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options.c revision 1.16
      1  1.16  christos /*	$NetBSD: options.c,v 1.16 1996/06/25 16:47:43 christos Exp $	*/
      2  1.11       cgd 
      3   1.1       cgd /*-
      4   1.5       jtc  * Copyright (c) 1991, 1993
      5   1.5       jtc  *	The Regents of the University of California.  All rights reserved.
      6   1.1       cgd  *
      7   1.1       cgd  * This code is derived from software contributed to Berkeley by
      8   1.1       cgd  * Kenneth Almquist.
      9   1.1       cgd  *
     10   1.1       cgd  * Redistribution and use in source and binary forms, with or without
     11   1.1       cgd  * modification, are permitted provided that the following conditions
     12   1.1       cgd  * are met:
     13   1.1       cgd  * 1. Redistributions of source code must retain the above copyright
     14   1.1       cgd  *    notice, this list of conditions and the following disclaimer.
     15   1.1       cgd  * 2. Redistributions in binary form must reproduce the above copyright
     16   1.1       cgd  *    notice, this list of conditions and the following disclaimer in the
     17   1.1       cgd  *    documentation and/or other materials provided with the distribution.
     18   1.1       cgd  * 3. All advertising materials mentioning features or use of this software
     19   1.1       cgd  *    must display the following acknowledgement:
     20   1.1       cgd  *	This product includes software developed by the University of
     21   1.1       cgd  *	California, Berkeley and its contributors.
     22   1.1       cgd  * 4. Neither the name of the University nor the names of its contributors
     23   1.1       cgd  *    may be used to endorse or promote products derived from this software
     24   1.1       cgd  *    without specific prior written permission.
     25   1.1       cgd  *
     26   1.1       cgd  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     27   1.1       cgd  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     28   1.1       cgd  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     29   1.1       cgd  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     30   1.1       cgd  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     31   1.1       cgd  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     32   1.1       cgd  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     33   1.1       cgd  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     34   1.1       cgd  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     35   1.1       cgd  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     36   1.1       cgd  * SUCH DAMAGE.
     37   1.1       cgd  */
     38   1.1       cgd 
     39   1.1       cgd #ifndef lint
     40  1.11       cgd #if 0
     41  1.14  christos static char sccsid[] = "@(#)options.c	8.2 (Berkeley) 5/4/95";
     42  1.11       cgd #else
     43  1.16  christos static char rcsid[] = "$NetBSD: options.c,v 1.16 1996/06/25 16:47:43 christos Exp $";
     44  1.11       cgd #endif
     45   1.1       cgd #endif /* not lint */
     46   1.1       cgd 
     47  1.14  christos #include <signal.h>
     48  1.14  christos #include <unistd.h>
     49  1.14  christos #include <stdlib.h>
     50  1.14  christos 
     51   1.1       cgd #include "shell.h"
     52   1.1       cgd #define DEFINE_OPTIONS
     53   1.1       cgd #include "options.h"
     54   1.1       cgd #undef DEFINE_OPTIONS
     55   1.1       cgd #include "nodes.h"	/* for other header files */
     56   1.1       cgd #include "eval.h"
     57   1.1       cgd #include "jobs.h"
     58   1.1       cgd #include "input.h"
     59   1.1       cgd #include "output.h"
     60   1.1       cgd #include "trap.h"
     61   1.1       cgd #include "var.h"
     62   1.1       cgd #include "memalloc.h"
     63   1.1       cgd #include "error.h"
     64   1.1       cgd #include "mystring.h"
     65  1.14  christos #ifndef NO_HISTORY
     66  1.14  christos #include "myhistedit.h"
     67  1.14  christos #endif
     68   1.1       cgd 
     69   1.1       cgd char *arg0;			/* value of $0 */
     70   1.1       cgd struct shparam shellparam;	/* current positional parameters */
     71   1.1       cgd char **argptr;			/* argument list for builtin commands */
     72   1.1       cgd char *optarg;			/* set by nextopt (like getopt) */
     73   1.1       cgd char *optptr;			/* used by nextopt */
     74   1.1       cgd 
     75   1.1       cgd char *minusc;			/* argument to -c option */
     76   1.1       cgd 
     77   1.1       cgd 
     78  1.14  christos STATIC void options __P((int));
     79  1.14  christos STATIC void minus_o __P((char *, int));
     80  1.14  christos STATIC void setoption __P((int, int));
     81  1.15  christos STATIC int getopts __P((char *, char *, char **, char ***, char **));
     82   1.1       cgd 
     83   1.1       cgd 
     84   1.1       cgd /*
     85   1.1       cgd  * Process the shell command line arguments.
