*}
codea teams

String Upper, String Lower



Convert the characters in a string to upper case or lower case

char *strupr(char *string)
{
    if (NULL == string)
        return NULL;

    char *s;

    for (s = string; *s; ++s)
    {
        if (*s >= 'a' && *s <= 'z')
        {
            *s = toupper(*s);
        }
    }

    return string;
} 

char *strlwr(char *string)
{
    if (NULL == string)
        return NULL;

    char *s;

    for (s = string; *s; ++s)
        *s = tolower(*s);

    return string;
}