xref: /netbsd-src/bin/sh/options.c (revision 53b02e147d4ed531c0d2a5ca9b3e8026ba3e99b5)
1 /*	$NetBSD: options.c,v 1.56 2021/10/26 00:05:38 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 1.56 2021/10/26 00:05:38 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 	/*
126 	 * Any options not dealt with as special cases just above,
127 	 * and which were not set on the command line, are set to
128 	 * their expected default values (mostly "off")
129 	 *
130 	 * then as each option is initialised, save its setting now
131 	 * as its "default" value for future use ("set -o default").
132 	 */
133 	for (i = 0; i < NOPTS; i++) {
134 		if (optlist[i].val == 2)
135 			optlist[i].val = optlist[i].dflt;
136 		optlist[i].dflt = optlist[i].val;
137 	}
138 
139 	arg0 = argv[0];
140 	if (sflag == 0 && minusc == NULL) {
141 		commandname = argv[0];
142 		arg0 = *argptr++;
143 		setinputfile(arg0, 0);
144 		commandname = arg0;
145 	}
146 	/* POSIX 1003.2: first arg after -c cmd is $0, remainder $1... */
147 	if (minusc != NULL) {
148 		if (argptr == NULL || *argptr == NULL)
149 			error("Bad -c option");
150 		minusc = *argptr++;
151 		if (*argptr != 0)
152 			arg0 = *argptr++;
153 	}
154 
155 	shellparam.p = argptr;
156 	shellparam.reset = 1;
157 	/* assert(shellparam.malloc == 0 && shellparam.nparam == 0); */
158 	while (*argptr) {
159 		shellparam.nparam++;
160 		argptr++;
161 	}
162 	optschanged();
163 }
164 
165 
166 void
167 optschanged(void)
168 {
169 	setinteractive(iflag);
170 #ifndef SMALL
171 	histedit();
172 #endif
173 	setjobctl(mflag);
174 
175 	if (privileged && !pflag) {
176 		setuid(getuid());
177 		setgid(getgid());
178 		privileged = 0;
179 		setvarsafe("PSc", (getuid() == 0 ? "#" : "$"), 0);
180 	}
181 }
182 
183 /*
184  * Process shell options.  The global variable argptr contains a pointer
185  * to the argument list; we advance it past the options.
186  */
187 
188 STATIC void
189 options(int cmdline)
190 {
191 	static char empty[] = "";
192 	char *p;
193 	int val;
194 	int c;
195 
196 	if (cmdline)
197 		minusc = NULL;
198 	while ((p = *argptr) != NULL) {
199 		argptr++;
200 		if ((c = *p++) == '-') {
201 			val = 1;
202                         if (p[0] == '\0' || (p[0] == '-' && p[1] == '\0')) {
203                                 if (!cmdline) {
204                                         /* "-" means turn off -x and -v */
205                                         if (p[0] == '\0')
206                                                 xflag = vflag = 0;
207                                         /* "--" means reset params */
208                                         else if (*argptr == NULL)
209 						setparam(argptr);
210                                 }
211 				break;	  /* "-" or  "--" terminates options */
212 			}
213 		} else if (c == '+') {
214 			val = 0;
215 		} else {
216 			argptr--;
217 			break;
218 		}
219 		while ((c = *p++) != '\0') {
220 			if (val == 1 && c == 'c' && cmdline) {
221 				/* command is after shell args*/
222 				minusc = empty;
223 			} else if (c == 'o') {
224 				if (*p != '\0')
225 					minus_o(p, val + (cmdline ? val : 0));
226 				else if (*argptr)
227 					minus_o(*argptr++,