     86   1.1       cgd  */
     87   1.1       cgd 
     88   1.1       cgd void
     89   1.1       cgd procargs(argc, argv)
     90  1.10       cgd 	int argc;
     91   1.1       cgd 	char **argv;
     92  1.10       cgd {
     93   1.5       jtc 	int i;
     94   1.1       cgd 
     95   1.1       cgd 	argptr = argv;
     96   1.1       cgd 	if (argc > 0)
     97   1.1       cgd 		argptr++;
     98   1.5       jtc 	for (i = 0; i < NOPTS; i++)
     99   1.5       jtc 		optlist[i].val = 2;
    100   1.1       cgd 	options(1);
    101   1.1       cgd 	if (*argptr == NULL && minusc == NULL)
    102   1.1       cgd 		sflag = 1;
    103   1.1       cgd 	if (iflag == 2 && sflag == 1 && isatty(0) && isatty(1))
    104   1.1       cgd 		iflag = 1;
    105   1.5       jtc 	if (mflag == 2)
    106   1.5       jtc 		mflag = iflag;
    107   1.5       jtc 	for (i = 0; i < NOPTS; i++)
    108   1.5       jtc 		if (optlist[i].val == 2)
    109   1.5       jtc 			optlist[i].val = 0;
    110   1.1       cgd 	arg0 = argv[0];
    111   1.1       cgd 	if (sflag == 0 && minusc == NULL) {
    112   1.1       cgd 		commandname = arg0 = *argptr++;
    113   1.1       cgd 		setinputfile(commandname, 0);
    114   1.1       cgd 	}
    115   1.1       cgd 	shellparam.p = argptr;
    116   1.1       cgd 	/* assert(shellparam.malloc == 0 && shellparam.nparam == 0); */
    117   1.1       cgd 	while (*argptr) {
    118   1.1       cgd 		shellparam.nparam++;
    119   1.1       cgd 		argptr++;
    120   1.1       cgd 	}
    121   1.5       jtc 	optschanged();
    122   1.1       cgd }
    123   1.1       cgd 
    124   1.1       cgd 
    125   1.9       cgd void
    126   1.9       cgd optschanged()
    127   1.9       cgd {
    128   1.5       jtc 	setinteractive(iflag);
    129   1.7       cgd #ifndef NO_HISTORY
    130   1.5       jtc 	histedit();
    131   1.7       cgd #endif
    132   1.5       jtc 	setjobctl(mflag);
    133   1.5       jtc }
    134   1.1       cgd 
    135   1.1       cgd /*
    136   1.1       cgd  * Process shell options.  The global variable argptr contains a pointer
    137   1.1       cgd  * to the argument list; we advance it past the options.
    138   1.1       cgd  */
    139   1.1       cgd 
    140   1.1       cgd STATIC void
    141  1.10       cgd options(cmdline)
    142  1.10       cgd 	int cmdline;
    143  1.10       cgd {
    144   1.1       cgd 	register char *p;
    145   1.1       cgd 	int val;
    146   1.1       cgd 	int c;
    147   1.1       cgd 
    148   1.1       cgd 	if (cmdline)
    149   1.1       cgd 		minusc = NULL;
    150   1.1       cgd 	while ((p = *argptr) != NULL) {
    151   1.1       cgd 		argptr++;
    152   1.1       cgd 		if ((c = *p++) == '-') {
    153   1.1       cgd 			val = 1;
    154  1.14  christos                         if (p[0] == '\0' || (p[0] == '-' && p[1] == '\0')) {
    155   1.1       cgd                                 if (!cmdline) {
    156   1.1       cgd                                         /* "-" means turn off -x and -v */
    157   1.1       cgd                                         if (p[0] == '\0')
    158   1.1       cgd                                                 xflag = vflag = 0;
    159   1.1       cgd                                         /* "--" means reset params */
    160  1.13  christos                                         else if (*argptr == NULL)
    161  1.13  christos 						setparam(argptr);
    162   1.1       cgd                                 }
    163   1.1       cgd 				break;	  /* "-" or  "--" terminates options */
    164   1.1       cgd 			}
    165   1.1       cgd 		} else if (c == '+') {
