Commands by yaMatt (1)

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

What is my public IP address
Clean output, if used in scripts: $ GET checkip.dyndns.org|grep -o '[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}' or $ GET icanhazip.com

dmesg with colored human-readable dates
Use sed to color the output of a human-readable dmesg output

Create a tar archive using xz compression
compress directory archive with xz compression, if tar doesn't have the -J option (OSX tar doesn't have -J)

Create a bunch of dummy files for testing
Sometimes I need to create a directory of files to operate on to test out some commandlinefu I am cooking up. The main thing is the range ({1..N}) expansion.

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" }

Multi line grep using sed and specifying open/close tags
Working with log files that contains variable length messages wrapped between open and close tags it may be useful to filter the messages upon a keyword. This works fine with GNU sed version 4.2 or higher, so pay attention to some unix distros (solaris, hp-ux, etc.). Linux should be ok.

Create a continuous digital clock in Linux terminal
Source: http://www.my-guides.net/en/guides/linux/364-how-to-create-a-continuous-digital-clock-in-linux-terminal

Disable beep sound from your computer
This command will disable the beep sound from the PC speaker.

reverse order of file
awk reverse order of lines (emulates "tac")

Speed up or slow down video (and audio)
Usage: videospeed video_filename speedchange newfilename videospeed foo.mp4 0.5 foo_slow.mp4 Range of 0.5 (50%) - 2.0 (200%) is valid.


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: