avr/getopt-min.c

   1 #include "common.h"
   2
   3
   4 /*
   5  *      Minimum getopt, original version was:
   6  */
   7
   8 /*
   9         getopt -- public domain version of standard System V routine
  10
  11         Strictly enforces the System V Command Syntax Standard;
  12         provided by D A Gwyn of BRL for generic ANSI C implementations
  13 */
  14 /* $Id: getopt.c,v 1.2 1992/12/07 11:12:52 nickc Exp $ */
  15
  16 #include        <string.h>
  17
  18 int     optind = 1;                     /* next argv[] index */
  19 char *optarg;           /* option parameter if any */
  20
  21
  22 int
  23 getopt(                                 /* returns letter, '?', EOF */
  24         int             argc,           /* argument count from main */
  25         char    *const argv[],  /* argument vector from main */
  26         const FLASH char *optstring )           /* allowed args, e.g. "ab:c" */
  27 {
  28         static int      sp = 1;         /* position within argument */
  29         int             osp;            /* saved `sp' for param test */
  30         int             c;              /* option letter */
  31         const FLASH char *cp;           /* -> option in `optstring' */
  32
  33         optarg = NULL;
  34
  35         if ( sp == 1 )                  /* fresh argument */
  36         {
  37                 if ( optind >= argc             /* no more arguments */
  38                   || argv[optind][0] != '-'     /* no more options */
  39                   || argv[optind][1] == '\0'    /* not option; stdin */
  40                    )
  41                         return -1;
  42         }
  43
  44         c = argv[optind][sp];           /* option letter */
  45         osp = sp++;                     /* get ready for next letter */
  46
  47         if ( argv[optind][sp] == '\0' ) /* end of argument */
  48         {
  49                 ++optind;               /* get ready for next try */
  50                 sp = 1;                 /* beginning of next argument */
  51         }
  52
  53         if ( c == ':'                   /* optstring syntax conflict */
  54           || (cp = strchr_P( optstring, c )) == NULL    /* not found */
  55            )
  56                 return '?';
  57
  58         if ( cp[1] == ':' )             /* option takes parameter */
  59         {
  60                 if ( osp != 1 )
  61                         return '?';
  62
  63                 if ( sp != 1 )          /* reset by end of argument */
  64                         return '?';
  65
  66                 if ( optind >= argc )
  67                         return '?';
  68
  69                 optarg = argv[optind];  /* make parameter available */
  70                 ++optind;               /* skip over parameter */
  71         }
  72
  73         return c;
  74 }
  75