    166   1.1       cgd 			val = 0;
    167   1.1       cgd 		} else {
    168   1.1       cgd 			argptr--;
    169   1.1       cgd 			break;
    170   1.1       cgd 		}
    171   1.1       cgd 		while ((c = *p++) != '\0') {
    172   1.1       cgd 			if (c == 'c' && cmdline) {
    173   1.1       cgd 				char *q;
    174   1.1       cgd #ifdef NOHACK	/* removing this code allows sh -ce 'foo' for compat */
    175   1.1       cgd 				if (*p == '\0')
    176   1.1       cgd #endif
    177   1.1       cgd 					q = *argptr++;
    178   1.1       cgd 				if (q == NULL || minusc != NULL)
    179   1.1       cgd 					error("Bad -c option");
    180   1.1       cgd 				minusc = q;
    181   1.1       cgd #ifdef NOHACK
    182   1.1       cgd 				break;
    183   1.1       cgd #endif
    184   1.5       jtc 			} else if (c == 'o') {
    185   1.5       jtc 				minus_o(*argptr, val);
    186   1.5       jtc 				if (*argptr)
    187   1.5       jtc 					argptr++;
    188   1.1       cgd 			} else {
    189   1.1       cgd 				setoption(c, val);
    190   1.1       cgd 			}
    191   1.1       cgd 		}
    192   1.1       cgd 	}
    193   1.1       cgd }
    194   1.1       cgd 
    195   1.5       jtc STATIC void
    196   1.5       jtc minus_o(name, val)
    197   1.5       jtc 	char *name;
    198   1.5       jtc 	int val;
    199   1.5       jtc {
    200   1.5       jtc 	int i;
    201   1.5       jtc 
    202   1.5       jtc 	if (name == NULL) {
    203   1.5       jtc 		out1str("Current option settings\n");
    204   1.5       jtc 		for (i = 0; i < NOPTS; i++)
    205   1.5       jtc 			out1fmt("%-16s%s\n", optlist[i].name,
    206   1.5       jtc 				optlist[i].val ? "on" : "off");
    207   1.5       jtc 	} else {
    208   1.5       jtc 		for (i = 0; i < NOPTS; i++)
    209   1.5       jtc 			if (equal(name, optlist[i].name)) {
    210   1.5       jtc 				setoption(optlist[i].letter, val);
    211   1.5       jtc 				return;
    212   1.5       jtc 			}
    213   1.5       jtc 		error("Illegal option -o %s", name);
    214   1.5       jtc 	}
    215   1.5       jtc }
    216   1.5       jtc 
    217   1.1       cgd 
    218   1.1       cgd STATIC void
    219   1.1       cgd setoption(flag, val)
    220   1.1       cgd 	char flag;
    221   1.1       cgd 	int val;
    222   1.1       cgd 	{
    223   1.5       jtc 	int i;
    224   1.1       cgd 
    225   1.5       jtc 	for (i = 0; i < NOPTS; i++)
    226   1.5       jtc 		if (optlist[i].letter == flag) {
    227   1.5       jtc 			optlist[i].val = val;
    228   1.5       jtc 			if (val) {
    229   1.5       jtc 				/* #%$ hack for ksh semantics */
    230   1.5       jtc 				if (flag == 'V')
    231   1.5       jtc 					Eflag = 0;
    232   1.5       jtc 				else if (flag == 'E')
    233   1.5       jtc 					Vflag = 0;
    234   1.5       jtc 			}
    235   1.5       jtc 			return;
    236   1.5       jtc 		}
    237   1.5       jtc 	error("Illegal option -%c", flag);
    238   1.1       cgd }
    239   1.1       cgd 
    240   1.1       cgd 
    241   1.1       cgd 
    242   1.1       cgd #ifdef mkinit
    243   1.1       cgd INCLUDE "options.h"
    244   1.1       cgd 
    245   1.1       cgd SHELLPROC {
    246   1.5       jtc 	int i;
    247   1.5       jtc 
    248   1.5       jtc 	for (i = 0; i < NOPTS; i++)
    249   1.5       jtc 		optlist[i].val = 0;
    250   1.5       jtc 	optschanged();
    251   1.1       cgd 
    252   1.1       cgd }
    253   1.1       cgd #endif
    254   1.1       cgd 
    255   1.1       cgd 
    256   1.1       cgd /*
    257   1.1       cgd  * Set the shell parameters.
