options.c revision 151866
11556Srgrimes/*- 21556Srgrimes * Copyright (c) 1991, 1993 31556Srgrimes * The Regents of the University of California. All rights reserved. 41556Srgrimes * 51556Srgrimes * This code is derived from software contributed to Berkeley by 61556Srgrimes * Kenneth Almquist. 71556Srgrimes * 81556Srgrimes * Redistribution and use in source and binary forms, with or without 91556Srgrimes * modification, are permitted provided that the following conditions 101556Srgrimes * are met: 111556Srgrimes * 1. Redistributions of source code must retain the above copyright 121556Srgrimes * notice, this list of conditions and the following disclaimer. 131556Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 141556Srgrimes * notice, this list of conditions and the following disclaimer in the 151556Srgrimes * documentation and/or other materials provided with the distribution. 161556Srgrimes * 4. Neither the name of the University nor the names of its contributors 171556Srgrimes * may be used to endorse or promote products derived from this software 181556Srgrimes * without specific prior written permission. 191556Srgrimes * 201556Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 211556Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 221556Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 231556Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 241556Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 251556Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 261556Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 271556Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 281556Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 291556Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 301556Srgrimes * SUCH DAMAGE. 311556Srgrimes */ 321556Srgrimes 331556Srgrimes#ifndef lint 3436150Scharnier#if 0 3536150Scharnierstatic char sccsid[] = "@(#)options.c 8.2 (Berkeley) 5/4/95"; 3636150Scharnier#endif 371556Srgrimes#endif /* not lint */ 3899110Sobrien#include <sys/cdefs.h> 3999110Sobrien__FBSDID("$FreeBSD: head/bin/sh/options.c 151866 2005-10-29 18:41:35Z stefanf $"); 401556Srgrimes 4117987Speter#include <signal.h> 4217987Speter#include <unistd.h> 4317987Speter#include <stdlib.h> 4417987Speter 451556Srgrimes#include "shell.h" 461556Srgrimes#define DEFINE_OPTIONS 471556Srgrimes#include "options.h" 481556Srgrimes#undef DEFINE_OPTIONS 491556Srgrimes#include "nodes.h" /* for other header files */ 501556Srgrimes#include "eval.h" 511556Srgrimes#include "jobs.h" 521556Srgrimes#include "input.h" 531556Srgrimes#include "output.h" 541556Srgrimes#include "trap.h" 551556Srgrimes#include "var.h" 561556Srgrimes#include "memalloc.h" 571556Srgrimes#include "error.h" 581556Srgrimes#include "mystring.h" 5917987Speter#ifndef NO_HISTORY 6017987Speter#include "myhistedit.h" 6117987Speter#endif 621556Srgrimes 631556Srgrimeschar *arg0; /* value of $0 */ 641556Srgrimesstruct shparam shellparam; /* current positional parameters */ 651556Srgrimeschar **argptr; /* argument list for builtin commands */ 6659436Scracauerchar *shoptarg; /* set by nextopt (like getopt) */ 671556Srgrimeschar *optptr; /* used by nextopt */ 681556Srgrimes 691556Srgrimeschar *minusc; /* argument to -c option */ 701556Srgrimes 711556Srgrimes 7290111SimpSTATIC void options(int); 7390111SimpSTATIC void minus_o(char *, int); 7490111SimpSTATIC void setoption(int, int); 7590111SimpSTATIC int getopts(char *, char *, char **, char ***, char **); 761556Srgrimes 771556Srgrimes 781556Srgrimes/* 791556Srgrimes * Process the shell command line arguments. 