문자열 조작함수

[code]size_t strlen(const char *s)
{
    size_t n;
    for(n=0; *s!='\0'; ++s)
        ++n;

    return n;
}

char *strcpy(char *s1, register const char *2)
{
    register char *p = s1;
    while(*p++ *s2++);
    
    return s1;
}

char *strcat(char *s1, register const char *s2)
{
    register char *p = s1;

    while(*p)
        ++p;
    while(*p++ = *s2++);

    return s1;
}[/code]