strcmp.c

int		ft_strcmp(const char *s1, const char *s2)
{
	int i;

	i = 0;
	while (s1[i] || s2[i])
	{
		if (s1[i] != s2[i])
			return ((unsigned char)s1[i] - (unsigned char)s2[i]);
		++i;
	}
	return (0);
}

#include <stdio.h>
#include<string.h>

int ft_strcmp(const char *s1, const char *s2);

int main()
{
    char *s1 = "\0";
    char *s2 = "\200";

    int i1 = strcmp(s1, s2);
    int i2 = ft_strcmp(s1, s2);

    char    *s3 = "\x12\xff\x65\x12\xbd\xde\xad";
    char    *s4 = "\x12\x02";

    int     i3 = strcmp(s3, s4);
    int     i4 = ft_strcmp(s3, s4);

    printf("strcmp: %d\nft_strcmp: %d\nstrcmp: %d\nft_strcmp: %d\n", i1, i2, i3\
, i4);
    return 0;
}

int		ft_strcmp(const char *s1, const char *s2)
{
	int i;

	i = 0;
	while (s1[i] || s2[i])
	{
		if (s1[i] != s2[i])
			return ((unsigned char)s1[i] - (unsigned char)s2[i]);
		++i;
	}
	return (0);
}