Compilare: user.c: In function ‘main’: user.c:9:12: warning: implicit declaration of function ‘euclid’ [-Wimplicit-function-declaration] int rez = euclid(a,b); ^~~~~~ user.c:6:2: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fp,"%d", &a); ^~~~~~~~~~~~~~~~~~~ user.c:7:5: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fp,"%d", &b); ^~~~~~~~~~~~~~~~~~~