Compilare: user.c: In function ‘main’: user.c:46:3: warning: implicit declaration of function ‘strdup’ [-Wimplicit-function-declaration] p=strdup(c); ^ user.c:46:4: warning: assignment makes pointer from integer without a cast [enabled by default] p=strdup(c); ^ user.c:45:8: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result] fread(&c, 1, 1024, in); ^