In the following function:
char *mystrtok(const char *input, const char *delim,char *rest) { int i; for (i = 0; input[i] != *delim && input[i
you could also cast your 'input' variable with a (char*) type which would resolve the warning. just be careful using explicit casts like this so as not to modify constants themselves.
rest = (char*)input + i + 2;