Both view and pipe the file without saving to disk

cat /path/to/some/file.txt | tee /dev/pts/0 | wc -l
This is a cool trick to view the contents of the file on /dev/pts/0 (or whatever terminal you're using), and also send the contents of that file to another program by way of an unnamed pipe. All the while, you've not bothered saving any extra data to disk, like you might be tempted to do with sed or grep to filter output.

By: atoponce
2009-11-07 22:24:28

What Others Think

Use '/dev/tty': it was designed for this purpose. The device 'tty' always points to the process' controlling terminal device. In your example, /dev/tty would internally point to /dev/pts/0.
arcege · 665 weeks and 1 day ago
Ahh, I didn't know that. That's good to know. Also, after posting this, I realized later that I'm using 'cat' when I don't need to. Rather: tee /dev/tty < /path/to/some/file | wc -l would be more appropriate.
atoponce · 665 weeks and 1 day ago

What do you think?

Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?

You must be signed in to comment.

What's this? is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

Share Your Commands

Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.


Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for: