Compilare: user.c:8: warning: return type of ‘main’ is not ‘int’ user.c: In function ‘main’: user.c:9: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result user.c:10: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result user.c:11: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result user.c:14: warning: ignoring return value of ‘gets’, declared with attribute warn_unused_result /tmp/ccWIaXdW.o: In function `main': user.c:(.text+0x9c): warning: the `gets' function is dangerous and should not be used.