xref: /netbsd-src/bin/sh/options.c (revision 3117ece4fc4a4ca4489ba793710b60b0d26bab6c)
1 /*	$NetBSD: options.c,v 1.62 2024/10/14 09:10:35 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 1.62 2024/10/14 09:10:35 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 if (cmdline && c == 'r') {
248 				out1fmt("NetBSD shell: %s\n",
249 				    lookupvar("NETBSD_SHELL"));
250 				sh_exit(0);
251 			} else {
252 				setoption(c, val);
253 			}
254 		}
255 	}
256 }
257 
258 static void
259 set_opt_val(size_t i, int val)
260 {
261 	size_t j;
262 	int flag;
263 
264 	if (val && (flag = optlist[i].opt_set)) {
265 		/* some options (eg vi/emacs) are mutually exclusive */
266 		for (j = 0; j < NOPTS; j++)
267 		    if (optlist[j].opt_set == flag)
268 			optlist[j].val = 0;
269 	}
270 #ifndef SMALL
271 	if (i == _SH_OPT_Xflag)
272 		xtracefdsetup(val);
273 #endif
274 	optlist[i].val = val;
275 #ifdef DEBUG
276 	if (&optlist[i].val == &debug)
277 		opentrace();	/* different "trace" than the -x one... */
278 #endif
279 }
280 
281 STATIC void
282 minus_o(char *name, int val)
283 {
284 	size_t i;
285 	const char *sep = ": ";
286 
287 	if (name == NULL) {
288 		if (val) {
289 			out1str("Current option settings");
290 			for (i = 0; i < NOPTS; i++) {
291 				if (optlist[i].name == NULL)  {
292 					out1fmt("%s%c%c", sep,
293 					    "+-"[optlist[i].val],
294 					    optlist[i].letter);
295 					sep = ", ";
296 				}
297 			}
298 			out1c('\n');
299 			for (i = 0; i < NOPTS; i++) {
300 				if (optlist[i].name)
301 				    out1fmt("%-19s %s\n", optlist[i].name,
302 					optlist[i].val ? "on" : "off");
303 			}
304 		} else {
305 			out1str("set -o default");
306 			for (i = 0; i < NOPTS; i++) {
307 				if (optlist[i].val == optlist[i].dflt)
308 					continue;
309 				if (optlist[i].name)
310 				    out1fmt(" %co %s",
311 					"+-"[optlist[i].val], optlist[i].name);
312 				else
313 				    out1fmt(" %c%c", "+-"[optlist[i].val],
314 					optlist[i].letter);
315 			}
316 			out1c('\n');
317 		}
318 	} else {
319 		if (val == 1 && equal(name, "default")) { /* special case */
320 			for (i = 0; i < NOPTS; i++)
321 				set_opt_val(i, optlist[i].dflt);
322 			return;
323 		}
324 		if (val)
325 			val = 1;
326 		for (i = 0; i < NOPTS; i++)
327 			if (optlist[i].name && equal(name, optlist[i].name)) {
328 				set_opt_val(i, val);
329 #ifndef SMALL
330 				if (i == _SH_OPT_Xflag)
331 					set_opt_val(_SH_OPT_xflag, val);
332 #endif
333 				return;
334 			}
335 		error("Unknown option %co %s", "+-"[val], name);
336 	}
337 }
338 
339 
340 STATIC void
341 setoption(int flag, int val)
342 {
343 	size_t i;
344 
345 	for (i = 0; i < NOPTS; i++)
346 		if (optlist[i].letter == flag) {
347 			set_opt_val(i, val);
348 #ifndef SMALL
349 			if (i == _SH_OPT_Xflag)
350 				set_opt_val(_SH_OPT_xflag, val);
351 #endif
352 			return;
353 		}
354 	error("Unknown option %c%c", "+-"[val], flag);
355 	/* NOTREACHED */
356 }
357 
358 
359 
360 #ifdef mkinit
361 INCLUDE "options.h"
362 
363 SHELLPROC {
364 	int i;
365 
366 	for (i = 0; optlist[i].name; i++)
367 		optlist[i].val = 0;
368 	optschanged();
369 
370 }
371 #endif
372 
373 
374 /*
375  * Set the shell parameters.
376  */
377 
378 void
379 setparam(char **argv)
380 {
381 	char **newparam;
382 	char **ap;
383 	int nparam;
384 
385 	for (nparam = 0 ; argv[nparam] ; nparam++)
386 		continue;
387 	ap = newparam = ckmalloc((nparam + 1) * sizeof *ap);
388 	while (*argv) {
389 		*ap++ = savestr(*argv++);
390 	}
391 	*ap = NULL;
392 	freeparam(&shellparam);
393 	shellparam.malloc = 1;
394 	shellparam.nparam = nparam;
395 	shellparam.p = newparam;
396 	shellparam.optnext = NULL;
397 }
398 
399 
400 /*
401  * Free the list of positional parameters.
