Compilare: user.c: In function ‘main’: user.c:12:5: warning: implicit declaration of function ‘close’ [-Wimplicit-function-declaration] close(in); ^ user.c:5:9: warning: unused variable ‘cmmdc’ [-Wunused-variable] int cmmdc = 0; ^ user.c:9:11: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d", &a); ^ user.c:10:11: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d", &b); ^