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. 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  * @(#)getopt.c 8.3 (Berkeley) 4/27/95
  34  * $DragonFly: src/lib/libstand/getopt.c,v 1.3 2005/12/11 02:27:26 swildner Exp $
  35  */
  36
  37 #include "stand.h"
  38 #include <string.h>
  39
  40 int     opterr = 1,             /* if error message should be printed */
  41         optind = 1,             /* index into parent argv vector */
  42         optopt,                 /* character checked for validity */
  43         optreset;               /* reset getopt */
  44 char    *optarg;                /* argument associated with option */
  45
  46 #define BADCH   (int)'?'
  47 #define BADARG  (int)':'
  48 #define EMSG    ""
  49
  50 /*
  51  * getopt --
  52  *      Parse argc/argv argument vector.
  53  */
  54 int
  55 getopt(int nargc, char * const *nargv, const char *ostr)
  56 {
  57         static char *place = EMSG;              /* option letter processing */
  58         char *oli;                              /* option letter list index */
  59
  60         if (optreset || !*place) {              /* update scanning pointer */
  61                 optreset = 0;
  62                 if (optind >= nargc || *(place = nargv[optind]) != '-') {
  63                         place = EMSG;
  64                         return (-1);
  65                 }
  66                 if (place[1] && *++place == '-') {      /* found "--" */
  67                         ++optind;
  68                         place = EMSG;
  69                         return (-1);
  70                 }
  71         }                                       /* option letter okay? */
  72         if ((optopt = (int)*place++) == (int)':' ||
  73             !(oli = strchr(ostr, optopt))) {
  74                 /*
  75                  * if the user didn't specify '-' as an option,
  76                  * assume it means -1.
  77                  */
  78                 if (optopt == (int)'-')
  79                         return (-1);
  80                 if (!*place)
  81                         ++optind;
  82                 if (opterr && *ostr != ':')
  83                         (void)printf("illegal option -- %c\n", optopt);
  84                 return (BADCH);
  85         }
  86         if (*++oli != ':') {                    /* don't need argument */
  87                 optarg = NULL;
  88                 if (!*place)
  89                         ++optind;
  90         }
  91         else {                                  /* need an argument */
  92                 if (*place)                     /* no white space */
  93                         optarg = place;
  94                 else if (nargc <= ++optind) {   /* no arg */
  95                         place = EMSG;
  96                         if (*ostr == ':')
  97                                 return (BADARG);
  98                         if (opterr)
  99                                 (void)printf("option requires an argument -- %c\n", optopt);
 100                         return (BADCH);
 101                 }
 102                 else                            /* white space */
 103                         optarg = nargv[optind];
 104                 place = EMSG;
 105                 ++optind;
 106         }
 107         return (optopt);                        /* dump back option letter */
 108 }