Redirect STDIN

< /path/to/file.txt grep foo
Several times, I find myself hitting my up arrow, and changing the search term. Unfortunately, I find myself wasting too much time typing: grep kernel /var/log/messages Redirecting STDIN allows me to put the search term at the end so I less cursor movement to change what I'm searching for: < /var/log/messages grep kernel If you're using the emacs keyboard binding, then after you press your up arrow, press CTRL+w to erase the word. If this has already been submitted, I couldn't find it with the search utility.

By: atoponce
2009-03-29 02:43:40

What Others Think

very nice. I had not thought of that
GNUix · 621 weeks and 4 days ago
This is very nice. I had always used cat file|grep foo for easy editing. Good to know there's a better syntax.
clockworkavian · 621 weeks and 4 days ago
grep foo
jnash · 621 weeks and 4 days ago
I wanted to say: grep foo
jnash · 621 weeks and 4 days ago
Oh well.. looks like theres some garbling of comments. (here goes) I wanted to say: grep foo "lessthan"(cat file)
jnash · 621 weeks and 4 days ago
clockworkavian: using grep with cat like that is highly discouraged, as it (needlessly) invokes cat. I like the suggestion for redirecting stdin.
kaedenn · 621 weeks and 3 days ago
@kaedenn I know it's discouraged, as grep can do it natively, but for long filenames, having to hit the arrow keys a bunch of times to change a search term is a pain. I will follow the correct way when it involves less work (the redirection is acceptable), but when it involves more work, I think I'll do it wrong and cut down the RSI
clockworkavian · 621 weeks and 2 days 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: