citix:/home/xitron/C# cat hello.c 
#include <stdio.h>

main()
{
        printf("Hello, World\n");
}
error:
citix:/home/xitron/C# gcc hello.c 
hello.c:1:19: error: stdio.h: No such file or directory
hello.c: In function ‘main’:
hello.c:5: warning: incompatible implicit declaration of built-in function ‘printf’