title: C - Check if given argument is natural number
body: <p>How should I correctly <strong>check if given argument is a</strong> <strong>natural number</strong> in C? I am a very beginner when it comes to C... I already have compared that argument to 1 and 2 by atoi(argv[1]) == 1 ..., but when I pass let's say 1.2137 as an argument, atoi cuts it to 1.
  Thanks for any help.</p>