    258   1.1       cgd  */
    259   1.1       cgd 
    260   1.1       cgd void
    261   1.1       cgd setparam(argv)
    262   1.1       cgd 	char **argv;
    263   1.1       cgd 	{
    264   1.1       cgd 	char **newparam;
    265   1.1       cgd 	char **ap;
    266   1.1       cgd 	int nparam;
    267   1.1       cgd 
    268   1.1       cgd 	for (nparam = 0 ; argv[nparam] ; nparam++);
    269   1.1       cgd 	ap = newparam = ckmalloc((nparam + 1) * sizeof *ap);
    270   1.1       cgd 	while (*argv) {
    271   1.1       cgd 		*ap++ = savestr(*argv++);
    272   1.1       cgd 	}
    273   1.1       cgd 	*ap = NULL;
    274   1.1       cgd 	freeparam(&shellparam);
    275   1.1       cgd 	shellparam.malloc = 1;
    276   1.1       cgd 	shellparam.nparam = nparam;
    277   1.1       cgd 	shellparam.p = newparam;
    278   1.1       cgd 	shellparam.optnext = NULL;
    279   1.1       cgd }
    280   1.1       cgd 
    281   1.1       cgd 
    282   1.1       cgd /*
    283   1.1       cgd  * Free the list of positional parameters.
    284   1.1       cgd  */
    285   1.1       cgd 
    286   1.1       cgd void
    287   1.1       cgd freeparam(param)
    288   1.1       cgd 	struct shparam *param;
    289   1.1       cgd 	{
    290   1.1       cgd 	char **ap;
    291   1.1       cgd 
    292   1.1       cgd 	if (param->malloc) {
    293   1.1       cgd 		for (ap = param->p ; *ap ; ap++)
    294   1.1       cgd 			ckfree(*ap);
    295   1.1       cgd 		ckfree(param->p);
    296   1.1       cgd 	}
    297   1.1       cgd }
    298   1.1       cgd 
    299   1.1       cgd 
    300   1.1       cgd 
    301   1.1       cgd /*
    302   1.1       cgd  * The shift builtin command.
    303   1.1       cgd  */
    304   1.1       cgd 
    305  1.10       cgd int
    306  1.10       cgd shiftcmd(argc, argv)
    307  1.10       cgd 	int argc;
    308  1.10       cgd 	char **argv;
    309  1.10       cgd {
    310   1.1       cgd 	int n;
    311   1.1       cgd 	char **ap1, **ap2;
    312   1.1       cgd 
    313   1.1       cgd 	n = 1;
    314   1.1       cgd 	if (argc > 1)
    315   1.1       cgd 		n = number(argv[1]);
    316   1.1       cgd 	if (n > shellparam.nparam)
    317   1.5       jtc 		error("can't shift that many");
    318   1.1       cgd 	INTOFF;
    319   1.1       cgd 	shellparam.nparam -= n;
    320   1.1       cgd 	for (ap1 = shellparam.p ; --n >= 0 ; ap1++) {
    321   1.1       cgd 		if (shellparam.malloc)
    322   1.1       cgd 			ckfree(*ap1);
    323   1.1       cgd 	}
    324   1.1       cgd 	ap2 = shellparam.p;
    325   1.1       cgd 	while ((*ap2++ = *ap1++) != NULL);
    326   1.1       cgd 	shellparam.optnext = NULL;
    327   1.1       cgd 	INTON;
    328   1.1       cgd 	return 0;
    329   1.1       cgd }
    330   1.1       cgd 
    331   1.1       cgd 
    332   1.1       cgd 
    333   1.1       cgd /*
    334   1.1       cgd  * The set command builtin.
    335   1.1       cgd  */
    336   1.1       cgd 
    337  1.10       cgd int
    338  1.10       cgd setcmd(argc, argv)
    339  1.10       cgd 	int argc;
    340  1.10       cgd 	char **argv;
    341  1.10       cgd {
    342   1.1       cgd 	if (argc == 1)
    343   1.1       cgd 		return showvarscmd(argc, argv);
    344   1.1       cgd 	INTOFF;
    345   1.1       cgd 	options(0);
    346   1.5       jtc 	optschanged();
    347   1.1       cgd 	if (*argptr != NULL) {
    348   1.1       cgd 		setparam(argptr);
    349   1.1       cgd 	}
    350   1.1       cgd 	INTON;
    351   1.1       cgd 	return 0;
    352   1.1       cgd }
    353   1.1       cgd 
    354   1.1       cgd 
    355  1.16  christos void
    356  1.16  christos getoptsreset(value)
    357  1.16  christos 	const char *value;
    358  1.16  christos {
    359  1.16  christos 	if (number(value) == 1)
    360  1.16  christos 		shellparam.optnext;
    361  1.16  christos }
    362  1.16  christos 
    363   1.1       cgd /*
    364   1.1       cgd  * The getopts builtin.  Shellparam.optnext points to the next argument
    365   1.1       cgd  * to be processed.  Shellparam.optptr points to the next character to
    366   1.1       cgd  * be processed in the current argument.  If shellparam.optnext is NULL,
    367   1.1       cgd  * then it's the first time getopts has been called.