801556Srgrimes */ 811556Srgrimes 821556Srgrimesvoid 8390111Simpprocargs(int argc, char **argv) 8417987Speter{ 851556Srgrimes int i; 861556Srgrimes 871556Srgrimes argptr = argv; 881556Srgrimes if (argc > 0) 891556Srgrimes argptr++; 901556Srgrimes for (i = 0; i < NOPTS; i++) 911556Srgrimes optlist[i].val = 2; 9219240Ssteve privileged = (getuid() != geteuid() || getgid() != getegid()); 931556Srgrimes options(1); 941556Srgrimes if (*argptr == NULL && minusc == NULL) 951556Srgrimes sflag = 1; 961556Srgrimes if (iflag == 2 && sflag == 1 && isatty(0) && isatty(1)) 971556Srgrimes iflag = 1; 981556Srgrimes if (mflag == 2) 991556Srgrimes mflag = iflag; 1001556Srgrimes for (i = 0; i < NOPTS; i++) 1011556Srgrimes if (optlist[i].val == 2) 1021556Srgrimes optlist[i].val = 0; 1031556Srgrimes arg0 = argv[0]; 1041556Srgrimes if (sflag == 0 && minusc == NULL) { 1051556Srgrimes commandname = arg0 = *argptr++; 1061556Srgrimes setinputfile(commandname, 0); 1071556Srgrimes } 10820425Ssteve /* POSIX 1003.2: first arg after -c cmd is $0, remainder $1... */ 10925227Ssteve if (argptr && minusc && *argptr) 11011111Sjoerg arg0 = *argptr++; 11120742Ssteve 1121556Srgrimes shellparam.p = argptr; 11320742Ssteve shellparam.reset = 1; 1141556Srgrimes /* assert(shellparam.malloc == 0 && shellparam.nparam == 0); */ 1151556Srgrimes while (*argptr) { 1161556Srgrimes shellparam.nparam++; 1171556Srgrimes argptr++; 1181556Srgrimes } 1191556Srgrimes optschanged(); 1201556Srgrimes} 1211556Srgrimes 1221556Srgrimes 12317987Spetervoid 12490111Simpoptschanged(void) 12517987Speter{ 1261556Srgrimes setinteractive(iflag); 12717987Speter#ifndef NO_HISTORY 1281556Srgrimes histedit(); 12917987Speter#endif 1301556Srgrimes setjobctl(mflag); 1311556Srgrimes} 1321556Srgrimes 1331556Srgrimes/* 1341556Srgrimes * Process shell options. The global variable argptr contains a pointer 1351556Srgrimes * to the argument list; we advance it past the options. 1361556Srgrimes */ 1371556Srgrimes 1381556SrgrimesSTATIC void 13990111Simpoptions(int cmdline) 14017987Speter{ 141146255Sgad char *kp, *p; 1421556Srgrimes int val; 1431556Srgrimes int c; 1441556Srgrimes 1451556Srgrimes if (cmdline) 1461556Srgrimes minusc = NULL; 1471556Srgrimes while ((p = *argptr) != NULL) { 1481556Srgrimes argptr++; 1491556Srgrimes if ((c = *p++) == '-') { 1501556Srgrimes val = 1; 151141962Sgad /* A "-" or "--" terminates options */ 152141962Sgad if (p[0] == '\0') 153141962Sgad goto end_options1; 154141962Sgad if (p[0] == '-' && p[1] == '\0') 155141962Sgad goto end_options2; 156146255Sgad /** 157146255Sgad * For the benefit of `#!' lines in shell scripts, 158146255Sgad * treat a string of '-- *#.*' the same as '--'. 159146255Sgad * This is needed so that a script starting with: 160146255Sgad * #!