string handling

char *strcpy(char *dst, const char *src)
{
    char *cp = dst;
    while (*cp++ = *src++);
    return dst;
}

 

char *strncpy(char *dest, const char *source, size_t count)
{
    char *start = dest;

    while (count && (*dest++ = *source++)) count--;
    if (count) while (--count) *dest++ = '\0';
    return start;
}

 

char *strcat(char *dst, const char *src)
{
    char *cp = dst;
    while (*cp) cp++;
    while (*cp++ = *src++);
    return dst;
}

 

size_t strlen(const char * str)
{
  const char *s;
  for(s = str ; *s ; ++s);
  return (s - str);
}

 

size_t strlen(const char * str)
{
  const char *s = str;
  while(*s++);
  return s-str-1;
}