avr/getopt-min.c

   1 #include "common.h"
   2 #include <avr/pgmspace.h>
   3
   4
   5 /*
   6  *      Minimum getopt, original version was:
   7  */
   8
   9 /*
  10         getopt -- public domain version of standard System V routine
  11
  12         Strictly enforces the System V Command Syntax Standard;
  13         provided by D A Gwyn of BRL for generic ANSI C implementations
  14 */
  15 /* $Id: getopt.c,v 1.2 1992/12/07 11:12:52 nickc Exp $ */
  16
  17 #include        <string.h>
  18
  19 int     optind = 1;                     /* next argv[] index */
  20 char *optarg;           /* option parameter if any */
  21
  22
  23 int
  24 getopt(                                 /* returns letter, '?', EOF */
  25         int             argc,           /* argument count from main */
  26         char    *const argv[],  /* argument vector from main */
  27         const FLASH char *optstring )           /* allowed args, e.g. "ab:c" */
  28 {
  29         static int      sp = 1;         /* position within argument */
  30         int             osp;            /* saved `sp' for param test */
  31         int             c;              /* option letter */
  32         const FLASH char *cp;           /* -> option in `optstring' */
  33
  34         optarg = NULL;
  35
  36         if ( sp == 1 )                  /* fresh argument */
  37         {
  38                 if ( optind >= argc             /* no more arguments */
  39                   || argv[optind][0] != '-'     /* no more options */
  40                   || argv[optind][1] == '\0'    /* not option; stdin */
  41                    )
  42                         return EOF;
  43         }
  44
  45         c = argv[optind][sp];           /* option letter */
  46         osp = sp++;                     /* get ready for next letter */
  47
  48         if ( argv[optind][sp] == '\0' ) /* end of argument */
  49         {
  50                 ++optind;               /* get ready for next try */
  51                 sp = 1;                 /* beginning of next argument */
  52         }
  53
  54         if ( c == ':'                   /* optstring syntax conflict */
  55           || (cp = strchr_P( optstring, c )) == NULL    /* not found */
  56            )
  57                 return '?';
  58
  59         if ( cp[1] == ':' )             /* option takes parameter */
  60         {
  61                 if ( osp != 1 )
  62                         return '?';
  63
  64                 if ( sp != 1 )          /* reset by end of argument */
  65                         return '?';
  66
  67                 if ( optind >= argc )
  68                         return '?';
  69
  70                 optarg = argv[optind];  /* make parameter available */
  71                 ++optind;               /* skip over parameter */
  72         }
  73
  74         return c;
  75 }
  76