xref: /freebsd/bin/sh/options.c (revision 718519f4efc71096422fc71dab90b2a3369871ff)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
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 <signal.h>
36 #include <unistd.h>
37 #include <stdlib.h>
38 
39 #include "shell.h"
40 #define DEFINE_OPTIONS
41 #include "options.h"
42 #undef DEFINE_OPTIONS
43 #include "nodes.h"	/* for other header files */
44 #include "eval.h"
45 #include "jobs.h"
46 #include "input.h"
47 #include "output.h"
48 #include "trap.h"
49 #include "var.h"
50 #include "memalloc.h"
51 #include "error.h"
52 #include "mystring.h"
53 #include "builtins.h"
54 #ifndef NO_HISTORY
55 #include "myhistedit.h"
56 #endif
57 
58 char *arg0;			/* value of $0 */
59 struct shparam shellparam;	/* current positional parameters */
60 char **argptr;			/* argument list for builtin commands */
61 char *shoptarg;			/* set by nextopt (like getopt) */
62 char *nextopt_optptr;		/* used by nextopt */
63 
64 char *minusc;			/* argument to -c option */
65 
66 
67 static int options(int);
68 static void minus_o(char *, int);
69 static void setoption(int, int);
70 static void setoptionbyindex(int, int);
71 static void setparam(int, char **);
72 static int getopts(char *, char *, char **, char ***, char **);
73 
74 
75 /*
76  * Process the shell command line arguments.
77  */
78 
79 int
80 procargs(int argc, char **argv)
81 {
82 	int i, login;
83 	char *scriptname;
84 
85 	argptr = argv;
86 	login = argptr[0] != NULL && argptr[0][0] == '-';
87 	if (argc > 0)
88 		argptr++;
89 	for (i = 0; i < NOPTS; i++)
90 		optval[i] = 2;
91 	privileged = (getuid() != geteuid() || getgid() != getegid());
92 	login |= options(1);
93 	if (*argptr == NULL && minusc == NULL)
94 		sflag = 1;
95 	if (iflag != 0 && sflag == 1 && isatty(0) && isatty(1)) {
96 		iflag = 1;
97 		if (Eflag == 2)
98 			Eflag = 1;
99 	}
100 	if (mflag == 2)
101 		mflag = iflag;
102 	for (i = 0; i < NOPTS; i++)
103 		if (optval[i] == 2)
104 			optval[i] = 0;
105 	arg0 = argv[0];
106 	if (sflag == 0 && minusc == NULL) {
107 		scriptname = *argptr++;
108 		setinputfile(scriptname, 0, -1 /* verify */);
109 		commandname = arg0 = scriptname;
110 	}
111 	/* POSIX 1003.2: first arg after -c cmd is $0, remainder $1... */
112 	if (argptr && minusc && *argptr)
113 		arg0 = *argptr++;
114 
115 	shellparam.p = argptr;
116 	shellparam.reset = 1;
117 	/* assert(shellparam.malloc == 0 && shellparam.nparam == 0); */
118 	while (*argptr) {
119 		shellparam.nparam++;
120 		argptr++;
121 	}
122 	optschanged();
123 
124 	return (login);
125 }
126 
127 
128 void
129 optschanged(void)
130 {
131 	setinteractive();
132 #ifndef NO_HISTORY
133 	histedit();
134 #endif
135 	setjobctl(mflag);
136 }
137 
138 /*
139  * Process shell options.  The global variable argptr contains a pointer
140  * to the argument list; we advance it past the options.
141  * If cmdline is true, process the shell's argv; otherwise, process arguments
142  * to the set special builtin.
143  */
144 
145 static int
146 options(int cmdline)
147 {
148 	char *kp, *p;
149 	int val;
150 	int c;
151 	int login = 0;
152 
153 	if (cmdline)
154 		minusc = NULL;
155 	while ((p = *argptr) != NULL) {
156 		argptr++;
157 		if ((c = *p++) == '-') {
158 			val = 1;
159 			/* A "-" or  "--" terminates options */
160 			if (p[0] == '\0')
161 				goto end_options1;
162 			if (p[0] == '-' && p[1] == '\0')
163 				goto end_options2;
164 			/**
165 			 * For the benefit of `#!' lines in shell scripts,
166 			 * treat a string of '-- *#.*' the same as '--'.