/bin/sh -- # -*- perl -*- 161146255Sgad * will continue to work after a change is made to 162146255Sgad * kern/imgact_shell.c to NOT token-ize the options 163146255Sgad * specified on a '#!' line. A bit of a kludge, 164146255Sgad * but that trick is recommended in documentation 165146255Sgad * for some scripting languages, and we might as 166146255Sgad * well continue to support it. 167146255Sgad */ 168146255Sgad if (p[0] == '-') { 169146255Sgad kp = p + 1; 170146255Sgad while (*kp == ' ' || *kp == '\t') 171146255Sgad kp++; 172146255Sgad if (*kp == '#' || *kp == '\0') 173146255Sgad goto end_options2; 174146255Sgad } 1751556Srgrimes } else if (c == '+') { 1761556Srgrimes val = 0; 1771556Srgrimes } else { 1781556Srgrimes argptr--; 1791556Srgrimes break; 1801556Srgrimes } 1811556Srgrimes while ((c = *p++) != '\0') { 1821556Srgrimes if (c == 'c' && cmdline) { 1831556Srgrimes char *q; 1841556Srgrimes#ifdef NOHACK /* removing this code allows sh -ce 'foo' for compat */ 1851556Srgrimes if (*p == '\0') 1861556Srgrimes#endif 1871556Srgrimes q = *argptr++; 1881556Srgrimes if (q == NULL || minusc != NULL) 1891556Srgrimes error("Bad -c option"); 1901556Srgrimes minusc = q; 1911556Srgrimes#ifdef NOHACK 1921556Srgrimes break; 1931556Srgrimes#endif 1941556Srgrimes } else if (c == 'o') { 1951556Srgrimes minus_o(*argptr, val); 1961556Srgrimes if (*argptr) 1971556Srgrimes argptr++; 1981556Srgrimes } else { 19919240Ssteve if (c == 'p' && !val && privileged) { 20019240Ssteve (void) setuid(getuid()); 20119240Ssteve (void) setgid(getgid()); 20219240Ssteve } 2031556Srgrimes setoption(c, val); 2041556Srgrimes } 2051556Srgrimes } 2061556Srgrimes } 207141962Sgad return; 208141962Sgad 209141962Sgad /* When processing `set', a single "-" means turn off -x and -v */ 210141962Sgadend_options1: 211141962Sgad if (!cmdline) { 212141962Sgad xflag = vflag = 0; 213141962Sgad return; 214141962Sgad } 215141962Sgad 216141962Sgad /* 217141962Sgad * When processing `set', a "--" means the remaining arguments 218141962Sgad * replace the positional parameters in the active shell. If 219141962Sgad * there are no remaining options, then all the positional 220141962Sgad * parameters are cleared (equivalent to doing ``shift $#''). 221141962Sgad */ 222141962Sgadend_options2: 223141962Sgad if (!cmdline) { 224141962Sgad if (*argptr == NULL) 225141962Sgad setparam(argptr); 226141962Sgad return; 227141962Sgad } 228141962Sgad 229141962Sgad /* 230141962Sgad * At this point we are processing options given to 'sh' on a command 231141962Sgad * line. If an end-of-options marker ("-" or "--") is followed by an 232141962Sgad * arg of "#", then skip over all remaining arguments. Some scripting 233141962Sgad * languages (e.g.: perl) document that /bin/sh will implement this 234141962Sgad * behavior, and they recommend that users take advantage of it to 235141962Sgad * solve certain issues that can come up when writing a perl script. 236141962Sgad * Yes, this feature is in /bin/sh to help users write perl scripts. 237141962Sgad */ 238141962Sgad p = *argptr; 239141962Sgad if (p != NULL && p[0] == '#' && p[1] == '\0') { 240141962Sgad while (*argptr != NULL) 241141962Sgad argptr++; 242141962Sgad /* We need to keep the final argument */ 243141962Sgad argptr--; 244141962Sgad } 2451556Srgrimes} 2461556Srgrimes 2471556SrgrimesSTATIC void 24890111Simpminus_o(char *name, int val) 2491556Srgrimes{ 250151866Sstefanf int i; 2511556Srgrimes 2521556Srgrimes if (name == NULL) { 25397276Stjr if (val) { 25497276Stjr /* "Pretty" output. */ 25597276Stjr out1str("Current option settings\n"); 25697276Stjr for (i = 0; i < NOPTS; i++) 25797276Stjr out1fmt("%-16s%s\n", optlist[i].name, 25897276Stjr optlist[i].val ? "on" : "off"); 25997276Stjr } else { 26097276Stjr /* Output suitable for re-input to shell. */ 261151866Sstefanf for (i = 0; i < NOPTS; i++) { 