/* getopt.c -- command line option/argument parser.
*  From AT&T UNIX System Toolchest
*/

#define  DOS_MODS

#if defined (DOS_MODS)
   /* Program name set by main() */
   extern char *Pgm;
#else
#ident "@(#)getopt.c   1.9"
#endif

/*     3.0 SID #      1.2"     */
/* LINTLIBRARY */
#define  NULL  0
#define  EOF   (-1)
#define  ERR(s, c)   if(opterr){\
         char errbuf[2];\
         errbuf[0] = c; errbuf[1] = '\n';\
         (void) write(2, argv[0], (unsigned)strlen(argv[0]));\
         (void) write(2, s, (unsigned)strlen(s));\
         (void) write(2, errbuf, 2);}

#if defined (DOS_MODS)
/* permit funtion prototyping under DOS */
#include <stdlib.h>
#include <string.h>
#else
/* standard UNIX declarations */
extern int strcmp();
extern char *strchr();
/*
*     The following line was moved here from the ERR definition to
*     prevent a "duplicate definition" error message when the code
*     is compiled under DOS.
*/
extern int strlen(), write();
#endif

int   opterr = 1;
int   optind = 1;
int   optopt;
char  *optarg;

int   getopt(argc, argv, opts)
int   argc;
char **argv, *opts;
   {
   static int sp = 1;
   register int c;
   register char *cp;
   if(sp == 1)
      if(optind >= argc ||
         argv[optind][0] != '-' || argv[optind][1] == '\0')
            return(EOF);
      else if(strcmp(argv[optind], "--") == NULL)
         {
         optind++;
         return(EOF);
         }
   optopt = c = argv[optind][sp];
   if(c == ':' || (cp = strchr(opts, c)) == NULL)
      {
      ERR(": illegal option -- ", c);
      if(argv[optind][++sp] == '\0')
         {
         optind++;
         sp = 1;
         }
      return('?');
      }
   if(*++cp == ':')
      {
      if(argv[optind][sp+1] != '\0')
         optarg = &argv[optind++][sp+1];
      else
         if(++optind >= argc)
            {
            ERR(": option requires an argument -- ", c);
            sp = 1;
            return('?');
            }
         else
            optarg = argv[optind++];
      sp = 1;
      }
   else
      {
      if(argv[optind][++sp] == '\0')
         {
         sp = 1;
         optind++;
         }
      optarg = NULL;
      }
   return(c);
   }