lib/getopt.c

   1 /*
   2  * Copyright (c) 1987, 1993, 1994
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 #if defined(LIBC_SCCS) && !defined(lint)
  31 static char sccsid[] = "@(#)getopt.c    8.3 (Berkeley) 4/27/95";
  32 #endif /* LIBC_SCCS and not lint */
  33
  34 #include <stdio.h>
  35 #include <stdlib.h>
  36 #include <string.h>
  37
  38 int opterr = 1,                 /* if error message should be printed */
  39     optind = 1,                 /* index into parent argv vector */
  40     optopt,                     /* character checked for validity */
  41     optreset;                   /* reset getopt */
  42 char *optarg;                   /* argument associated with option */
  43
  44 #define BADCH   (int)'?'
  45 #define BADARG  (int)':'
  46 #define EMSG    ""
  47
  48 /*
  49  * getopt --
  50  *      Parse argc/argv argument vector.
  51  */
  52 int
  53 getopt(nargc, nargv, ostr)
  54      int nargc;
  55      char *const *nargv;
  56      const char *ostr;
  57 {
  58     static char *place = EMSG;  /* option letter processing */
  59     char *oli;                  /* option letter list index */
  60
  61     if (optreset || !*place) {  /* update scanning pointer */
  62         optreset = 0;
  63         if (optind >= nargc || *(place = nargv[optind]) != '-') {
  64             place = EMSG;
  65             return (-1);
  66         }
  67         if (place[1] && *++place == '-') {      /* found "--" */
  68             ++optind;
  69             place = EMSG;
  70             return (-1);
  71         }
  72     }                           /* option letter okay? */
  73     if ((optopt = (int) *place++) == (int) ':' ||
  74         !(oli = strchr(ostr, optopt))) {
  75         /*
  76          * if the user didn't specify '-' as an option,
  77          * assume it means -1.
  78          */
  79         if (optopt == (int) '-')
  80             return (-1);
  81         if (!*place)
  82             ++optind;
  83         if (opterr && *ostr != ':')
  84             (void) fprintf(stderr,
  85                 "%s: illegal option -- %c\n", __FILE__, optopt);
  86         return (BADCH);
  87     }
  88     if (*++oli != ':') {        /* don't need argument */
  89         optarg = NULL;
  90         if (!*place)
  91             ++optind;
  92     } else {                    /* need an argument */
  93         if (*place)             /* no white space */
  94             optarg = place;
  95         else if (nargc <= ++optind) {   /* no arg */
  96             place = EMSG;
  97             if (*ostr == ':')
  98                 return (BADARG);
  99             if (opterr)
 100                 (void) fprintf(stderr,
 101                     "%s: option requires an argument -- %c\n",
 102                     __FILE__, optopt);
 103             return (BADCH);
 104         } else                  /* white space */
 105             optarg = nargv[optind];
 106         place = EMSG;
 107         ++optind;
 108     }
 109     return (optopt);            /* dump back option letter */
 110 }