Description

   The getc macro returns the next byte from the input stream
   specified by the file_ptr parameter and moves the file pointer,
   if defined, ahead one byte in the input stream.

   Since getc is a macro, a file pointer argument with side effects
   (for example, getc (*f++)) might be evaluated incorrectly.
   In such a case, use the fgetc function instead. See the fgetc
   function.

   See also getc_unlocked.