BSD 4_3_Reno release

[unix-history] / usr / src / lib / libc / gen / getopt.c

/*
* Copyright (c) 1987 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that: (1) source distributions retain this entire copyright
* notice and comment, and (2) distributions including binaries display
* the following acknowledgement:  ``This product includes software
* developed by the University of California, Berkeley and its contributors''
* in the documentation or other materials provided with the distribution
* and in all advertising materials mentioning features or use of this
* software. Neither the name of the University nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)getopt.c    4.12 (Berkeley) 6/1/90";
#endif /* LIBC_SCCS and not lint */

#include <stdio.h>

/*
* get option letter from argument vector
*/
int     opterr = 1,             /* if error message should be printed */
       optind = 1,             /* index into parent argv vector */
       optopt;                 /* character checked for validity */
char    *optarg;                /* argument associated with option */

#define BADCH   (int)'?'
#define EMSG    ""

getopt(nargc, nargv, ostr)
       int nargc;
       char **nargv, *ostr;
{
       static char *place = EMSG;              /* option letter processing */
       register char *oli;                     /* option letter list index */
       char *p, *index(), *rindex();

       if (!*place) {                          /* update scanning pointer */
               if (optind >= nargc || *(place = nargv[optind]) != '-') {
                       place = EMSG;
                       return(EOF);
               }
               if (place[1] && *++place == '-') {      /* found "--" */
                       ++optind;
                       place = EMSG;
                       return(EOF);
               }
       }                                       /* option letter okay? */
       if ((optopt = (int)*place++) == (int)':' ||
           !(oli = index(ostr, optopt))) {
               /*
                * if the user didn't specify '-' as an option,
                * assume it means EOF.
                */
               if (optopt == (int)'-')
                       return(EOF);
               if (!*place)
                       ++optind;
               if (opterr) {
                       if (!(p = rindex(*nargv, '/')))
                               p = *nargv;
                       else
                               ++p;
                       (void)fprintf(stderr, "%s: illegal option -- %c\n",
                           p, optopt);
               }
               return(BADCH);
       }
       if (*++oli != ':') {                    /* don't need argument */
               optarg = NULL;
               if (!*place)
                       ++optind;
       }
       else {                                  /* need an argument */
               if (*place)                     /* no white space */
                       optarg = place;
               else if (nargc <= ++optind) {   /* no arg */
                       place = EMSG;
                       if (!(p = rindex(*nargv, '/')))
                               p = *nargv;
                       else
                               ++p;
                       if (opterr)
                               (void)fprintf(stderr,
                                   "%s: option requires an argument -- %c\n",
                                   p, optopt);
                       return(BADCH);
               }
               else                            /* white space */
                       optarg = nargv[optind];
               place = EMSG;
               ++optind;
       }
       return(optopt);                         /* dump back option letter */
}