167 			 * This is needed so that a script starting with:
168 			 *	#!/bin/sh -- # -*- perl -*-
169 			 * will continue to work after a change is made to
170 			 * kern/imgact_shell.c to NOT token-ize the options
171 			 * specified on a '#!' line.  A bit of a kludge,
172 			 * but that trick is recommended in documentation
173 			 * for some scripting languages, and we might as
174 			 * well continue to support it.
175 			 */
176 			if (p[0] == '-') {
177 				kp = p + 1;
178 				while (*kp == ' ' || *kp == '\t')
179 					kp++;
180 				if (*kp == '#' || *kp == '\0')
181 					goto end_options2;
182 			}
183 		} else if (c == '+') {
184 			val = 0;
185 		} else {
186 			argptr--;
187 			break;
188 		}
189 		while ((c = *p++) != '\0') {
190 			if (c == 'c' && cmdline) {
191 				char *q;
192 
193 				q = *argptr++;
194 				if (q == NULL || minusc != NULL)
195 					error("Bad -c option");
196 				minusc = q;
197 			} else if (c == 'l' && cmdline) {
198 				login = 1;
199 			} else if (c == 'o') {
200 				minus_o(*argptr, val);
201 				if (*argptr)
202 					argptr++;
203 			} else
204 				setoption(c, val);
205 		}
206 	}
207 	return (login);
208 
209 	/* When processing `set', a single "-" means turn off -x and -v */
210 end_options1:
211 	if (!cmdline) {
212 		xflag = vflag = 0;
213 		return (login);
214 	}
215 
216 	/*
217 	 * When processing `set', a "--" means the remaining arguments
218 	 * replace the positional parameters in the active shell.  If
219 	 * there are no remaining options, then all the positional
220 	 * parameters are cleared (equivalent to doing ``shift $#'').
221 	 */
222 end_options2:
223 	if (!cmdline) {
224 		if (*argptr == NULL)
225 			setparam(0, argptr);
226 		return (login);
227 	}
228 
229 	/*
230 	 * At this point we are processing options given to 'sh' on a command
231 	 * line.  If an end-of-options marker ("-" or "--") is followed by an
232 	 * arg of "#", then skip over all remaining arguments.  Some scripting
233 	 * languages (e.g.: perl) document that /bin/sh will implement this
234 	 * behavior, and they recommend that users take advantage of it to
235 	 * solve certain issues that can come up when writing a perl script.
236 	 * Yes, this feature is in /bin/sh to help users write perl scripts.
237 	 */
238 	p = *argptr;
239 	if (p != NULL && p[0] == '#' && p[1] == '\0') {
240 		while (*argptr != NULL)
241 			argptr++;
242 		/* We need to keep the final argument */
243 		argptr--;
244 	}
245 
246 	return (login);
247 }
248 
249 static void
250 minus_o(char *name, int val)
251 {
252 	int i;
253 	const unsigned char *on;
254 	size_t len;
255 
256 	if (name == NULL) {
257 		if (val) {
258 			/* "Pretty" output. */
259 			out1str("Current option settings\n");
260 			for (i = 0, on = optname; i < NOPTS; i++, on += *on + 1)
261 				out1fmt("%-16.*s%s\n", *on, on + 1,
262 					optval[i] ? "on" : "off");
263 		} else {
264 			/* Output suitable for re-input to shell. */
265 			for (i = 0, on = optname; i < NOPTS; i++, on += *on + 1)
266 				out1fmt("%s %co %.*s%s",
267 				    i % 6 == 0 ? "set" : "",
268 				    optval[i] ? '-' : '+',
269 				    *on, on + 1,
270 				    i % 6 == 5 || i == NOPTS - 1 ? "\n" : "");
271 		}
272 	} else {
273 		len = strlen(name);
274 		for (i = 0, on = optname; i < NOPTS; i++, on += *on + 1)
275 			if (*on == len && memcmp(on + 1, name, len) == 0) {
276 				setoptionbyindex(i, val);
277 				return;
278 			}
279 		error("Illegal option -o %s", name);
280 	}
281 }
282 
283 
284 static void
285 setoptionbyindex(int idx, int val)
286 {
287 	if (&optval[idx] == &privileged && !val && privileged) {
288 		if (setgid(getgid()) == -1)
289 			error("setgid");
290 		if (setuid(getuid()) == -1)
291 			error("setuid");
292 	}
293 	optval[idx] = val;
294 	if (val) {
295 		/* #%$ hack for ksh semantics */
296 		if (&optval[idx] == &Vflag)
297 			Eflag = 0;
298 		else if (&optval[idx] == &Eflag)
299 			Vflag = 0;
300 	}
301 }
302 
303 static void
304 setoption(int flag, int val)
305 {
306 	int i;
307 
308 	for (i = 0; i < NSHORTOPTS; i++)
309 		if (optletter[i] == flag) {
310 			setoptionbyindex(i, val);
311 			return;
312 		}
313 	error("Illegal option -%c", flag);
314 }
315 
316 
317 /*
318  * Set the shell parameters.
