Compilare: user.c: In function ‘main’: user.c:9:9: warning: unused variable ‘len’ [-Wunused-variable] int len=0; ^ user.c:11:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("dinozaur.in","r",stdin); ^ user.c:12:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("dinozaur.out","w",stdout); ^ user.c:15:14: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%c",&ch); ^