Eroare de compilare: user.c: In function ‘main’: user.c:19:5: warning: implicit declaration of function ‘fileopen’ [-Wimplicit-function-declaration] f=fileopen("reactivi.in","r"); ^ user.c:19:6: warning: assignment makes pointer from integer without a cast [enabled by default] f=fileopen("reactivi.in","r"); ^ user.c:20:6: warning: assignment makes pointer from integer without a cast [enabled by default] g=fileopen("reactivi.out","w"); ^ /tmp/cckIDn7W.o: In function `main': user.c:(.text.startup+0x23): undefined reference to `fileopen' user.c:(.text.startup+0x3d): undefined reference to `fileopen' collect2: error: ld returned 1 exit status