228 					    val + (cmdline ? val : 0));
229 				else if (!cmdline)
230 					minus_o(NULL, val);
231 				else
232 					error("arg for %co missing", "+-"[val]);
233 				break;
234 #ifdef DEBUG
235 			} else if (c == 'D') {
236 				if (*p) {
237 					set_debug(p, val);
238 					break;
239 				} else if (*argptr)
240 					set_debug(*argptr++, val);
241 				else
242 					set_debug("*$", val);
243 #endif
244 			} else {
245 				setoption(c, val);
246 			}
247 		}
248 	}
249 }
250 
251 static void
252 set_opt_val(size_t i, int val)
253 {
254 	size_t j;
255 	int flag;
256 
257 	if (val && (flag = optlist[i].opt_set)) {
258 		/* some options (eg vi/emacs) are mutually exclusive */
259 		for (j = 0; j < NOPTS; j++)
260 		    if (optlist[j].opt_set == flag)
261 			optlist[j].val = 0;
262 	}
263 #ifndef SMALL
264 	if (i == _SH_OPT_Xflag)
265 		xtracefdsetup(val);
266 #endif
267 	optlist[i].val = val;
268 #ifdef DEBUG
269 	if (&optlist[i].val == &debug)
270 		opentrace();	/* different "trace" than the -x one... */
271 #endif
272 }
273 
274 STATIC void
275 minus_o(char *name, int val)
276 {
277 	size_t i;
278 	const char *sep = ": ";
279 
280 	if (name == NULL) {
281 		if (val) {
282 			out1str("Current option settings");
283 			for (i = 0; i < NOPTS; i++) {
284 				if (optlist[i].name == NULL)  {
285 					out1fmt("%s%c%c", sep,
286 					    "+-"[optlist[i].val],
287 					    optlist[i].letter);
288 					sep = ", ";
289 				}
290 			}
291 			out1c('\n');
292 			for (i = 0; i < NOPTS; i++) {
293 				if (optlist[i].name)
294 				    out1fmt("%-19s %s\n", optlist[i].name,
295 					optlist[i].val ? "on" : "off");
296 			}
297 		} else {
298 			out1str("set -o default");
299 			for (i = 0; i < NOPTS; i++) {
300 				if (optlist[i].val == optlist[i].dflt)
301 					continue;
302 				if (optlist[i].name)
303 				    out1fmt(" %co %s",
304 					"+-"[optlist[i].val], optlist[i].name);
305 				else
306 				    out1fmt(" %c%c", "+-"[optlist[i].val],
307 					optlist[i].letter);
308 			}
309 			out1c('\n');
310 		}
311 	} else {
312 		if (val == 1 && equal(name, "default")) { /* special case */
313 			for (i = 0; i < NOPTS; i++)
314 				set_opt_val(i, optlist[i].dflt);
315 			return;
316 		}
317 		if (val)
318 			val = 1;
319 		for (i = 0; i < NOPTS; i++)
320 			if (optlist[i].name && equal(name, optlist[i].name)) {
321 				set_opt_val(i, val);
322 #ifndef SMALL
323 				if (i == _SH_OPT_Xflag)
324 					set_opt_val(_SH_OPT_xflag, val);
325 #endif
326 				return;
327 			}
328 		error("Illegal option %co %s", "+-"[val], name);
329 	}
330 }
331 
332 
333 STATIC void
334 setoption(int flag, int val)
335 {
336 	size_t i;
337 
338 	for (i = 0; i < NOPTS; i++)
339 		if (optlist[i].letter == flag) {
340 			set_opt_val(i, val);
341 #ifndef SMALL
342 			if (i == _SH_OPT_Xflag)
343 				set_opt_val(_SH_OPT_xflag, val);
344 #endif
345 			return;
346 		}
347 	error("Illegal option %c%c", "+-"[val], flag);
348 	/* NOTREACHED */
349 }
350 
351 
352 
353 #ifdef mkinit
354 INCLUDE "options.h"
355 
356 SHELLPROC {
357 	int i;
358 
359 	for (i = 0; optlist[i].name; i++)
360 		optlist[i].val = 0;
361 	optschanged();
362 
363 }
364 #endif
365 
366 
367 /*
368  * Set the shell parameters.
