getopt.c

00001 /*
00002  * Copyright (c) 1987, 1993, 1994
00003  *      The Regents of the University of California.  All rights reserved.
00004  *
00005  * Redistribution and use in source and binary forms, with or without
00006  * modification, are permitted provided that the following conditions
00007  * are met:
00008  * 1. Redistributions of source code must retain the above copyright
00009  *    notice, this list of conditions and the following disclaimer.
00010  * 2. Redistributions in binary form must reproduce the above copyright
00011  *    notice, this list of conditions and the following disclaimer in the
00012  *    documentation and/or other materials provided with the distribution.
00013  * 3. Neither the name of the University nor the names of its contributors
00014  *    may be used to endorse or promote products derived from this software
00015  *    without specific prior written permission.
00016  *
00017  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
00018  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
00019  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
00020  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
00021  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
00022  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
00023  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
00024  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
00025  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
00026  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
00027  * SUCH DAMAGE.
00028  */
00029 
00030 #if defined(LIBC_SCCS) && !defined(lint)
00031 /*
00032  * static char sccsid[] = "from: @(#)getopt.c   8.2 (Berkeley) 4/2/94"; 
00033  */
00034 static char    *rcsid =
00035     "$Id$";
00036 #endif                          /* LIBC_SCCS and not lint */
00037 
00038 #include <stdio.h>
00039 #include <stdlib.h>
00040 #include <string.h>
00041 
00042 #ifdef _BSD
00043 extern char    *__progname;
00044 #else
00045 #define __progname "getopt"
00046 #endif
00047 
00048 int             opterr = 1,     /* if error message should be printed */
00049                 optind = 1,     /* index into parent argv vector */
00050                 optopt,         /* character checked for validity */
00051                 optreset;       /* reset getopt */
00052 char           *optarg;         /* argument associated with option */
00053 char            EMSG[] = "";
00054 
00055 #define BADCH   (int)'?'
00056 #define BADARG  (int)':'
00057 
00058 /*
00059  * getopt --
00060  *      Parse argc/argv argument vector.
00061  */
00062 int
00063 getopt(int nargc, char *const *nargv, const char *ostr)
00064 {
00065     static char    *place = EMSG;       /* option letter processing */
00066     char           *oli;        /* option letter list index */
00067 
00068     if (optreset || !*place) {  /* update scanning pointer */
00069         optreset = 0;
00070         if (optind >= nargc || *(place = nargv[optind]) != '-') {
00071             place = EMSG;
00072             return (-1);
00073         }
00074         if (place[1] && *++place == '-') {      /* found "--" */
00075             ++optind;
00076             place = EMSG;
00077             return (-1);
00078         }
00079     }                           /* option letter okay? */
00080     if ((optopt = (int) *place++) == (int) ':' ||
00081         !(oli = strchr(ostr, optopt))) {
00082         /*
00083          * if the user didn't specify '-' as an option,
00084          * assume it means -1.
00085          */
00086         if (optopt == (int) '-')
00087             return (-1);
00088         if (!*place)
00089             ++optind;
00090         if (opterr && *ostr != ':')
00091             (void) fprintf(stderr,
00092                            "%s: illegal option -- %c\n", __progname,
00093                            optopt);
00094         return (BADCH);
00095     }
00096     if (*++oli != ':') {        /* don't need argument */
00097         optarg = NULL;
00098         if (!*place)
00099             ++optind;
00100     } else {                    /* need an argument */
00101         if (*place)             /* no white space */
00102             optarg = place;
00103         else if (nargc <= ++optind) {   /* no arg */
00104             place = EMSG;
00105             if (*ostr == ':')
00106                 return (BADARG);
00107             if (opterr)
00108                 (void) fprintf(stderr,
00109                                "%s: option requires an argument -- %c\n",
00110                                __progname, optopt);
00111             return (BADCH);
00112         } else                  /* white space */
00113             optarg = nargv[optind];
00114         place = EMSG;
00115         ++optind;
00116     }
00117     return (optopt);            /* dump back option letter */
00118 }