Compilare: user.c: In function ‘main’: user.c:6:9: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("strmatch.in","r",stdin),freopen("strmatch.out","w",stdout),fgets(s,sizeof(s),stdin),fgets(u,sizeof(u),stdin),m=strlen(s),n=strlen(u); ^ user.c:6:42: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("strmatch.in","r",stdin),freopen("strmatch.out","w",stdout),fgets(s,sizeof(s),stdin),fgets(u,sizeof(u),stdin),m=strlen(s),n=strlen(u); ^ user.c:6:75: warning: ignoring return value of ‘fgets’, declared with attribute warn_unused_result [-Wunused-result] freopen("strmatch.in","r",stdin),freopen("strmatch.out","w",stdout),fgets(s,sizeof(s),stdin),fgets(u,sizeof(u),stdin),m=strlen(s),n=strlen(u); ^ user.c:6:100: warning: ignoring return value of ‘fgets’, declared with attribute warn_unused_result [-Wunused-result] freopen("strmatch.in","r",stdin),freopen("strmatch.out","w",stdout),fgets(s,sizeof(s),stdin),fgets(u,sizeof(u),stdin),m=strlen(s),n=strlen(u); ^