369  */
370 
371 void
372 setparam(char **argv)
373 {
374 	char **newparam;
375 	char **ap;
376 	int nparam;
377 
378 	for (nparam = 0 ; argv[nparam] ; nparam++)
379 		continue;
380 	ap = newparam = ckmalloc((nparam + 1) * sizeof *ap);
381 	while (*argv) {
382 		*ap++ = savestr(*argv++);
383 	}
384 	*ap = NULL;
385 	freeparam(&shellparam);
386 	shellparam.malloc = 1;
387 	shellparam.nparam = nparam;
388 	shellparam.p = newparam;
389 	shellparam.optnext = NULL;
390 }
391 
392 
393 /*
394  * Free the list of positional parameters.
395  */
396 
397 void
398 freeparam(volatile struct shparam *param)
399 {
400 	char **ap;
401 
402 	if (param->malloc) {
403 		for (ap = param->p ; *ap ; ap++)
404 			ckfree(*ap);
405 		ckfree(param->p);
406 	}
407 }
408 
409 
410 
411 /*
412  * The shift builtin command.
413  */
414 
415 int
416 shiftcmd(int argc, char **argv)
417 {
418 	int n;
419 	char **ap1, **ap2;
420 
421 	if (argc > 2)
422 		error("Usage: shift [n]");
423 	n = 1;
424 	if (argc > 1)
425 		n = number(argv[1]);
426 	if (n > shellparam.nparam)
427 		error("can't shift that many");
428 	INTOFF;
429 	shellparam.nparam -= n;
430 	for (ap1 = shellparam.p ; --n >= 0 ; ap1++) {
431 		if (shellparam.malloc)
432 			ckfree(*ap1);
433 	}
434 	ap2 = shellparam.p;
435 	while ((*ap2++ = *ap1++) != NULL)
436 		continue;
437 	shellparam.optnext = NULL;
438 	INTON;
439 	return 0;
440 }
441 
442 
443 
444 /*
445  * The set command builtin.
446  */
447 
448 int
449 setcmd(int argc, char **argv)
450 {
451 	if (argc == 1)
452 		return showvars(0, 0, 1, 0);
453 	INTOFF;
454 	options(0);
455 	optschanged();
456 	if (*argptr != NULL) {
457 		setparam(argptr);
458 	}
459 	INTON;
460 	return 0;
461 }
462 
463 
464 void
465 getoptsreset(const char *value)
466 {
467 	/*
468 	 * This is just to detect the case where OPTIND=1
469 	 * is executed.   Any other string assigned to OPTIND
470 	 * is OK, but is not a reset.   No errors, so cannot use number()
471 	 */
472 	if (is_digit(*value) && strtol(value, NULL, 10) == 1) {
473 		shellparam.optnext = NULL;
474 		shellparam.reset = 1;
475 	}
476 }
477 
478 /*
479  * The getopts builtin.  Shellparam.optnext points to the next argument
480  * to be processed.  Shellparam.optptr points to the next character to
481  * be processed in the current argument.  If shellparam.optnext is NULL,
482  * then it's the first time getopts has been called.
483  */
484 
485 int
486 getoptscmd(int argc, char **argv)
487 {
488 	char **optbase;
489 
490 	if (argc < 3)
491 		error("usage: getopts optstring var [arg]");
492 	else if (argc == 3)
493 		optbase = shellparam.p;
494 	else
495 		optbase = &argv[3];
496 
497 	if (shellparam.reset == 1) {
498 		shellparam.optnext = optbase;
499 		shellparam.optptr = NULL;
500 		shellparam.reset = 0;
501 	}
502 
503 	return getopts(argv[1], argv[2], optbase, &shellparam.optnext,
504 		       &shellparam.optptr);
505 }
506 
507 STATIC int
508 getopts(char *optstr, char *optvar, char **optfirst, char ***optnext, char **optpptr)
509 {
510 	char *p, *q;
511 	char c = '?';
512 	int done = 0;
513 	int ind = 0;
514 	int err = 0;
515 	char s[12];
516 
517 	if ((p = *optpptr) == NULL || *p == '\0') {
518 		/* Current word is done, advance */
519 		if (*optnext == NULL)
520 			return 1;
521 		p = **optnext;
