[user02@FC4 Lesson01]$ vi demo.c
[user02@FC4 Lesson01]$ cat -n demo.c

   1  #include <stdio.h>
   2
   3  int main(void)
   4  {
   5     printf("This is a sample C program!\n");
   6
   7     return 0;
   8  }

[user02@FC4 Lesson01]$ gcc -o demo demo.c
[user02@FC4 Lesson01]$ ./demo
This is a sample C program!
[user02@FC4 Lesson01]$