ed (thing)

ed is quite possibly the oldest and most feared/worshipped text editor in existance (though ed's standing as a text editor is highly debated). Anyone who can actually use ed is treated as a god. Then again, anyone who can use ed /is/ a god.

Here, for your scrutiny, is a copy of the source code for ed:

#include 

int main( void )
{
    char *strin;
    for(;;)
    {
        printf( "- " );
        scanf( "%s", strin );
        printf( "?\n" );
    }
}