319  */
320 
321 static void
322 setparam(int argc, char **argv)
323 {
324 	char **newparam;
325 	char **ap;
326 
327 	ap = newparam = ckmalloc((argc + 1) * sizeof *ap);
328 	while (*argv) {
329 		*ap++ = savestr(*argv++);
330 	}
331 	*ap = NULL;
332 	freeparam(&shellparam);
333 	shellparam.malloc = 1;
334 	shellparam.nparam = argc;
335 	shellparam.p = newparam;
336 	shellparam.optp = NULL;
337 	shellparam.reset = 1;
338 	shellparam.optnext = NULL;
339 }
340 
341 
342 /*
343  * Free the list of positional parameters.
344  */
345 
346 void
347 freeparam(struct shparam *param)
348 {
349 	char **ap;
350 
351 	if (param->malloc) {
352 		for (ap = param->p ; *ap ; ap++)
353 			ckfree(*ap);
354 		ckfree(param->p);
355 	}
356 	if (param->optp) {
357 		for (ap = param->optp ; *ap ; ap++)
358 			ckfree(*ap);
359 		ckfree(param->optp);
360 	}
361 }
362 
363 
364 
365 /*
366  * The shift builtin command.
367  */
368 
369 int
370 shiftcmd(int argc, char **argv)
371 {
372 	int i, n;
373 
374 	n = 1;
375 	if (argc > 1)
376 		n = number(argv[1]);
377 	if (n > shellparam.nparam)
378 		return 1;
379 	INTOFF;
380 	shellparam.nparam -= n;
381 	if (shellparam.malloc)
382 		for (i = 0; i < n; i++)
383 			ckfree(shellparam.p[i]);
384 	memmove(shellparam.p, shellparam.p + n,
385 	    (shellparam.nparam + 1) * sizeof(shellparam.p[0]));
386 	shellparam.reset = 1;
387 	INTON;
388 	return 0;
389 }
390 
391 
392 
393 /*
394  * The set builtin command.
395  */
396 
397 int
398 setcmd(int argc, char **argv)
399 {
400 	if (argc == 1)
401 		return showvarscmd(argc, argv);
402 	INTOFF;
403 	options(0);
404 	optschanged();
405 	if (*argptr != NULL) {
406 		setparam(argc - (argptr - argv), argptr);
407 	}
408 	INTON;
409 	return 0;
410 }
411 
412 
413 void
414 getoptsreset(const char *value)
415 {
416 	while (*value == '0')
417 		value++;
418 	if (strcmp(value, "1") == 0)
419 		shellparam.reset = 1;
420 }
421 
422 /*
423  * The getopts builtin.  Shellparam.optnext points to the next argument
424  * to be processed.  Shellparam.optptr points to the next character to
425  * be processed in the current argument.  If shellparam.optnext is NULL,
426  * then it's the first time getopts has been called.
