Compilare: user.c: In function ‘main’: user.c:22: warning: implicit declaration of function ‘strlen’ user.c:22: warning: incompatible implicit declaration of built-in function ‘strlen’ user.c:12: warning: unused variable ‘c’ user.c:15: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result user.c:25: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result