Compilare: user.c: In function ‘main’: user.c:20:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("texttrim.in","r",stdin); ^ user.c:21:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("texttrim.out","w",stdout); ^ user.c:24:14: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&cost[i]); ^ user.c:28:10: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%c",&ch); ^ user.c:29:9: warning: ignoring return value of ‘gets’, declared with attribute warn_unused_result [-Wunused-result] gets(sir); ^ user.c:32:10: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&w); ^ /tmp/ccZqkWMc.o: In function `main': user.c:(.text.startup+0x94): warning: the `gets' function is dangerous and should not be used.