Commands by Weboide (3)

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

Set laptop display brightness
Run as root. Path may vary depending on laptop model and video card (this was tested on an Acer laptop with ATI HD3200 video). $ cat /proc/acpi/video/VGA/LCD/brightness to discover the possible values for your display.

Locking and unlocking files and mailboxes
Programs for locking and unlocking files and mailboxes.This package includes several programs to safely lock and unlock files and mailboxes from the command line. These include: lockfile-create lockfile-remove lockfile-touchlock mail-lock mail-unlock mail-touchlock These programs use liblockfile to perform the file locking and unlocking, so they are guaranteed compatible with Debian's file locking policies.

Test how well a web server handles concurrent connections and big load.
This command will execute 1000 requests to the http URL http://127.0.0.1:8000 handlink 100 concurent connections at a time. Then it will display statistics about the time that have been taken.

Convert seconds to [DD:][HH:]MM:SS
Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

Use default value if unassigned
Will use variable value (for variable $my_dir, in this case), an assign a default value if there is none.

Continue a current job in the background

Then end of the UNIX epoch
http://en.wikipedia.org/wiki/Year_2038_problem Some other notable dates that have passed: $ date -d@1234567890 $ date -d@1000000000

display an embeded help message from bash script header
With this one liner you can easily output a standard help message using the following convention: Usage: is the start marker Stop at the last #

32 bits or 64 bits?

purge installed but unused linux headers, image, or modules
will purge: only installed apps: /^ii/!d avoiding current kernel stuff: /'"$(uname -r | sed "s/\(.*\)-\([^0-9]\+\)/\1/")"'/d using app names: s/^[^ ]* [^ ]* \([^ ]*\).*/\1/ avoiding stuff without a version number: /[0-9]/!d


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: