Hide

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again.

Delete that bloated snippets file you've been using and share your personal repository with the world. 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.


If you have a new feature suggestion or find a bug, please get in touch via http://commandlinefu.uservoice.com/

Get involved!

You can sign-in using OpenID credentials, or register a traditional username and password.

First-time OpenID users will be automatically assigned a username which can be changed after signing in.

Hide

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.

» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10

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:

Hide

News

2011-03-12 - Confoo 2011 presentation
Slides are available from the commandlinefu presentation at Confoo 2011: http://presentations.codeinthehole.com/confoo2011/
2011-01-04 - Moderation now required for new commands
To try and put and end to the spamming, new commands require moderation before they will appear on the site.
2010-12-27 - Apologies for not banning the trolls sooner
Have been away from the interwebs over Christmas. Will be more vigilant henceforth.
2010-09-24 - OAuth and pagination problems fixed
Apologies for the delay in getting Twitter's OAuth supported. Annoying pagination gremlin also fixed.
Hide

Tags

Hide

Functions

Commands tagged delay from sorted by
Terminal - Commands tagged delay - 4 results
sudo tc qdisc add dev lo root netem delay 500ms
2012-11-05 05:29:51
User: caiosba
Functions: sudo
Tags: Network delay tc
7

Replace 500ms by the desired delay.

To remove it: sudo tc qdisc del dev lo root netem delay 500ms

delay until 16 && import_db.sh
2012-03-01 12:38:32
User: oernii2
1

the "delay" utility is an invaluable tool for me. with gnu-screen it allows you to schedule something and have it run and output to the current terminal, unlike "at".

You can also use it like "sleep" with seconds and also with date:

delay until 13:33 friday && echo test

get it from: http://onegeek.org/~tom/software/delay/current/delay.c

(author: Tom Rothamel)

echo 'some command' | batch
2010-07-14 03:08:31
User: kniht
Functions: echo
8

If shell escaping of the command is problematic, you can write the command to a file first:

batch <somefile

Or read it:

read -re && echo "$REPLY" | batch

Or, if your shell supports it, you can eliminate echo:

read -re && batch <<<$REPLY

("man batch" lists 1.5 for me, but I don't know how widely it differs.)

( ( while [ 2000 -ge "$(free -m | awk '/buffers.cache:/ {print $4}')" ] || [ $(echo "$(uptime | awk '{print $10}' | sed -e 's/,$//' -e 's/,/./') >= $(grep -c ^processor /proc/cpuinfo)" | bc) -eq 1 ]; do sleep 10; done; my-command > output.txt ) & )
2010-07-13 09:12:11
User: michelsberg
Functions: echo sleep
4

[ 2000 -ge "$(free -m | awk '/buffers.cache:/ {print $4}')" ] returns true if less than 2000 MB of RAM are available, so adjust this number to your needs.

[ $(echo "$(uptime | awk '{print $10}' | sed -e 's/,$//' -e 's/,/./') >= $(grep -c ^processor /proc/cpuinfo)" | bc) -eq 1 ] returns true if the current machine load is at least equal to the number of CPUs.

If either of the tests returns true we wait 10 seconds and check again. If both tests return false, i.e. 2GB are available and machine load falls below number of CPUs, we start our command and save it's output in a text file.

The ( ( ... ) & ) construct lets the command run in background even if we log out. See http://www.commandlinefu.com/commands/view/3115/ .