522 		if (p == NULL || *p != '-' || *++p == '\0') {
523 atend:
524 			ind = *optnext - optfirst + 1;
525 			*optnext = NULL;
526 			p = NULL;
527 			done = 1;
528 			goto out;
529 		}
530 		(*optnext)++;
531 		if (p[0] == '-' && p[1] == '\0')	/* check for "--" */
532 			goto atend;
533 	}
534 
535 	c = *p++;
536 	for (q = optstr; *q != c; ) {
537 		if (*q == '\0') {
538 			if (optstr[0] == ':') {
539 				s[0] = c;
540 				s[1] = '\0';
541 				err |= setvarsafe("OPTARG", s, 0);
542 			} else {
543 				outfmt(&errout, "Illegal option -%c\n", c);
544 				(void) unsetvar("OPTARG", 0);
545 			}
546 			c = '?';
547 			goto bad;
548 		}
549 		if (*++q == ':')
550 			q++;
551 	}
552 
553 	if (*++q == ':') {
554 		if (*p == '\0' && (p = **optnext) == NULL) {
555 			if (optstr[0] == ':') {
556 				s[0] = c;
557 				s[1] = '\0';
558 				err |= setvarsafe("OPTARG", s, 0);
559 				c = ':';
560 			} else {
561 				outfmt(&errout, "No arg for -%c option\n", c);
562 				(void) unsetvar("OPTARG", 0);
563 				c = '?';
564 			}
565 			goto bad;
566 		}
567 
568 		if (p == **optnext)
569 			(*optnext)++;
570 		err |= setvarsafe("OPTARG", p, 0);
571 		p = NULL;
572 	} else
573 		err |= setvarsafe("OPTARG", "", 0);
574 	ind = *optnext - optfirst + 1;
575 	goto out;
576 
577 bad:
578 	ind = 1;
579 	*optnext = NULL;
580 	p = NULL;
581 out:
582 	*optpptr = p;
583 	fmtstr(s, sizeof(s), "%d", ind);
584 	err |= setvarsafe("OPTIND", s, VNOFUNC);
585 	s[0] = c;
586 	s[1] = '\0';
587 	err |= setvarsafe(optvar, s, 0);
588 	if (err) {
589 		*optnext = NULL;
590 		*optpptr = NULL;
591 		flushall();
592 		exraise(EXERROR);
593 	}
594 	return done;
595 }
596 
597 /*
598  * XXX - should get rid of.  have all builtins use getopt(3).  the
599  * library getopt must have the BSD extension static variable "optreset"
600  * otherwise it can't be used within the shell safely.
601  *
602  * Standard option processing (a la getopt) for builtin routines.  The
603  * only argument that is passed to nextopt is the option string; the
604  * other arguments are unnecessary.  It return the character, or '\0' on
605  * end of input.  If optstring is NULL, then there are no options, and
606  * args are allowed to begin with '-', but a single leading "--" will be
607  * discarded.   This is for some POSIX special builtins that require
608  * -- processing, have no args, and we never did opt processing before
609  * and need to retain backwards compat.
610  */
611 
612 int
613 nextopt(const char *optstring)
614 {
615 	char *p;
616 	const char *q;
617 	char c;
618 
619 	if ((p = optptr) == NULL || *p == '\0') {
620 		p = *argptr;
621 		if (p == NULL || *p != '-' || *++p == '\0')
622 			return '\0';
623 		argptr++;
624 		if (p[0] == '-' && p[1] == '\0')	/* check for "--" */
625 			return '\0';
626 		if (optstring == NULL)	/* not processing the "option" */
627 			argptr--;	/* so make it be an arg again */
628 	}
629 	if (optstring == NULL)
630 		return '\0';
631 	c = *p++;
632 	for (q = optstring ; *q != c ; ) {
633 		if (*q == '\0')
634 			error("Illegal option -%c", c);
635 		if (*++q == ':')
636 			q++;
637 	}
638 	if (*++q == ':') {
639 		if (*p == '\0' && (p = *argptr++) == NULL)
640 			error("No arg for -%c option", c);
641 		optionarg = p;
642 		p = NULL;
643 	}
644 	optptr = p;
645 	return c;
646 }
647