262151866Sstefanf if (i % 6 == 0) 263151866Sstefanf out1str(i == 0 ? "set" : "\nset"); 264151866Sstefanf out1fmt(" %co %s", optlist[i].val ? '-' : '+', 265151866Sstefanf optlist[i].name); 266151866Sstefanf } 267151866Sstefanf out1c('\n'); 26897276Stjr } 2691556Srgrimes } else { 2701556Srgrimes for (i = 0; i < NOPTS; i++) 2711556Srgrimes if (equal(name, optlist[i].name)) { 27219240Ssteve if (!val && privileged && equal(name, "privileged")) { 27319240Ssteve (void) setuid(getuid()); 27419240Ssteve (void) setgid(getgid()); 27519240Ssteve } 2761556Srgrimes setoption(optlist[i].letter, val); 2771556Srgrimes return; 2781556Srgrimes } 2791556Srgrimes error("Illegal option -o %s", name); 2801556Srgrimes } 2811556Srgrimes} 2821556Srgrimes 2838855Srgrimes 2841556SrgrimesSTATIC void 28590111Simpsetoption(int flag, int val) 28690111Simp{ 2871556Srgrimes int i; 2881556Srgrimes 2891556Srgrimes for (i = 0; i < NOPTS; i++) 2901556Srgrimes if (optlist[i].letter == flag) { 2911556Srgrimes optlist[i].val = val; 2921556Srgrimes if (val) { 2931556Srgrimes /* #%$ hack for ksh semantics */ 2941556Srgrimes if (flag == 'V') 2951556Srgrimes Eflag = 0; 2961556Srgrimes else if (flag == 'E') 2971556Srgrimes Vflag = 0; 2981556Srgrimes } 2991556Srgrimes return; 3001556Srgrimes } 3011556Srgrimes error("Illegal option -%c", flag); 3021556Srgrimes} 3031556Srgrimes 3041556Srgrimes 3051556Srgrimes 3061556Srgrimes#ifdef mkinit 3071556SrgrimesINCLUDE "options.h" 3081556Srgrimes 3091556SrgrimesSHELLPROC { 3101556Srgrimes int i; 3111556Srgrimes 3121556Srgrimes for (i = 0; i < NOPTS; i++) 3131556Srgrimes optlist[i].val = 0; 3141556Srgrimes optschanged(); 3151556Srgrimes 3161556Srgrimes} 3171556Srgrimes#endif 3181556Srgrimes 3191556Srgrimes 3201556Srgrimes/* 3211556Srgrimes * Set the shell parameters. 3221556Srgrimes */ 3231556Srgrimes 3241556Srgrimesvoid 32590111Simpsetparam(char **argv) 32690111Simp{ 3271556Srgrimes char **newparam; 3281556Srgrimes char **ap; 3291556Srgrimes int nparam; 3301556Srgrimes 3311556Srgrimes for (nparam = 0 ; argv[nparam] ; nparam++); 3321556Srgrimes ap = newparam = ckmalloc((nparam + 1) * sizeof *ap); 3331556Srgrimes while (*argv) { 3341556Srgrimes *ap++ = savestr(*argv++); 3351556Srgrimes } 3361556Srgrimes *ap = NULL; 3371556Srgrimes freeparam(&shellparam); 3381556Srgrimes shellparam.malloc = 1; 3391556Srgrimes shellparam.nparam = nparam; 3401556Srgrimes shellparam.p = newparam; 3411556Srgrimes shellparam.optnext = NULL; 3421556Srgrimes} 3431556Srgrimes 3441556Srgrimes 3451556Srgrimes/* 3461556Srgrimes * Free the list of positional parameters. 3471556Srgrimes */ 3481556Srgrimes 3491556Srgrimesvoid 35090111Simpfreeparam(struct shparam *param) 35190111Simp{ 3521556Srgrimes char **ap; 3531556Srgrimes 3541556Srgrimes if (param->malloc) { 3551556Srgrimes for (ap = param->p ; *ap ; ap++) 3561556Srgrimes ckfree(*ap); 3571556Srgrimes ckfree(param->p); 3581556Srgrimes } 3591556Srgrimes} 3601556Srgrimes 3611556Srgrimes 3621556Srgrimes 3631556Srgrimes/* 3641556Srgrimes * The shift builtin command. 