wheel.c

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

void wheel(char name[])
{
    char *track = malloc(strlen(name));
    int i, ii;
    for (i = 0, ii = strlen(name) + 1; i < ii; i++) {
        printf("%s:wheel:%s\n", track, name);
        strcat(track, "_");
        name++;
    }
    free(track);
}

int main(int argc, char *argv[])
{
    if (argc < 2)
        printf("usage: wheel [name]\n");
    else
        wheel(argv[1]);
    return 0;
}