Compilare: user.c: In function 'main': user.c:30: warning: format '%d' expects type 'int *', but argument 3 has type 'char *' user.c:36: warning: format '%d' expects type 'int *', but argument 3 has type 'char *' user.c:38: warning: implicit declaration of function 'exit' user.c:38: warning: incompatible implicit declaration of built-in function 'exit'