/* getopt.c
 * last update: 9, August, 1995.
 *
 * getopt for non-Unix
 *
 * Copyright (C) 1995 All rights reserved.
 * written by Gyudong Kim(chilly@iclab.snu.ac.kr)
 * set tabstop=5
 *
 * No warranty on the functions of these routines are provided.
 * This is written simply for mimicking Unix getopt(3).
 *
 */
#include <stdio.h>

#define DIRDEL '\\'

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

static char *cmdname = NULL;

static void opt_error(opt)
char opt;
{
	if (!opterr) return;
	(void)fprintf(stderr,
		"%s: illegal option -- %c\n",cmdname,opt);
}

static void opt_needs_arg(opt)
char opt;
{
	if (!opterr) return;
	(void)fprintf(stderr,
		"%s: option requires an argument -- %c\n",cmdname,opt);
}

int getopt(argc,argv,options)
int argc;
char **argv,*options;
{
	static char *curptr=NULL;
	int curoption = '?';
	char *opts;

	if (optind>argc) return(-1);
	if (argv[optind][0]=='-') {
		if (curptr==NULL) curptr=(argv[optind])+1;
	} else return(-1);

	if (!curptr[0]) return('-');	/* '-' is a valid option */
	
	if (curptr[0]=='-') {		/* '--' should terminate option proc. */
		optind++;
		return(-1);
	}

	if (cmdname==NULL) cmdname=basename(argv[0]);
	if (curptr[0]==':') {		/* ':' can not be a valid option. why ? */
		opt_error(curptr[0]);
		return(curoption);
	} 

	for(opts=options;opts[0];opts++) {
		if (curptr[0]!=opts[0]) continue;
		curoption=curptr[0];
		if (opts[1]==':') {
			optarg=curptr+1;
			if (!optarg[0]) {
				optind++;
				optarg=argv[optind];
			}
			if (optarg==NULL) {
				opt_needs_arg(curptr[0]);
				return('?');
			}
			optind++;
		} else {
			optarg="";
			curptr++;
			if (!curptr[0]) {
				curptr=(char *)NULL;
				optind++;
			}
		}
		return(curoption);
	}
	opt_error(curptr[0]);
	return(curoption);
}
/* getopt.c */