    368   1.1       cgd  */
    369   1.1       cgd 
    370  1.10       cgd int
    371  1.10       cgd getoptscmd(argc, argv)
    372  1.10       cgd 	int argc;
    373  1.10       cgd 	char **argv;
    374  1.10       cgd {
    375  1.15  christos 	char **optbase;
    376  1.15  christos 
    377  1.15  christos 	if (argc < 3)
    378  1.15  christos 		error("Usage: getopts optstring var [arg]");
    379  1.15  christos 	else if (argc == 3)
    380  1.15  christos 		optbase = shellparam.p;
    381  1.15  christos 	else
    382  1.15  christos 		optbase = &argv[3];
    383   1.1       cgd 
    384   1.1       cgd 	if (shellparam.optnext == NULL) {
    385  1.15  christos 		shellparam.optnext = optbase;
    386   1.1       cgd 		shellparam.optptr = NULL;
    387   1.1       cgd 	}
    388  1.15  christos 
    389  1.15  christos 	return getopts(argv[1], argv[2], optbase, &shellparam.optnext,
    390  1.15  christos 		       &shellparam.optptr);
    391  1.15  christos }
    392  1.15  christos 
    393  1.15  christos STATIC int
    394  1.15  christos getopts(optstr, optvar, optfirst, optnext, optptr)
    395  1.15  christos 	char *optstr;
    396  1.15  christos 	char *optvar;
    397  1.15  christos 	char **optfirst;
    398  1.15  christos 	char ***optnext;
    399  1.15  christos 	char **optptr;
    400  1.15  christos {
    401  1.15  christos 	register char *p, *q;
    402  1.15  christos 	char c = '?';
    403  1.15  christos 	int done = 0;
    404  1.15  christos 	int ind = 0;
    405  1.16  christos 	int err = 0;
    406  1.15  christos 	char s[10];
    407  1.15  christos 
    408  1.15  christos 	if ((p = *optptr) == NULL || *p == '\0') {
    409  1.15  christos 		/* Current word is done, advance */
    410  1.15  christos 		p = **optnext;
    411   1.1       cgd 		if (p == NULL || *p != '-' || *++p == '\0') {
    412   1.1       cgd atend:
    413  1.15  christos 			**optnext = NULL;
    414  1.15  christos 			ind = *optnext - optfirst + 1;
    415  1.15  christos 			done = 1;
    416  1.15  christos 			goto out;
    417   1.1       cgd 		}
    418  1.15  christos 		(*optnext)++;
    419   1.1       cgd 		if (p[0] == '-' && p[1] == '\0')	/* check for "--" */
    420   1.1       cgd 			goto atend;
    421   1.1       cgd 	}
    422  1.15  christos 
    423   1.1       cgd 	c = *p++;
    424  1.15  christos 	for (q = optstr; *q != c; ) {
    425   1.1       cgd 		if (*q == '\0') {
    426  1.15  christos 			if (optstr[0] == ':') {
    427  1.15  christos 				s[0] = c;
    428  1.15  christos 				s[1] = '\0';
    429  1.16  christos 				err |= setvarsafe("OPTARG", s, 0);
    430  1.15  christos 			}
    431  1.15  christos 			else {
    432  1.15  christos 				out1fmt("Illegal option -%c\n", c);
    433  1.16  christos 				(void) unsetvar("OPTARG");
    434  1.15  christos 			}
    435   1.1       cgd 			c = '?';
    436  1.16  christos 			goto bad;
    437   1.1       cgd 		}
    438   1.1       cgd 		if (*++q == ':')
    439   1.1       cgd 			q++;
    440   1.1       cgd 	}
    441  1.15  christos 
    442   1.1       cgd 	if (*++q == ':') {
    443  1.15  christos 		if (*p == '\0' && (p = **optnext) == NULL) {
    444  1.15  christos 			if (optstr[0] == ':') {
    445  1.15  christos 				s[0] = c;
    446  1.15  christos 				s[1] = '\0';
    447  1.16  christos 				err |= setvarsafe("OPTARG", s, 0);
    448  1.15  christos 				c = ':';
    449  1.15  christos 			}
    450  1.15  christos 			else {
