Case Insensitive String comp in C

Question

I have two postcodes char* that I want to compare, ignoring case. Is there a function to do this?

Or do I have to loop through each use the tolower func

Answer 1

There is no function that does this in the C standard. Unix systems that comply with POSIX are required to have strcasecmp in the header strings.h; Microsoft systems have stricmp. To be on the portable side, write your own:

int strcicmp(char const *a, char const *b)
{
    for (;; a++, b++) {
        int d = tolower((unsigned char)*a) - tolower((unsigned char)*b);
        if (d != 0 || !*a)
            return d;
    }
}

But note that none of these solutions will work with UTF-8 strings, only ASCII ones.