3651556Srgrimes */ 3661556Srgrimes 36717987Speterint 36890111Simpshiftcmd(int argc, char **argv) 36917987Speter{ 3701556Srgrimes int n; 3711556Srgrimes char **ap1, **ap2; 3721556Srgrimes 3731556Srgrimes n = 1; 3741556Srgrimes if (argc > 1) 3751556Srgrimes n = number(argv[1]); 3761556Srgrimes if (n > shellparam.nparam) 3771556Srgrimes error("can't shift that many"); 3781556Srgrimes INTOFF; 3791556Srgrimes shellparam.nparam -= n; 3801556Srgrimes for (ap1 = shellparam.p ; --n >= 0 ; ap1++) { 3811556Srgrimes if (shellparam.malloc) 3821556Srgrimes ckfree(*ap1); 3831556Srgrimes } 3841556Srgrimes ap2 = shellparam.p; 3851556Srgrimes while ((*ap2++ = *ap1++) != NULL); 3861556Srgrimes shellparam.optnext = NULL; 3871556Srgrimes INTON; 3881556Srgrimes return 0; 3891556Srgrimes} 3901556Srgrimes 3911556Srgrimes 3921556Srgrimes 3931556Srgrimes/* 3941556Srgrimes * The set command builtin. 3951556Srgrimes */ 3961556Srgrimes 39717987Speterint 39890111Simpsetcmd(int argc, char **argv) 39917987Speter{ 4001556Srgrimes if (argc == 1) 4011556Srgrimes return showvarscmd(argc, argv); 4021556Srgrimes INTOFF; 4031556Srgrimes options(0); 4041556Srgrimes optschanged(); 4051556Srgrimes if (*argptr != NULL) { 4061556Srgrimes setparam(argptr); 4071556Srgrimes } 4081556Srgrimes INTON; 4091556Srgrimes return 0; 4101556Srgrimes} 4111556Srgrimes 4121556Srgrimes 41320425Sstevevoid 41490111Simpgetoptsreset(const char *value) 41520425Ssteve{ 41620425Ssteve if (number(value) == 1) { 41720425Ssteve shellparam.optnext = NULL; 41820425Ssteve shellparam.reset = 1; 41920425Ssteve } 42020425Ssteve} 42120425Ssteve 4221556Srgrimes/* 4231556Srgrimes * The getopts builtin. Shellparam.optnext points to the next argument 4241556Srgrimes * to be processed. Shellparam.optptr points to the next character to 4251556Srgrimes * be processed in the current argument. If shellparam.optnext is NULL, 4261556Srgrimes * then it's the first time getopts has been called. 4271556Srgrimes */ 4281556Srgrimes 42917987Speterint 43090111Simpgetoptscmd(int argc, char **argv) 43117987Speter{ 43220425Ssteve char **optbase = NULL; 43320425Ssteve 43420425Ssteve if (argc < 3) 43595258Sdes error("usage: getopts optstring var [arg]"); 43620425Ssteve else if (argc == 3) 43720425Ssteve optbase = shellparam.p; 43820425Ssteve else 43920425Ssteve optbase = &argv[3]; 44020425Ssteve 44120425Ssteve if (shellparam.reset == 1) { 44220425Ssteve shellparam.optnext = optbase; 44320425Ssteve shellparam.optptr = NULL; 44420425Ssteve shellparam.reset = 0; 44520425Ssteve } 44620425Ssteve 44720425Ssteve return getopts(argv[1], argv[2], optbase, &shellparam.optnext, 44820425Ssteve &shellparam.optptr); 44920425Ssteve} 45020425Ssteve 45120425SsteveSTATIC int 45290111Simpgetopts(char *optstr, char *optvar, char **optfirst, char ***optnext, 45390111Simp char **optptr) 45420425Ssteve{ 45525227Ssteve char *p, *q; 45620425Ssteve char c = '?'; 45720425Ssteve int done = 0; 45820425Ssteve int ind = 0; 45920425Ssteve int err = 0; 4601556Srgrimes char s[10]; 4611556Srgrimes 46220425Ssteve if ((p = *optptr) == NULL || *p == '\0') { 46320425Ssteve /* Current word is done, advance */ 46420425Ssteve if (*optnext == NULL) 46520425Ssteve return 1; 46620425Ssteve p = **optnext; 4671556Srgrimes if (p == NULL || *p != '-' || *++p == '\0') { 4681556Srgrimesatend: 46920742Ssteve ind = *optnext - optfirst + 1; 47020425Ssteve *optnext = NULL; 47120742Ssteve p = NULL; 47220425Ssteve done = 1; 47320425Ssteve goto out; 4741556Srgrimes } 47520425Ssteve (*optnext)++; 4761556Srgrimes if (p[0] == '-' && p[1] == '\0') /* check for "--" */ 4771556Srgrimes goto atend; 4781556Srgrimes } 47920425Ssteve 4801556Srgrimes c = *p++; 48120425Ssteve for (q = optstr; *q != c; ) { 4821556Srgrimes if (*q == '\0') { 48320425Ssteve