    451  1.15  christos 				out1fmt("No arg for -%c option\n", c);
    452  1.16  christos 				(void) unsetvar("OPTARG");
    453  1.15  christos 				c = '?';
    454  1.15  christos 			}
    455  1.16  christos 			ind = 1;
    456  1.16  christos 			*optnext = NULL;
    457  1.16  christos 			goto bad;
    458   1.1       cgd 		}
    459  1.15  christos 
    460  1.15  christos 		if (p == **optnext)
    461  1.15  christos 			(*optnext)++;
    462  1.15  christos 		ind = *optnext - optfirst + 1;
    463  1.16  christos 		setvarsafe("OPTARG", p, 0);
    464   1.1       cgd 		p = NULL;
    465  1.16  christos 		goto out;
    466   1.1       cgd 	}
    467  1.16  christos bad:
    468  1.16  christos 	ind = 1;
    469  1.16  christos 	*optnext = NULL;
    470  1.16  christos 	p = NULL;
    471   1.1       cgd out:
    472  1.15  christos 	*optptr = p;
    473  1.15  christos 	fmtstr(s, sizeof(s), "%d", ind);
    474  1.16  christos 	err |= setvarsafe("OPTIND", s, VNOFUNC);
    475   1.1       cgd 	s[0] = c;
    476   1.1       cgd 	s[1] = '\0';
    477  1.16  christos 	err |= setvarsafe(optvar, s, 0);
    478  1.16  christos 	if (err) {
    479  1.16  christos 		*optnext = NULL;
    480  1.16  christos 		*optptr = NULL;
    481  1.16  christos 		flushall();
    482  1.16  christos 		exraise(EXERROR);
    483  1.16  christos 	}
    484  1.15  christos 	return done;
    485   1.1       cgd }
    486   1.1       cgd 
    487   1.1       cgd /*
    488   1.5       jtc  * XXX - should get rid of.  have all builtins use getopt(3).  the
    489   1.5       jtc  * library getopt must have the BSD extension static variable "optreset"
    490   1.5       jtc  * otherwise it can't be used within the shell safely.
    491   1.5       jtc  *
    492   1.1       cgd  * Standard option processing (a la getopt) for builtin routines.  The
    493   1.1       cgd  * only argument that is passed to nextopt is the option string; the
    494   1.1       cgd  * other arguments are unnecessary.  It return the character, or '\0' on
    495   1.1       cgd  * end of input.
    496   1.1       cgd  */
    497   1.1       cgd 
    498   1.1       cgd int
    499   1.1       cgd nextopt(optstring)
    500   1.1       cgd 	char *optstring;
    501   1.1       cgd 	{
    502   1.1       cgd 	register char *p, *q;
    503   1.1       cgd 	char c;
    504   1.1       cgd 
    505   1.1       cgd 	if ((p = optptr) == NULL || *p == '\0') {
    506   1.1       cgd 		p = *argptr;
    507   1.1       cgd 		if (p == NULL || *p != '-' || *++p == '\0')
    508   1.1       cgd 			return '\0';
    509   1.1       cgd 		argptr++;
    510   1.1       cgd 		if (p[0] == '-' && p[1] == '\0')	/* check for "--" */
    511   1.1       cgd 			return '\0';
    512   1.1       cgd 	}
    513   1.1       cgd 	c = *p++;
    514   1.1       cgd 	for (q = optstring ; *q != c ; ) {
    515   1.1       cgd 		if (*q == '\0')
    516   1.1       cgd 			error("Illegal option -%c", c);
    517   1.1       cgd 		if (*++q == ':')
    518   1.1       cgd 			q++;
    519   1.1       cgd 	}
    520   1.1       cgd 	if (*++q == ':') {
    521   1.1       cgd 		if (*p == '\0' && (p = *argptr++) == NULL)
    522   1.1       cgd 			error("No arg for -%c option", c);
    523   1.1       cgd 		optarg = p;
    524   1.1       cgd 		p = NULL;
    525   1.1       cgd 	}
    526   1.1       cgd 	optptr = p;
    527   1.1       cgd 	return c;
    528   1.1       cgd }
    529