402  */
403 
404 void
405 freeparam(volatile struct shparam *param)
406 {
407 	char **ap;
408 
409 	if (param->malloc) {
410 		for (ap = param->p ; *ap ; ap++)
411 			ckfree(*ap);
412 		ckfree(param->p);
413 	}
414 }
415 
416 
417 
418 /*
419  * The shift builtin command.
420  */
421 
422 #ifndef TINY
423 /* first the rotate variant */
424 static inline int
425 rotatecmd(int argc, char **argv)
426 {
427 	int n;
428 	char **ap1, **ap2, **ss;
429 
430 	(void) nextopt(NULL);	/* ignore '--' as leading option */
431 
432 	/*
433 	 * half this is just in case it ever becomes
434 	 * a separate named command, while it remains
435 	 * puerly an inline inside shift, the compiler
436 	 * should optimise most of it to nothingness
437 	 */
438 	if (argptr[0] && argptr[1])
439 		error("Usage: rotate [n]");
440 	n = 1;
441 	if (*argptr) {
442 		if (**argptr == '-')
443 			n = number(*argptr + 1);
444 		else		/* anti-clockwise n == clockwise $# - n */
445 			n = shellparam.nparam - number(*argptr);
446 	}
447 
448 	if (n == 0 || n == shellparam.nparam)		/* nothing to do */
449 		return 0;
450 
451 	if (n < 0 || n > shellparam.nparam)
452 		error("can't rotate that many");
453 
454 	ap2 = ss = (char **)stalloc(n * sizeof(char *));
455 	INTOFF;
456 	for (ap1 = shellparam.p + shellparam.nparam - n;
457 	     ap1 < shellparam.p + shellparam.nparam; )
458 		*ap2++ = *ap1++;
459 	for (ap2 = shellparam.p + shellparam.nparam, ap1 = ap2 - n;
460 	     ap1 > shellparam.p; )
461 		*--ap2 = *--ap1;
462 	for (ap1 = ss + n; ap1 > ss; )
463 		*--ap2 = *--ap1;
464 	shellparam.optnext = NULL;
465 	INTON;
466 	stunalloc(ss);
467 
468 	return 0;
469 }
470 #endif
471 
472 int
473 shiftcmd(int argc, char **argv)
474 {
475 	int n;
476 	char **ap1, **ap2;
477 
478 	(void) nextopt(NULL);	/* ignore '--' as leading option */
479 
480 	if (argptr[0] && argptr[1])
481 		error("Usage: shift [n]");
482 
483 #ifndef TINY
484 	if (*argptr && **argptr == '-') {
485 		argptr = argv + 1;	/* reinit nextopt() */
486 		optptr = NULL;
487 		return rotatecmd(argc, argv);
488 	}
489 #endif
490 
491 	n = 1;
492 	if (*argptr)
493 		n = number(*argptr);
494 	if (n > shellparam.nparam)
495 		error("can't shift that many");
496 	INTOFF;
497 	shellparam.nparam -= n;
498 	for (ap1 = shellparam.p ; --n >= 0 ; ap1++) {
499 		if (shellparam.malloc)
500 			ckfree(*ap1);
501 	}
502 	ap2 = shellparam.p;
503 	while ((*ap2++ = *ap1++) != NULL)
504 		continue;
505 	shellparam.optnext = NULL;
506 	INTON;
507 	return 0;
508 }
509 
510 
511 
512 /*
513  * The set command builtin.
514  */
515 
516 int
517 setcmd(int argc, char **argv)
518 {
519 	if (argc == 1)
520 		return showvars(0, 0, 1, 0);
521 	INTOFF;
522 	options(0);
523 	optschanged();
524 	if (*argptr != NULL) {
525 		setparam(argptr);
526 	}
527 	INTON;
528 	return 0;
529 }
530 
531 
532 void
533 getoptsreset(char *value, int flags __unused)
534 {
535 	/*
536 	 * This is just to detect the case where OPTIND=1
537 	 * is executed.   Any other string assigned to OPTIND
538 	 * is OK, but is not a reset.   No errors, so cannot use number()
539 	 */
540 	if (is_digit(*value) && strtol(value, NULL, 10) == 1) {
541 		shellparam.optnext = NULL;
542 		shellparam.reset = 1;
543 	}
544 }
545 
546 /*
547  * The getopts builtin.  Shellparam.optnext points to the next argument
548  * to be processed.  Shellparam.optptr points to the next character to
549  * be processed in the current argument.  If shellparam.optnext is NULL,
550  * then it's the first time getopts has been called.
