This still doesn't only show only the unprinted lines from an execution before.

So, if I kill tail -f -n 50 access.log to do something, like edit a file, and run tail -f -n 50 access.log again, that will still show me 50 lines, where most, if not all, would probably be old.

If I killed python logscroll.py to do something else, and ran python logscroll.py again, it would show only the new lines since the time I killed it, whether that be 0 or 50.

I could've just stopped them instead of killing them, but it would still hold true if I needed to restart, logout, or lost the connection.

Running tail -f will probably be more than enough for most people, and I'm not saying this script is better. In fact, I'm pretty sure it's worse. It was just something I hacked together and thought that someone might find this useful.

tail -f blah.txt

the "-f" is follow, and updates as new stuff arrives in the file.

tail blah.txt
will show 10 lines by default once off.
tail -n 50 blah.txt
will do the same with 50 lines.

tail -f -n 50 blah.txt
Will follow the file after showing the first 50 lines.

There are some differences.

Tail shows the last 10 lines whenever you start, while this shows however many new lines there were since the last display.

Tail "monitors" the file, this just opens the file, goes to the pointer, and fires off whatever new lines are after.

Tail updates instantly, while this updates every 60 seconds.

Tail, I think, will only display the last 10 lines of every update. If you have a file that gets updated in batch, i.e. 50 lines a time like this server does, then you'll miss a lot of lines.

tail -f /var/log/apache2/access.log

updates whenever the file changes. AFAIK

Cheers,

David