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