/in/foo.c: In function 'main':
/in/foo.c:8:2: error: too many arguments to function 'getchar'
  getchar(ch);
  ^~~~~~~
In file included from /usr/include/stdio.h:935:0,
                 from /in/foo.c:1:
/usr/include/x86_64-linux-gnu/bits/stdio.h:44:1: note: declared here
 getchar (void)
 ^~~~~~~