Compilare: user.c: In function ‘headers’: user.c:21:8: warning: ignoring return value of ‘fgets’, declared with attribute warn_unused_result [-Wunused-result] fgets(buffer, 1024, f); ^ user.c: In function ‘main’: user.c:108:9: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("convertor.out", "w", stdout); ^ In file included from /usr/include/stdio.h:934:0, from user.c:1: In function ‘fgets’, inlined from ‘headers’ at user.c:21:8: /usr/include/i386-linux-gnu/bits/stdio2.h:253:2: warning: call to ‘__fgets_chk_warn’ declared with attribute warning: fgets called with bigger size than length of destination buffer [enabled by default] return __fgets_chk_warn (__s, __bos (__s), __n, __stream); ^