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

   1 #ifndef GETOPT_H
   2 #define GETOPT_H
   3
   4 /* implements UNIX-style getopt
   5
   6         The example below shows typical usage.  The third argument is a string of
   7         option letters.  If an option letter is followed by ':' it takes an
   8         argument.  Getopt returns the option letter if it finds one; if the option
   9         specified is illegal, it prints an error message and returns '?'.  When
  10         no more options are found, it returns -1.  Optind always points to the
  11         next argument in the option list.  For options which take an argument,
  12         optarg points to the argument (see -c in the example).
  13
  14         An option of "-" (single dash) signifies the end of the option list, and
  15         causes getopt to return -1.  This is useful for specifying filenames
  16         which start with a dash.
  17
  18         This version of getopt recognizes options which begin with '-', but also
  19         recognizes '/' as an option switch (per NT usage).  Options which don't
  20         require an argument may be stacked on the command line.  Valid options
  21         using the example below:
  22
  23                 myprogram -a -b
  24                 myprogram -ab
  25                 myprogram -c file1 -ac file2
  26                 myprogram -c:file
  27
  28         As shown in the example, this version of getopt allows a ':' to be placed
  29         between the option letter and its argument.
  30
  31 EXAMPLE:
  32
  33         #include <stdio.h>
  34         #include "getopt.h"
  35         main(int argc, char **argv)
  36         {
  37                 int c;
  38                 while ((c=getopt(argc, argv, "abc:")) != -1) {
  39                         switch (c) {
  40                         case 'a': printf("got -a\n"); break;
  41                         case 'b': printf("got -b\n"); break;
  42                         case 'c': printf("got -c = %s\n", optarg); break;
  43                         case '?': printf(); exit(1);
  44                         }
  45                 }
  46                 for ( ; optind < argc; optind++)
  47                         process_file(argv[optind]);
  48         }
  49
  50 */
  51
  52 int getopt(int argc, char ** argv, char *opt);
  53
  54 extern int   optind;    /* current argc index into arglist */
  55 extern char *optarg;    /* argument string for options that take an argument */
  56 extern int   opterr;    /* set to 1 if error condition, 0 otherwise; */
  57                         /* useful for using '?' as an option */
  58
  59 #endif