Compilare: user.c: In function ‘main’: user.c:9:10: warning: unused variable ‘c’ [-Wunused-variable] char c; ^ user.c:7:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("paranteze2.in","r",stdin); ^ user.c:8:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("paranteze2.out","w",stdout); ^ user.c:10:9: warning: ignoring return value of ‘gets’, declared with attribute warn_unused_result [-Wunused-result] gets(s); ^ /tmp/ccRtAg2F.o: In function `main': user.c:(.text.startup+0x5b): warning: the `gets' function is dangerous and should not be used.