551  */
552 
553 int
554 getoptscmd(int argc, char **argv)
555 {
556 	char **optbase;
557 
558 	if (argc < 3)
559 		error("usage: getopts optstring var [arg]");
560 	else if (argc == 3)
561 		optbase = shellparam.p;
562 	else
563 		optbase = &argv[3];
564 
565 	if (shellparam.reset == 1) {
566 		shellparam.optnext = optbase;
567 		shellparam.optptr = NULL;
568 		shellparam.reset = 0;
569 	}
570 
571 	return getopts(argv[1], argv[2], optbase, &shellparam.optnext,
572 		       &shellparam.optptr);
573 }
574 
575 STATIC int
576 getopts(char *optstr, char *optvar, char **optfirst, char ***optnext, char **optpptr)
577 {
578 	char *p, *q;
579 	char c = '?';
580 	int done = 0;
581 	int ind = 0;
582 	int err = 0;
583 	char s[12];
584 
585 	if ((p = *optpptr) == NULL || *p == '\0') {
586 		/* Current word is done, advance */
587 		if (*optnext == NULL)
588 			return 1;
589 		p = **optnext;
590 		if (p == NULL || *p != '-' || *++p == '\0') {
591 atend:
592 			ind = *optnext - optfirst + 1;
593 			*optnext = NULL;
594 			p = NULL;
595 			done = 1;
596 			goto out;
597 		}
598 		(*optnext)++;
599 		if (p[0] == '-' && p[1] == '\0')	/* check for "--" */
600 			goto atend;
601 	}
602 
603 	c = *p++;
604 	for (q = optstr; *q != c; ) {
605 		if (*q == '\0') {
606 			if (optstr[0] == ':') {
607 				s[0] = c;
608 				s[1] = '\0';
609 				err |= setvarsafe("OPTARG", s, 0);
610 			} else {
611 				outfmt(&errout, "Unknown option -%c\n", c);
612 				(void) unsetvar("OPTARG", 0);
613 			}
614 			c = '?';
615 			goto bad;
616 		}
617 		if (*++q == ':')
618 			q++;
619 	}
620 
621 	if (*++q == ':') {
622 		if (*p == '\0' && (p = **optnext) == NULL) {
623 			if (optstr[0] == ':') {
624 				s[0] = c;
625 				s[1] = '\0';
626 				err |= setvarsafe("OPTARG", s, 0);
627 				c = ':';
628 			} else {
629 				outfmt(&errout, "No arg for -%c option\n", c);
630 				(void) unsetvar("OPTARG", 0);
631 				c = '?';
632 			}
633 			goto bad;
634 		}
635 
636 		if (p == **optnext)
637 			(*optnext)++;
638 		err |= setvarsafe("OPTARG", p, 0);
639 		p = NULL;
640 	} else
641 		err |= setvarsafe("OPTARG", "", 0);
642 	ind = *optnext - optfirst + 1;
643 	goto out;
644 
645 bad:
646 	ind = 1;
647 	*optnext = NULL;
648 	p = NULL;
649 out:
650 	*optpptr = p;
651 	fmtstr(s, sizeof(s), "%d", ind);
652 	err |= setvarsafe("OPTIND", s, VNOFUNC);
653 	s[0] = c;
654 	s[1] = '\0';
655 	err |= setvarsafe(optvar, s, 0);
656 	if (err) {
657 		*optnext = NULL;
658 		*optpptr = NULL;
659 		flushall();
660 		exraise(EXERROR);
661 	}
662 	return done;
663 }
664 
665 /*
666  * XXX - should get rid of.  have all builtins use getopt(3).  the
667  * library getopt must have the BSD extension static variable "optreset"
668  * otherwise it can't be used within the shell safely.
669  *
670  * Standard option processing (a la getopt) for builtin routines.  The
671  * only argument that is passed to nextopt is the option string; the
672  * other arguments are unnecessary.  It return the character, or '\0' on
673  * end of input.  If optstring is NULL, then there are no options, and
674  * args are allowed to begin with '-', but a single leading "--" will be
675  * discarded.   This is for some POSIX special builtins that require
676  * -- processing, have no args, and we never did opt processing before
677  * and need to retain backwards compat.
678  */
679 
680 int
681 nextopt(const char *optstring)
682 {
683 	char *p;
684 	const char *q;
685 	char c;
686 
687 	if ((p = optptr) == NULL || *p == '\0') {
688 		p = *argptr;
689 		if (p == NULL || *p != '-' || *++p == '\0')
690 			return '\0';
691 		argptr++;
692 		if (p[0] == '-' && p[1] == '\0')	/* check for "--" */
693 			return '\0';
694 		if (optstring == NULL)	/* not processing the "option" */
695 			argptr--;	/* so make it be an arg again */
696 	}
697 	if (optstring == NULL)
698 		return '\0';
699 	c = *p++;
700 	for (q = optstring ; *q != c ; ) {
701 		if (*q == '\0')
702 			error("Unknown option -%c", c);
703 		if (*++q == ':')
704 			q++;
705 	}
706 	if (*++q == ':') {
707 		if (*p == '\0' && (p = *argptr++) == NULL)
708 			error("No arg for -%c option", c);
709 		optionarg = p;
710 		p = NULL;
711 	}
712 	optptr = p;
713 	return c;
714 }
715