usr/src/lib/libc/stdlib/getsubopt.c

/*-
 * Copyright (c) 1990, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * %sccs.include.redist.c%
 */

#ifndef lint
static char sccsid[] = "@(#)getsubopt.c 8.1 (Berkeley) %G%";
#endif /* not lint */

#include <unistd.h>
#include <stdlib.h>

/*
 * The SVID interface to getsubopt provides no way of figuring out which
 * part of the suboptions list wasn't matched.  This makes error messages
 * tricky...  The extern variable suboptarg is a pointer to the token
 * which didn't match.
 */
char *suboptarg;

getsubopt(optionp, tokens, valuep)
        register char **optionp, **valuep;
        register char * const *tokens;
{
        register int cnt;
        register char *p;

        suboptarg = *valuep = NULL;

        if (!optionp || !*optionp)
                return(-1);

        /* skip leading white-space, commas */
        for (p = *optionp; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);

        if (!*p) {
                *optionp = p;
                return(-1);
        }

        /* save the start of the token, and skip the rest of the token. */
        for (suboptarg = p;
            *++p && *p != ',' && *p != '=' && *p != ' ' && *p != '\t';);

        if (*p) {
                /*
                 * If there's an equals sign, set the value pointer, and
                 * skip over the value part of the token.  Terminate the
                 * token.
                 */
                if (*p == '=') {
                        *p = '\0';
                        for (*valuep = ++p;
                            *p && *p != ',' && *p != ' ' && *p != '\t'; ++p);
                        if (*p)
                                *p++ = '\0';
                } else
                        *p++ = '\0';
                /* Skip any whitespace or commas after this token. */
                for (; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
        }

        /* set optionp for next round. */
        *optionp = p;

        for (cnt = 0; *tokens; ++tokens, ++cnt)
                if (!strcmp(suboptarg, *tokens))
                        return(cnt);
        return(-1);
}