Compilare: user.c: In function ‘main’: user.c:38:5: warning: implicit declaration of function ‘strdup’ [-Wimplicit-function-declaration] p = strdup(str); ^ user.c:38:7: warning: assignment makes pointer from integer without a cast [enabled by default] p = strdup(str); ^ user.c:40:7: warning: assignment makes pointer from integer without a cast [enabled by default] s = strdup(str); ^