Compilare: user.cpp: In function ‘int main()’: user.cpp:17:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("strmatch.in","r",stdin); ^ user.cpp:18:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("strmatch.out","w",stdout); ^ user.cpp:19:12: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(a); ^ user.cpp:20:12: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(c); ^ /tmp/cct3sV1V.o: In function `main': user.cpp:(.text.startup+0x5b): warning: the `gets' function is dangerous and should not be used.