getopt.c

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/*
 * This is an unpublished work copyright (c) 1998 HELIOS Software GmbH
 * 30827 Garbsen, Germany
 */
 
 
#include <stdio.h>
#include <string.h>
#ifdef HAS_UNISTD
# include <unistd.h>
#endif
 
char *optarg;
int optind = 1;
int opterr = 1;
int optopt;
static int subopt;
static int suboptind = 1;
 
int getopt(int argc, char *const argv[], const char * optstring)
{
    char *curopt;
    char *p;
    int cursubopt;
 
    if (suboptind == optind-1 && argv[suboptind][subopt] != '\0') {
        curopt = (char *)argv[suboptind];
    } else {
        curopt = (char *)argv[optind];
        if (curopt == NULL || curopt[0] != '-' || strcmp(curopt, "-") == 0)
            return -1;
        suboptind = optind;
        subopt = 1;
        optind++;
        if (strcmp(curopt, "--") == 0)
            return -1;
    }
    cursubopt = subopt++;
    if ((p = strchr(optstring, curopt[cursubopt])) == NULL) {
        optopt = curopt[cursubopt];
        if (opterr)
            fprintf(stderr, "%s: illegal option -- %c\n", argv[0], optopt);
        return '?';
    }
    if (p[1] == ':') {
        if (curopt[cursubopt+1] != '\0') {
            optarg = curopt+cursubopt+1;
            suboptind++;
            return p[0];
        }
        if (argv[optind] == NULL) {
            optopt = p[0];
            if (opterr)
                fprintf(stderr, "%s: option requires an argument -- %c\n", argv[0], optopt);
            if (*optstring == ':')
                return ':';
            return '?';
        }
        optarg = argv[optind++];
    }
    return p[0];
}