH_OPT_Xflag)
268 		xtracefdsetup(val);
269 #endif
270 	optlist[i].val = val;
271 #ifdef DEBUG
272 	if (&optlist[i].val == &debug)
273 		opentrace();	/* different "trace" than the -x one... */
274 #endif
275 }
276 
277 STATIC void
278 minus_o(char *name, int val)
279 {
280 	size_t i;
281 	const char *sep = ": ";
282 
283 	if (name == NULL) {
284 		if (val) {
285 			out1str("Current option settings");
286 			for (i = 0; i < NOPTS; i++) {
287 				if (optlist[i].name == NULL)  {
288 					out1fmt("%s%c%c", sep,
289 					    "+-"[optlist[i].val],
290 					    optlist[i].letter);
291 					sep = ", ";
292 				}
293 			}
294 			out1c('\n');
295 			for (i = 0; i < NOPTS; i++) {
296 				if (optlist[i].name)
297 				    out1fmt("%-19s %s\n", optlist[i].name,
298 					optlist[i].val ? "on" : "off");
299 			}
300 		} else {
301 			out1str("set -o default");
302 			for (i = 0; i < NOPTS; i++) {
303 				if (optlist[i].val == optlist[i].dflt)
304 					continue;
305 				if (optlist[i].name)
306 				    out1fmt(" %co %s",
307 					"+-"[optlist[i].val], optlist[i].name);
308 				else
309 				    out1fmt(" %c%c", "+-"[optlist[i].val],
310 					optlist[i].letter);
311 			}
312 			out1c('\n');
313 		}
314 	} else {
315 		if (val == 1 && equal(name, "default")) { /* special case */
316 			for (i = 0; i < NOPTS; i++)
317 				set_opt_val(i, optlist[i].dflt);
318 			return;
319 		}
320 		if (val)
321 			val = 1;
322 		for (i = 0; i < NOPTS; i++)
323 			if (optlist[i].name && equal(name, optlist[i].name)) {
324 				set_opt_val(i, val);
325 #ifndef SMALL
326 				if (i == _SH_OPT_Xflag)
327 					set_opt_val(_SH_OPT_xflag, val);
328 #endif
329 				return;
330 			}
331 		error("Unknown option %co %s", "+-"[val], name);
332 	}
333 }
334 
335 
336 STATIC void
337 setoption(int flag, int val)
338 {
339 	size_t i;
340 
341 	for (i = 0; i < NOPTS; i++)
342 		if (optlist[i].letter == flag) {
343 			set_opt_val(i, val);
344 #ifndef SMALL
345 			if (i == _SH_OPT_Xflag)
346 				set_opt_val(_SH_OPT_xflag, val);
347 #endif
348 			return;
349 		}
350 	error("Unknown option %c%c", "+-"[val], flag);
351 	/* NOTREACHED */
352 }
353 
354 
355 
356 #ifdef mkinit
357 INCLUDE "options.h"
358 
359 SHELLPROC {
360 	int i;
361 
362 	for (i = 0; optlist[i].name; i++)
363 		optlist[i].val = 0;
364 	optschanged();
365 
366 }
367 #endif
368 
369 
370 /*
371  * Set the shell parameters.
372  */
373 
374 void
375 setparam(char **argv)
376 {
377 	char **newparam;
378 	char **ap;
379 	int nparam;
380 
381 	for (nparam = 0 ; argv[nparam] ; nparam++)
382 		continue;
383 	ap = newparam = ckmalloc((nparam + 1) * sizeof *ap);
384 	while (*argv) {
385 		*ap++ = savestr(*argv++);
386 	}
387 	*ap = NULL;
388 	freeparam(&shellparam);
389 	shellparam.malloc = 1;
390 	shellparam.nparam = nparam;
391 	shellparam.p = newparam;
392 	shellparam.optnext = NULL;
393 }
394 
395 
396 /*
397  * Free the list of positional parameters.
398  */
399 
400 void
401 freeparam(volatile struct shparam *param)
402 {
403 	char **ap;
404 
405 	if (param->malloc) {
406 		for (ap = param->p ; *ap ; ap++)
407 			ckfree(*ap);
408 		ckfree(param->p);
409 	}
410 }
411 
412 
413 
414 /*
415  * The shift builtin command.
416  */
417 
418 int
419 shiftcmd(int argc, char **argv)
420 {
421 	int n;
422 	char **ap1, **ap2;
423 
424 	if (argc > 2)
425 		error("Usage: shift [n]");
426 	n = 1;
427 	if (argc > 1)
428 		n = number(argv[1]);
429 	if (n > shellparam.nparam)
430 		error("can't shift that many");
431 	INTOFF;
432 	shellparam.nparam -= n;
433 	for (ap1 = shellparam.p ; --n >= 0 ; ap1++) {
434 		if (shellparam.malloc)
435 			ckfree(*ap1);
436 	}
437 	ap2 = shellparam.p;
438 	while ((*ap2++ = *ap1++) != NULL)
439 		continue;
440 	shellparam.optnext = NULL;
441 	INTON;
442 	return 0;
443 }
444 
445 
446 
447 /*
448  * The set command builtin.
449  */
450 
451 int
452 setcmd(int argc, char **argv)
453 {
454 	if (argc == 1)
455 		return showvars(0, 0, 1, 0);
456 	INTOFF;
457 	options(0);
458 	optschanged();
459 	if (*argptr != NULL) {
460 		setparam(argptr);
461 	}
462 	INTON;
463 	return 0;
464 }
465 
466 
467 void
468 getoptsreset(const char *value)
469 {
470 	/*
471 	 * This is just to detect the case where OPTIND=1
472 	 * is executed.   Any other string assigned to OPTIND
473 	 * is OK, but is not a reset.   No errors, so cannot use number()
474 	 */
475 	if (is_digit(*value) && strtol(value, NULL, 10) == 1) {
476 		shellparam.optnext = NULL;
477 		shellparam.reset = 1;
478 	}
479 }
480 
481 /*
482  * The getopts builtin.  Shellparam.optnext points to the next argument
483  * to be processed.  Shellparam.optptr points to the next character to
484  * be processed in the current argument.  If shellparam.optnext is NULL,
485  * then it's the first time getopts has been called.
