lib/getopt.c

   1 /*
   2  * getopt.c - a simple getopt(3) implementation. See getopt.h for explanation.
   3  *
   4  * Copyright (c) 2007 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  */
  19
  20 #include <common.h>
  21 #include <module.h>
  22 #include <getopt.h>
  23
  24 int opterr = 1;
  25 int optind = 1;
  26 int optopt;
  27 char *optarg;
  28
  29 EXPORT_SYMBOL(optind);
  30 EXPORT_SYMBOL(opterr);
  31 EXPORT_SYMBOL(optopt);
  32 EXPORT_SYMBOL(optarg);
  33
  34 static int optindex = 1; /* option index in the current argv[] element */
  35 static int nonopts = 0;  /* number of nonopts found */
  36
  37 void getopt_reset(void)
  38 {
  39         optind = opterr = optindex = 1;
  40         nonopts = 0;
  41 }
  42 EXPORT_SYMBOL(getopt_reset);
  43
  44 int getopt(int argc, char *argv[], char *optstring)
  45 {
  46         char curopt;   /* current option character */
  47         char *curoptp; /* pointer to the current option in optstring */
  48
  49         while(1) {
  50 //              printf("optindex: %d nonopts: %d optind: %d\n", optindex, nonopts, optind);
  51
  52                 /* first put nonopts to the end */
  53                 while (optind + nonopts < argc && *argv[optind] != '-') {
  54                         int i;
  55                         char *tmp;
  56
  57                         nonopts++;
  58                         tmp = argv[optind];
  59                         for (i = optind; i + 1 < argc; i++)
  60                                 argv[i] = argv[i + 1];
  61                         argv[argc - 1] = tmp;
  62                 }
  63
  64                 if (optind + nonopts >= argc)
  65                         return -1;
  66
  67                 /* We have found an option */
  68                 curopt = argv[optind][optindex];
  69                 if (curopt)
  70                         break;
  71                 /* no more options in current argv[] element. Start
  72                  * over with looking for nonopts
  73                  */
  74                 optind++;
  75                 optindex = 1;
  76         }
  77
  78         /* look up current option in optstring */
  79         curoptp = strchr(optstring, curopt);
  80
  81         if (!curoptp) {
  82                 if (opterr)
  83                         printf("%s: invalid option -- %c\n", argv[0], curopt);
  84                 optopt = curopt;
  85                 optindex++;
  86                 return '?';
  87         }
  88
  89         if (*(curoptp + 1) != ':') {
  90                 /* option with no argument. Just return it */
  91                 optarg = NULL;
  92                 optindex++;
  93                 return curopt;
  94         }
  95
  96         if (*(curoptp + 1) && *(curoptp + 2) == ':') {
  97                 /* optional argument */
  98                 if (argv[optind][optindex + 1]) {
  99                         /* optional argument with directly following optarg */
 100                         optarg = argv[optind] + optindex + 1;
 101                         optindex = 1;
 102                         optind++;
 103                         return curopt;
 104                 }
 105                 if (optind + nonopts  + 1 == argc) {
 106                         /* We are at the last argv[] element */
 107                         optarg = NULL;
 108                         optind++;
 109                         return curopt;
 110                 }
 111                 if (*argv[optind + 1] != '-') {
 112                         /* optional argument with optarg in next argv[] element
 113                          */
 114                         optind++;
 115                         optarg = argv[optind];
 116                         optind++;
 117                         optindex = 1;
 118                         return curopt;
 119                 }
 120
 121                 /* no optional argument found */
 122                 optarg = NULL;
 123                 optindex = 1;
 124                 optind++;
 125                 return curopt;
 126         }
 127
 128         if (argv[optind][optindex + 1]) {
 129                 /* required argument with directly following optarg */
 130                 optarg = argv[optind] + optindex + 1;
 131                 optind++;
 132                 optindex = 1;
 133                 return curopt;
 134         }
 135
 136         optind++;
 137         optindex = 1;
 138
 139         if (optind + nonopts >= argc || argv[optind][0] == '-') {
 140                 if (opterr)
 141                         printf("option requires an argument -- %c\n",
 142                                 curopt);
 143                 optopt = curopt;
 144                 return ':';
 145         }
 146
 147         optarg = argv[optind];
 148         optind++;
 149         return curopt;
 150 }
 151 EXPORT_SYMBOL(getopt);