Compilare: user.c: In function ‘main’: user.c:28:5: warning: format ‘%ld’ expects argument of type ‘long int’, but argument 3 has type ‘int’ [-Wformat=] fprintf(po,"%ld",cmmdc(a,b)); ^ user.c:25:11: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(pf,"%ld",&a); ^ user.c:26:11: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(pf,"%ld",&b); ^