“assignment discards 'const' qualifier” error on non-const pointer

Question

In the following function:

char *mystrtok(const char *input, const char *delim,char *rest) {
    int i;
    for (i = 0; input[i] != *delim && input[i         


        

Answer 1

change the prototype to

char *mystrtok(const char *input, const char *delim, const char *rest);

Answer 2

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;

Answer 3

input is a pointer to a constant char, and you're assigning it to a pointer to a non-constant char. This here might be an interesting reading for you.