if (optstr[0] == ':') { 48420425Ssteve s[0] = c; 48520425Ssteve s[1] = '\0'; 48620425Ssteve err |= setvarsafe("OPTARG", s, 0); 48720425Ssteve } 48820425Ssteve else { 48920425Ssteve out1fmt("Illegal option -%c\n", c); 49020425Ssteve (void) unsetvar("OPTARG"); 49120425Ssteve } 4921556Srgrimes c = '?'; 49320425Ssteve goto bad; 4941556Srgrimes } 4951556Srgrimes if (*++q == ':') 4961556Srgrimes q++; 4971556Srgrimes } 49820425Ssteve 4991556Srgrimes if (*++q == ':') { 50020425Ssteve if (*p == '\0' && (p = **optnext) == NULL) { 50120425Ssteve if (optstr[0] == ':') { 50220425Ssteve s[0] = c; 50320425Ssteve s[1] = '\0'; 50420425Ssteve err |= setvarsafe("OPTARG", s, 0); 50520425Ssteve c = ':'; 50620425Ssteve } 50720425Ssteve else { 50820425Ssteve out1fmt("No arg for -%c option\n", c); 50920425Ssteve (void) unsetvar("OPTARG"); 51020425Ssteve c = '?'; 51120425Ssteve } 51220425Ssteve goto bad; 5131556Srgrimes } 51420425Ssteve 51520425Ssteve if (p == **optnext) 51620425Ssteve (*optnext)++; 51720425Ssteve setvarsafe("OPTARG", p, 0); 5181556Srgrimes p = NULL; 5191556Srgrimes } 52020425Ssteve else 52120425Ssteve setvarsafe("OPTARG", "", 0); 52220425Ssteve ind = *optnext - optfirst + 1; 52320425Ssteve goto out; 52420425Ssteve 52520425Sstevebad: 52620425Ssteve ind = 1; 52720425Ssteve *optnext = NULL; 52820425Ssteve p = NULL; 5291556Srgrimesout: 53020425Ssteve *optptr = p; 53120425Ssteve fmtstr(s, sizeof(s), "%d", ind); 53220425Ssteve err |= setvarsafe("OPTIND", s, VNOFUNC); 5331556Srgrimes s[0] = c; 5341556Srgrimes s[1] = '\0'; 53520425Ssteve err |= setvarsafe(optvar, s, 0); 53620425Ssteve if (err) { 53720425Ssteve *optnext = NULL; 53820425Ssteve *optptr = NULL; 53920425Ssteve flushall(); 54020425Ssteve exraise(EXERROR); 54120425Ssteve } 54220425Ssteve return done; 5431556Srgrimes} 5441556Srgrimes 5451556Srgrimes/* 5461556Srgrimes * XXX - should get rid of. have all builtins use getopt(3). the 5471556Srgrimes * library getopt must have the BSD extension static variable "optreset" 5481556Srgrimes * otherwise it can't be used within the shell safely. 5491556Srgrimes * 5501556Srgrimes * Standard option processing (a la getopt) for builtin routines. The 5511556Srgrimes * only argument that is passed to nextopt is the option string; the 5521556Srgrimes * other arguments are unnecessary. It return the character, or '\0' on 5531556Srgrimes * end of input. 5541556Srgrimes */ 5551556Srgrimes 5561556Srgrimesint 55790111Simpnextopt(char *optstring) 55890111Simp{ 55925227Ssteve char *p, *q; 5601556Srgrimes char c; 5611556Srgrimes 5621556Srgrimes if ((p = optptr) == NULL || *p == '\0') { 5631556Srgrimes p = *argptr; 5641556Srgrimes if (p == NULL || *p != '-' || *++p == '\0') 5651556Srgrimes return '\0'; 5661556Srgrimes argptr++; 5671556Srgrimes if (p[0] == '-' && p[1] == '\0') /* check for "--" */ 5681556Srgrimes return '\0'; 5691556Srgrimes } 5701556Srgrimes c = *p++; 5711556Srgrimes for (q = optstring ; *q != c ; ) { 5721556Srgrimes if (*q == '\0') 5731556Srgrimes error("Illegal option -%c", c); 5741556Srgrimes if (*++q == ':') 5751556Srgrimes q++; 5761556Srgrimes } 5771556Srgrimes if (*++q == ':') { 5781556Srgrimes if (*p == '\0' && (p = *argptr++) == NULL) 5791556Srgrimes error("No arg for -%c option", c); 58059436Scracauer shoptarg = p; 5811556Srgrimes p = NULL; 5821556Srgrimes } 5831556Srgrimes optptr = p; 5841556Srgrimes return c; 5851556Srgrimes} 586