lib/libstand/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  * @(#)getopt.c 8.3 (Berkeley) 4/27/95
  30  * $DragonFly: src/lib/libstand/getopt.c,v 1.3 2005/12/11 02:27:26 swildner Exp $
  31  */
  32
  33 #include "stand.h"
  34 #include <string.h>
  35
  36 int     opterr = 1,             /* if error message should be printed */
  37         optind = 1,             /* index into parent argv vector */
  38         optopt,                 /* character checked for validity */
  39         optreset;               /* reset getopt */
  40 char    *optarg;                /* argument associated with option */
  41
  42 #define BADCH   (int)'?'
  43 #define BADARG  (int)':'
  44 #define EMSG    ""
  45
  46 /*
  47  * getopt --
  48  *      Parse argc/argv argument vector.
  49  */
  50 int
  51 getopt(int nargc, char * const *nargv, const char *ostr)
  52 {
  53         static char *place = EMSG;              /* option letter processing */
  54         char *oli;                              /* option letter list index */
  55
  56         if (optreset || !*place) {              /* update scanning pointer */
  57                 optreset = 0;
  58                 if (optind >= nargc || *(place = nargv[optind]) != '-') {
  59                         place = EMSG;
  60                         return (-1);
  61                 }
  62                 if (place[1] && *++place == '-') {      /* found "--" */
  63                         ++optind;
  64                         place = EMSG;
  65                         return (-1);
  66                 }
  67         }                                       /* option letter okay? */
  68         if ((optopt = (int)*place++) == (int)':' ||
  69             !(oli = strchr(ostr, optopt))) {
  70                 /*
  71                  * if the user didn't specify '-' as an option,
  72                  * assume it means -1.
  73                  */
  74                 if (optopt == (int)'-')
  75                         return (-1);
  76                 if (!*place)
  77                         ++optind;
  78                 if (opterr && *ostr != ':')
  79                         (void)printf("illegal option -- %c\n", optopt);
  80                 return (BADCH);
  81         }
  82         if (*++oli != ':') {                    /* don't need argument */
  83                 optarg = NULL;
  84                 if (!*place)
  85                         ++optind;
  86         }
  87         else {                                  /* need an argument */
  88                 if (*place)                     /* no white space */
  89                         optarg = place;
  90                 else if (nargc <= ++optind) {   /* no arg */
  91                         place = EMSG;
  92                         if (*ostr == ':')
  93                                 return (BADARG);
  94                         if (opterr)
  95                                 (void)printf("option requires an argument -- %c\n", optopt);
  96                         return (BADCH);
  97                 }
  98                 else                            /* white space */
  99                         optarg = nargv[optind];
 100                 place = EMSG;
 101                 ++optind;
 102         }
 103         return (optopt);                        /* dump back option letter */
 104 }