C语言不区分大小写比较字符串函数

C语言不区分大小写比较字符串函数

int my_stricmp(const char *s1, const char *s2) 
{
    
    
    int i = 0;
    while(s1[i] != '\0' && s2[i] != '\0') 
    {
    
    
        if(s1[i] >= 'a' && s1[i] <= 'z')
            s1[i] -= 32;
        else if(s2[i] >= 'a' && s2[i] <= 'z')
            s2[i] -= 32;
        if(s1[i] < s2[i])
            return -1;
        else if(s1[i] > s2[i])
            return 1;
        i++;
    }
    if(strlen(s1) < strlen(s2))
        return -1;
    else if(strlen(s1) > strlen(s2))
        return 1;
    else
        return 0;
}