/* Copyright (C) 1994 DJ Delorie, see COPYING.DJ for details */
#include <string.h>

char* strtok(char* s, const char* delim)
{
    const char* spanp;
    int c, sc;
    char* tok;
    static char* last;

    if (s == NULL && (s = last) == NULL)
        return (NULL);

    /*
     * Skip (span) leading delimiters (s += strspn(s, delim), sort of).
     */
cont:
    c = *s++;
    for (spanp = delim; (sc = *spanp++) != 0;) {
        if (c == sc)
            goto cont;
    }

    if (c == 0) { /* no non-delimiter characters */
        last = NULL;
        return (NULL);
    }
    tok = s - 1;

    /*
     * Scan token (scan for delimiters: s += strcspn(s, delim), sort of).
     * Note that delim must have one NUL; we stop if we see that, too.
     */
    for (;;) {
        c = *s++;
        spanp = delim;
        do {
            if ((sc = *spanp++) == c) {
                if (c == 0)
                    s = NULL;
                else
                    s[-1] = 0;
                last = s;
                return (tok);
            }
        } while (sc != 0);
    }
    /* NOTREACHED */
}