1 /* subgetopt.c, subgetopt.h: (yet another) improved getopt clone, inner layer

     2 D. J. Bernstein, djb@pobox.com.

     3 No dependencies.

     4 No system requirements.

     5 19970228: Cleanups.

     6 931129: Adapted from getopt.c.

     7 No known patent problems.

     8 

     9 Documentation in subgetopt.3.

    10 */

    11 

    12 #define SUBGETOPTNOSHORT

    13 #include "subgetopt.h"

    14 

    15 #define sgopt subgetopt

    16 #define optind subgetoptind

    17 #define optpos subgetoptpos

    18 #define optarg subgetoptarg

    19 #define optproblem subgetoptproblem

    20 #define optdone subgetoptdone

    21 

    22 int optind = 1;

    23 int optpos = 0;

    24 char *optarg = 0;

    25 int optproblem = 0;

    26 int optdone = SUBGETOPTDONE;

    27 

    28 int sgopt(argc,argv,opts)

    29 int argc;

    30 char **argv;

    31 char *opts;

    32 {

    33   int c;

    34   char *s;

    35 

    36   optarg = 0;

    37   if (!argv || (optind >= argc) || !argv[optind]) return optdone;

    38   if (optpos && !argv[optind][optpos]) {

    39     ++optind;

    40     optpos = 0;

    41     if ((optind >= argc) || !argv[optind]) return optdone;

    42   }

    43   if (!optpos) {

    44     if (argv[optind][0] != '-') return optdone;

    45     ++optpos;

    46     c = argv[optind][1];

    47     if ((c == '-') || (c == 0)) {

    48       if (c) ++optind;

    49       optpos = 0;

    50       return optdone;

    51     }

    52     /* otherwise c is reassigned below */

    53   }

    54   c = argv[optind][optpos];

    55   ++optpos;

    56   s = opts;

    57   while (*s) {

    58     if (c == *s) {

    59       if (s[1] == ':') {

    60         optarg = argv[optind] + optpos;

    61         ++optind;

    62         optpos = 0;

    63         if (!*optarg) {

    64           optarg = argv[optind];

    65           if ((optind >= argc) || !optarg) { /* argument past end */

    66             optproblem = c;

    67             return '?';

    68           }

    69 	  ++optind;

    70         }

    71       }

    72       return c;

    73     }

    74     ++s;

    75     if (*s == ':') ++s;

    76   }

    77   optproblem = c;

    78   return '?';

    79 }