486  */
487 
488 int
489 getoptscmd(int argc, char **argv)
490 {
491 	char **optbase;
492 
493 	if (argc < 3)
494 		error("usage: getopts optstring var [arg]");
495 	else if (argc == 3)
496 		optbase = shellparam.p;
497 	else
498 		optbase = &argv[3];
499 
500 	if (shellparam.reset == 1) {
501 		shellparam.optnext = optbase;
502 		shellparam.optptr = NULL;
503 		shellparam.reset = 0;
504 	}
505 
506 	return getopts(argv[1], argv[2], optbase, &shellparam.optnext,
507 		       &shellparam.optptr);
508 }
509 
510 STATIC int
511 getopts(char *optstr, char *optvar, char **optfirst, char ***optnext, char **optpptr)
512 {
513 	char *p, *q;
514 	char c = '?';
515 	int done = 0;
516 	int ind = 0;
517 	int err = 0;
518 	char s[12];
519 
520 	if ((p = *optpptr) == NULL || *p == '\0') {
521 		/* Current word is done, advance */
522 		if (*optnext == NULL)
523 			return 1;
524 		p = **optnext;
525 		if (p == NULL || *p != '-' || *++p == '\0') {
526 atend:
527 			ind = *optnext - optfirst + 1;
528 			*optnext = NULL;
529 			p = NULL;
530 			done = 1;
531 			goto out;
532 		}
533 		(*optnext)++;
534 		if (p[0] == '-' && p[1] == '\0')	/* check for "--" */
535 			goto atend;
536 	}
537 
538 	c = *p++;
539 	for (q = optstr; *q != c; ) {
540 		if (*q == '\0') {
541 			if (optstr[0] == ':') {
542 				s[0] = c;
543 				s[1] = '\0';
544 				err |= setvarsafe("OPTARG", s, 0);
545 			} else {
546 				outfmt(&errout, "Unknown option -%c\n", c);
547 				(void) unsetvar("OPTARG", 0);
548 			}
549 			c = '?';
550 			goto bad;
551 		}
552 		if (*++q == ':')
553 			q++;
554 	}
555 
556 	if (*++q == ':') {
557 		if (*p == '\0' && (p = **optnext) == NULL) {
558 			if (optstr[0] == ':') {
559 				s[0] = c;
560 				s[1] = '\0';
561 				err |= setvarsafe("OPTARG", s, 0);
562 				c = ':';
563 			} else {
564 				outfmt(&errout, "No arg for -%c option\n", c);
565 				(void) unsetvar("OPTARG", 0);
566 				c = '?';
567 			}
568 			goto bad;
569 		}
570 
571 		if (p == **optnext)
572 			(*optnext)++;
573 		err |= setvarsafe("OPTARG", p, 0);
574 		p = NULL;
575 	} else
576 		err |= setvarsafe("OPTARG", "", 0);
577 	ind = *optnext - optfirst + 1;
578 	goto out;
579 
580 bad:
581 	ind = 1;
582 	*optnext = NULL;
583 	p = NULL;
584 out:
585 	*optpptr = p;
586 	fmtstr(s, sizeof(s), "%d", ind);
587 	err |= setvarsafe("OPTIND", s, VNOFUNC);
588 	s[0] = c;
589 	s[1] = '\0';
590 	err |= setvarsafe(optvar, s, 0);
591 	if (err) {
592 		*optnext = NULL;
593 		*optpptr = NULL;
594 		flushall();
595 		exraise(EXERROR);
596 	}
597 	return done;
598 }
599 
600 /*
601  * XXX - should get rid of.  have all builtins use getopt(3).  the
602  * library getopt must have the BSD extension static variable "optreset"
603  * otherwise it can't be used within the shell safely.
604  *
605  * Standard option processing (a la getopt) for builtin routines.  The
606  * only argument that is passed to nextopt is the option string; the
607  * other arguments are unnecessary.  It return the character, or '\0' on
608  * end of input.  If optstring is NULL, then there are no options, and
609  * args are allowed to begin with '-', but a single leading "--" will be
610  * discarded.   This is for some POSIX special builtins that require
611  * -- processing, have no args, and we never did opt processing before
612  * and need to retain backwards compat.
613  */
614 
615 int
616 nextopt(const char *optstring)
617 {
618 	char *p;
619 	const char *q;
620 	char c;
621 
622 	if ((p = optptr) == NULL || *p == '\0') {
623 		p = *argptr;
624 		if (p == NULL || *p != '-' || *++p == '\0')
625 			return '\0';
626 		argptr++;
627 		if (p[0] == '-' && p[1] == '\0')	/* check for "--" */
628 			return '\0';
629 		if (optstring == NULL)	/* not processing the "option" */
630 			argptr--;	/* so make it be an arg again */
631 	}
632 	if (optstring == NULL)
633 		return '\0';
634 	c = *p++;
635 	for (q = optstring ; *q != c ; ) {
636 		if (*q == '\0')
637 			error("Unknown option -%c", c);
638 		if (*++q == ':')
639 			q++;
640 	}
641 	if (*++q == ':') {
642 		if (*p == '\0' && (p = *argptr++) == NULL)
643 			error("No arg for -%c option", c);
644 		optionarg = p;
645 		p = NULL;
646 	}
647 	optptr = p;
648 	return c;
649 }
650