strdup() - what does it do in C?

Question

What is the purpose of the strdup() function in C?

Answer 1

char * strdup(const char * s)
{
  size_t len = 1+strlen(s);
  char *p = malloc(len);

  return p ? memcpy(p, s, len) : NULL;
}

Maybe the code is a bit faster than with strcpy() as the \0 char doesn't need to be searched again (It already was with strlen()).