一次局域网入侵全过程

Since I have spent a long time with Java, I tend to think in Java way even when I am playing with C/C++.

 

GCC allows function declarations without an implementation.

 

#include <stdio.h>
int def(int);
int abc(int one) {
return one+1;
}
int main(void) {
printf("The number is %d\n", abc(0));
}

 

Compile and run it:

 

jing@jingguolin:~/test$ gcc foo.c

jing@jingguolin:~/test$ ./a.out

The number is 1