The C language doesn't implement strings.  However, there is
a convention used by all C code that a string is an consecutive sequence
of bytes terminated by a zero character ('\0').

This code uses some of the string functions.  Note that one very useful
one is GNU specific, and might not be available on on *nix systems.

This code also has a memory leak.  Can you spot it?
   $ valgrind ./a.out
will help you find it.