Problem:
You have C code like
fprintf(stderr, "test");
but when you try to compile it you see an error message like
/home/uli/myproject/main.c:9:25: error: ‘stderr’ undeclared (first use in this function) fprintf(stderr, "test");
Solution:
Add
#include <stdio.h>
at the top of the source file where the error occured. Including stdio.h
will include symbols like printf
, fprintf
, stdin
, stdout
and stderr
.