workbench/network/stacks/AROSTCP/netlib/getopt.c

   1 /* $Id$
   2  *
   3  *      getopt.c - Unix compatible command line option parsing
   4  */
   5
   6 /*
   7 **      @(#)getopt.c    2.5 (smail) 9/15/87
   8 */
   9
  10 /*
  11  * Here's something you've all been waiting for:  the AT&T public domain
  12  * source for getopt(3).  It is the code which was given out at the 1985
  13  * UNIFORUM conference in Dallas.  I obtained it by electronic mail
  14  * directly from AT&T.  The people there assure me that it is indeed
  15  * in the public domain.
  16  *
  17  * There is no manual page.  That is because the one they gave out at
  18  * UNIFORUM was slightly different from the current System V Release 2
  19  * manual page.  The difference apparently involved a note about the
  20  * famous rules 5 and 6, recommending using white space between an option
  21  * and its first argument, and not grouping options that have arguments.
  22  * Getopt itself is currently lenient about both of these things White
  23  * space is allowed, but not mandatory, and the last option in a group can
  24  * have an argument.  That particular version of the man page evidently
  25  * has no official existence, and my source at AT&T did not send a copy.
  26  * The current SVR2 man page reflects the actual behavor of this getopt.
  27  * However, I am not about to post a copy of anything licensed by AT&T.
  28  */
  29
  30 #include <stdlib.h>
  31 #include <string.h>
  32 #include <stdio.h>
  33
  34 /*LINTLIBRARY*/
  35 #define ERR(s, c)\
  36   if(opterr) { fprintf(stderr, "%s%s%lc\n", argv[0], s, c); }
  37
  38 int     opterr = 1;
  39 int     optind = 1;
  40 int     optopt;
  41 char    *optarg;
  42
  43 /*
  44  * Using the 'const' on the argv below increases code size on SAS/C 6.51 by
  45  * 24 bytes, even when it should have no effect on the generated code!
  46  */
  47 int
  48 getopt(int argc, char * /*const*/ argv[], char const *opts)
  49 {
  50         static int sp = 1;
  51         register int c;
  52         register char *cp;
  53
  54         if(sp == 1)
  55                 if(optind >= argc ||
  56                    argv[optind][0] != '-' || argv[optind][1] == '\0')
  57                         return(EOF);
  58                 else if(strcmp(argv[optind], "--") == NULL) {
  59                         optind++;
  60                         return(EOF);
  61                 }
  62         optopt = c = argv[optind][sp];
  63         if(c == ':' || (cp=index(opts, c)) == NULL) {
  64                 ERR(": illegal option -- ", c);
  65                 if(argv[optind][++sp] == '\0') {
  66                         optind++;
  67                         sp = 1;
  68                 }
  69                 return('?');
  70         }
  71         if(*++cp == ':') {
  72                 if(argv[optind][sp+1] != '\0')
  73                         optarg = &argv[optind++][sp+1];
  74                 else if(++optind >= argc) {
  75                         ERR(": option requires an argument -- ", c);
  76                         sp = 1;
  77                         return('?');
  78                 } else
  79                         optarg = argv[optind++];
  80                 sp = 1;
  81         } else {
  82                 if(argv[optind][++sp] == '\0') {
  83                         sp = 1;
  84                         optind++;
  85                 }
  86                 optarg = NULL;
  87         }
  88         return(c);
  89 }