427  */
428 
429 int
430 getoptscmd(int argc, char **argv)
431 {
432 	char **optbase = NULL, **ap;
433 	int i;
434 
435 	if (argc < 3)
436 		error("usage: getopts optstring var [arg]");
437 
438 	if (shellparam.reset == 1) {
439 		INTOFF;
440 		if (shellparam.optp) {
441 			for (ap = shellparam.optp ; *ap ; ap++)
442 				ckfree(*ap);
443 			ckfree(shellparam.optp);
444 			shellparam.optp = NULL;
445 		}
446 		if (argc > 3) {
447 			shellparam.optp = ckmalloc((argc - 2) * sizeof *ap);
448 			memset(shellparam.optp, '\0', (argc - 2) * sizeof *ap);
449 			for (i = 0; i < argc - 3; i++)
450 				shellparam.optp[i] = savestr(argv[i + 3]);
451 		}
452 		INTON;
453 		optbase = argc == 3 ? shellparam.p : shellparam.optp;
454 		shellparam.optnext = optbase;
455 		shellparam.optptr = NULL;
456 		shellparam.reset = 0;
457 	} else
458 		optbase = shellparam.optp ? shellparam.optp : shellparam.p;
459 
460 	return getopts(argv[1], argv[2], optbase, &shellparam.optnext,
461 		       &shellparam.optptr);
462 }
463 
464 static int
465 getopts(char *optstr, char *optvar, char **optfirst, char ***optnext,
466     char **optptr)
467 {
468 	char *p, *q;
469 	char c = '?';
470 	int done = 0;
471 	int ind = 0;
472 	int err = 0;
473 	char s[10];
474 	const char *newoptarg = NULL;
475 
476 	if ((p = *optptr) == NULL || *p == '\0') {
477 		/* Current word is done, advance */
478 		if (*optnext == NULL)
479 			return 1;
480 		p = **optnext;
481 		if (p == NULL || *p != '-' || *++p == '\0') {
482 atend:
483 			ind = *optnext - optfirst + 1;
484 			*optnext = NULL;
485 			p = NULL;
486 			done = 1;
487 			goto out;
488 		}
489 		(*optnext)++;
490 		if (p[0] == '-' && p[1] == '\0')	/* check for "--" */
491 			goto atend;
492 	}
493 
494 	c = *p++;
495 	for (q = optstr; *q != c; ) {
496 		if (*q == '\0') {
497 			if (optstr[0] == ':') {
498 				s[0] = c;
499 				s[1] = '\0';
500 				newoptarg = s;
501 			}
502 			else
503 				out2fmt_flush("Illegal option -%c\n", c);
504 			c = '?';
505 			goto out;
506 		}
507 		if (*++q == ':')
508 			q++;
509 	}
510 
511 	if (*++q == ':') {
512 		if (*p == '\0' && (p = **optnext) == NULL) {
513 			if (optstr[0] == ':') {
514 				s[0] = c;
515 				s[1] = '\0';
516 				newoptarg = s;
517 				c = ':';
518 			}
519 			else {
520 				out2fmt_flush("No arg for -%c option\n", c);
521 				c = '?';
522 			}
523 			goto out;
524 		}
525 
526 		if (p == **optnext)
527 			(*optnext)++;
528 		newoptarg = p;
529 		p = NULL;
530 	}
531 
532 out:
533 	if (*optnext != NULL)
534 		ind = *optnext - optfirst + 1;
535 	*optptr = p;
536 	if (newoptarg != NULL)
537 		err |= setvarsafe("OPTARG", newoptarg, 0);
538 	else {
539 		INTOFF;
540 		err |= unsetvar("OPTARG");
541 		INTON;
542 	}
543 	fmtstr(s, sizeof(s), "%d", ind);
544 	err |= setvarsafe("OPTIND", s, VNOFUNC);
545 	s[0] = c;
546 	s[1] = '\0';
547 	err |= setvarsafe(optvar, s, 0);
548 	if (err) {
549 		*optnext = NULL;
550 		*optptr = NULL;
551 		flushall();
552 		exraise(EXERROR);
553 	}
554 	return done;
555 }
556 
557 /*
558  * Standard option processing (a la getopt) for builtin routines.  The
559  * only argument that is passed to nextopt is the option string; the
560  * other arguments are unnecessary.  It returns the option, or '\0' on
561  * end of input.
562  */
563 
564 int
565 nextopt(const char *optstring)
566 {
567 	char *p;
568 	const char *q;
569 	char c;
570 
571 	if ((p = nextopt_optptr) == NULL || *p == '\0') {
572 		p = *argptr;
573 		if (p == NULL || *p != '-' || *++p == '\0')
574 			return '\0';
575 		argptr++;
576 		if (p[0] == '-' && p[1] == '\0')	/* check for "--" */
577 			return '\0';
578 	}
579 	c = *p++;
580 	for (q = optstring ; *q != c ; ) {
581 		if (*q == '\0')
582 			error("Illegal option -%c", c);
583 		if (*++q == ':')
584 			q++;
585 	}
586 	if (*++q == ':') {
587 		if (*p == '\0' && (p = *argptr++) == NULL)
588 			error("No arg for -%c option", c);
589 		shoptarg = p;
590 		p = NULL;
591 	}
592 	if (p != NULL && *p != '\0')
593 		nextopt_optptr = p;
594 	else
595 		nextopt_optptr = NULL;
596 	return c;
597 }
598