Commands tagged focus (2)

What's this?

commandlinefu.com 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


Check These Out

Write comments to your history.
A null operation with the name 'comment', allowing comments to be written to HISTFILE. Prepending '#' to a command will *not* write the command to the history file, although it will be available for the current session, thus '#' is not useful for keeping track of comments past the current session.

Find usb device in realtime
Using this command you can track a moment when usb device was attached.

Look up the definition of a word
A bash function might also be useful: $ dict() { curl dict://dict.org/d:$1; } Or if you want less verbose output: $ dict() { curl -s dict://dict.org/d:$1 | perl -ne 's/\r//; last if /^\.$/; print if /^151/../^250/'; }

Calculate days on which Friday the 13th occurs (inspired from the work of the user justsomeguy)
Friday is the 5th day of the week, monday is the 1st. Output may be affected by locale.

Define a quick calculator function
POSIX compliant arithmetic evaluation. = 10*2+3

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Preserve user variables when running commands with sudo.
In this case the current user has proxy variable set which allows access to the rpm on the internet but needs root privs to install it. Running sudo -E preserves the current user proxy var and allows the rpm install to be executed with sudo.

python smtp server
This command will start a simple SMTP server listening on port 1025 of localhost. This server simply prints to standard output all email headers and the email body.

HourGlass
Displays an animated hourglass for x amount of seconds

Remount an already-mounted filesystem without unmounting it
Necessary for fsck for example. The remount functionality follows the standard way how the mount command works with options from fstab. It means the mount command doesn't read fstab (or mtab) only when a device and dir are fully specified. After this call all old mount options are replaced and arbitrary stuff from fstab is ignored, except the loop= option which is internally generated and maintained by the mount command. It does not change device or mount point.


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: