Eroare de compilare: user.c: In function ‘main’: user.c:15: warning: implicit declaration of function ‘freeopen’ user.c:17: warning: format ‘%d’ expects type ‘int *’, but argument 2 has type ‘int’ user.c:19: warning: format ‘%d’ expects type ‘int *’, but argument 2 has type ‘int’ user.c:19: warning: format ‘%d’ expects type ‘int *’, but argument 3 has type ‘int’ user.c:17: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result user.c:19: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result user.c:17: warning: ‘n’ is used uninitialized in this function user.c:19: warning: ‘a’ may be used uninitialized in this function user.c:19: warning: ‘b’ may be used uninitialized in this function /tmp/ccpyldc7.o: In function `main': user.c:(.text+0x52): undefined reference to `freeopen' user.c:(.text+0x6f): undefined reference to `freeopen' collect2: ld returned 1 exit status