commands/cawf/getopt.c

   1 /*
   2 Newsgroups: mod.std.unix
   3 Subject: public domain AT&T getopt source
   4 Date: 3 Nov 85 19:34:15 GMT
   5
   6 Here's something you've all been waiting for:  the AT&T public domain
   7 source for getopt(3).  It is the code which was given out at the 1985
   8 UNIFORUM conference in Dallas.  I obtained it by electronic mail
   9 directly from AT&T.  The people there assure me that it is indeed
  10 in the public domain.
  11 */
  12
  13
  14 /*LINTLIBRARY*/
  15 #define NULL    0
  16 #define EOF     (-1)
  17 #define ERR(s, c)       if(opterr){\
  18         extern int strlen(), write();\
  19         char errbuf[2];\
  20         errbuf[0] = c; errbuf[1] = '\n';\
  21         (void) write(2, argv[0], (unsigned)strlen(argv[0]));\
  22         (void) write(2, s, (unsigned)strlen(s));\
  23         (void) write(2, errbuf, 2);}
  24
  25 extern int strcmp();
  26 extern char *strchr();
  27
  28 int     opterr = 1;
  29 int     optind = 1;
  30 int     optopt;
  31 char    *optarg;
  32
  33 int
  34 getopt(argc, argv, opts)
  35 int     argc;
  36 char    **argv, *opts;
  37 {
  38         static int sp = 1;
  39         register int c;
  40         register char *cp;
  41
  42         if(sp == 1)
  43                 if(optind >= argc ||
  44                    argv[optind][0] != '-' || argv[optind][1] == '\0')
  45                         return(EOF);
  46                 else if(strcmp(argv[optind], "--") == NULL) {
  47                         optind++;
  48                         return(EOF);
  49                 }
  50         optopt = c = argv[optind][sp];
  51         if(c == ':' || (cp=strchr(opts, c)) == NULL) {
  52                 ERR(": illegal option -- ", c);
  53                 if(argv[optind][++sp] == '\0') {
  54                         optind++;
  55                         sp = 1;
  56                 }
  57                 return('?');
  58         }
  59         if(*++cp == ':') {
  60                 if(argv[optind][sp+1] != '\0')
  61                         optarg = &argv[optind++][sp+1];
  62                 else if(++optind >= argc) {
  63                         ERR(": option requires an argument -- ", c);
  64                         sp = 1;
  65                         return('?');
  66                 } else
  67                         optarg = argv[optind++];
  68                 sp = 1;
  69         } else {
  70                 if(argv[optind][++sp] == '\0') {
  71                         sp = 1;
  72                         optind++;
  73                 }
  74                 optarg = NULL;
  75         }
  76         return(c);
  77 }