Compilare: user.c: In function ‘main’: user.c:24:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("strmatch.in", "r", stdin); ^ user.c:25:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("strmatch.out", "w", stdout); ^ user.c:27:11: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%s", str_a); ^ user.c:28:11: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%s", str_b); ^