element-lists/names-2.0.1/src/getopt.c

   1 #include <stdio.h>
   2 #include <string.h> /* strchr */
   3 #include "getopt.h"
   4
   5 #define ERROR '?'
   6 #define FINISHED -1
   7
   8 #define NIL  0
   9 #define SWI  1
  10 #define OPT  2
  11 #define ARG  3
  12 #define DONE 4
  13
  14 int optind = 1;
  15 int opterr = 0;
  16 char *optarg = "";
  17
  18 int getopt(int argc, char **argv, char *str)
  19 {
  20         static int a=0;         /* index into argv[optind] */
  21         char *s;                /* index into str */
  22         static int opt=0;       /* are we currently looking at an option? */
  23         static int state=NIL;   /* current state */
  24
  25         opterr=0;
  26
  27         /* are we done? */
  28         if (optind >= argc) return FINISHED;
  29
  30         /* end of current arg? */
  31         if (argv[optind][a]==0)
  32         {
  33                 optind++; /* move on to next arg */
  34                 if (optind >= argc) return FINISHED; /* nothing more to do */
  35                 a=0;
  36                 state=NIL;
  37         }
  38
  39         optarg = argv[optind]; /* give it a default value */
  40
  41         /* look for next option */
  42         /* starting a new argument? */
  43         if (a==0)
  44         {
  45                 /* is it a switch? */
  46                 if (argv[optind][a]=='-' || argv[optind][a]=='/')
  47                 {
  48                         a++;            /* next char */
  49
  50                         /* if optarg is a single "-", finished */
  51                         if (argv[optind][a]==0)
  52                         {
  53                                 optind++;
  54                                 return FINISHED;
  55                         }
  56                         state = OPT;    /* now processing an opt */
  57                 }
  58                 /* not switched, must be an arg */
  59                 else return FINISHED;
  60         }
  61         else /* not a new argument */
  62         {
  63                 if (state != OPT) { printf("state!=OPT\n"); return '?'; }
  64         }
  65
  66         /* find the opt */
  67         s = strchr(str, argv[optind][a]);
  68         if (s == 0)
  69         {
  70                 fprintf(stderr,"unknown option '%c'\n", argv[optind][a]);
  71                 opterr=1;
  72                 return ERROR;
  73         }
  74         a++;
  75
  76         if (s[1]==':')
  77         {
  78                 if (argv[optind][a]==':')       /* allow  -o:str */
  79                         a++;
  80
  81                 if (argv[optind][a]==0)         /* handle -o str */
  82                 {
  83                         optind++;
  84                         if (optind >= argc)     /* oops, no optarg */
  85                         {
  86                                 fprintf(stderr,"option '%c' requires an argument\n", *s);
  87                                 opterr=1;
  88                                 return ERROR;
  89                         }
  90                         a=0;
  91                 }
  92
  93                 optarg = argv[optind]+a;        /* no longer in arg */
  94                 optind++;                       /* advance to next arg */
  95                 a=0;
  96                 state = NIL;                    /* reset state */
  97                 return *s;
  98         }
  99         else return *s; /* got valid option */
 100 }
 101