lib/libc/stdlib/getopt.c

   1 /*      $NetBSD: getopt.c,v 1.26 2003/08/07 16:43:40 agc Exp $  */
   2
   3 /*
   4  * Copyright (c) 1987, 1993, 1994
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  *
  31  * @(#)getopt.c 8.3 (Berkeley) 4/27/95
  32  * $FreeBSD: src/lib/libc/stdlib/getopt.c,v 1.8 2007/01/09 00:28:10 imp Exp $
  33  */
  34
  35 #include "namespace.h"
  36 #include <stdio.h>
  37 #include <stdlib.h>
  38 #include <string.h>
  39 #include <unistd.h>
  40 #include "un-namespace.h"
  41
  42 #include "libc_private.h"
  43
  44 int     opterr = 1,             /* if error message should be printed */
  45         optind = 1,             /* index into parent argv vector */
  46         optopt,                 /* character checked for validity */
  47         optreset;               /* reset getopt */
  48 char    *optarg;                /* argument associated with option */
  49
  50 #define BADCH   (int)'?'
  51 #define BADARG  (int)':'
  52
  53 static char EMSG[] = { '\0' };
  54
  55 /*
  56  * getopt --
  57  *      Parse argc/argv argument vector.
  58  */
  59 int
  60 getopt(int nargc, char * const nargv[], const char *ostr)
  61 {
  62         static char *place = EMSG;              /* option letter processing */
  63         char *oli;                              /* option letter list index */
  64
  65         /*
  66          * Some programs like cvs expect optind = 0 to trigger
  67          * a reset of getopt.
  68          */
  69         if (optind == 0)
  70                 optind = 1;
  71
  72         if (optreset || *place == 0) {          /* update scanning pointer */
  73                 optreset = 0;
  74                 place = nargv[optind];
  75                 if (optind >= nargc || *place++ != '-') {
  76                         /* Argument is absent or is not an option */
  77                         place = EMSG;
  78                         return (-1);
  79                 }
  80                 optopt = *place++;
  81                 if (optopt == '-' && *place == 0) {
  82                         /* "--" => end of options */
  83                         ++optind;
  84                         place = EMSG;
  85                         return (-1);
  86                 }
  87                 if (optopt == 0) {
  88                         /* Solitary '-', treat as a '-' option
  89                            if the program (eg su) is looking for it. */
  90                         place = EMSG;
  91                         if (strchr(ostr, '-') == NULL)
  92                                 return (-1);
  93                         optopt = '-';
  94                 }
  95         } else
  96                 optopt = *place++;
  97
  98         /* See if option letter is one the caller wanted... */
  99         if (optopt == ':' || (oli = strchr(ostr, optopt)) == NULL) {
 100                 if (*place == 0)
 101                         ++optind;
 102                 if (opterr && *ostr != ':')
 103                         fprintf(stderr,
 104                             "%s: illegal option -- %c\n", _getprogname(),
 105                             optopt);
 106                 return (BADCH);
 107         }
 108
 109         /* Does this option need an argument? */
 110         if (oli[1] != ':') {
 111                 /* don't need argument */
 112                 optarg = NULL;
 113                 if (*place == 0)
 114                         ++optind;
 115         } else {
 116                 /* Option-argument is either the rest of this argument or the
 117                    entire next argument. */
 118                 if (*place)
 119                         optarg = place;
 120                 else if (oli[2] == ':')
 121                         /*
 122                          * GNU Extension, for optional arguments if the rest of
 123                          * the argument is empty, we return NULL
 124                          */
 125                         optarg = NULL;
 126                 else if (nargc > ++optind)
 127                         optarg = nargv[optind];
 128                 else {
 129                         /* option-argument absent */
 130                         place = EMSG;
 131                         if (*ostr == ':')
 132                                 return (BADARG);
 133                         if (opterr)
 134                                 fprintf(stderr,
 135                                     "%s: option requires an argument -- %c\n",
 136                                     _getprogname(), optopt);
 137                         return (BADCH);
 138                 }
 139                 place = EMSG;
 140                 ++optind;
 141         }
 142         return (optopt);                        /* return option letter */
 143 }