#include <stdio.h>
#include <string.h>

char* mytok(char *str, const char* delim) {
    static char* x;
    if(str != NULL)
        x = str;
    if(x[0] == '\0')
        return NULL;

    char *ans = x, *b;
    const char *d;

    for(b = x; *b !='\0'; b++) {
        for(d = delim; *d != '\0'; d++) {
            if(*b == *d) {
                *b = '\0';
                x = b+1;
                if(b == ans) {
                    ans++;
                    continue;
                }
                return ans;
            }
        }
    }

    return ans;
}

int main(void)
{
    char str1[80] = "abcd-efg-hij";
    char str2[80] = "*klm-n*opq-rst";
    char s1[5] = "-";
    char s2[5] = "*-";
    char *token;
    token = mytok(str1, s1);
    puts(token);
    token = mytok(NULL, s1);
    puts(token);
    token = mytok(str2, s2);
    puts(token);
    token = mytok(NULL, s2);
    puts(token);
    token = mytok(NULL, s2);
    puts(token);
    token = mytok(NULL, s2);
    puts(token);
}