Commands by B4ckBOne (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

copy audio file from playlist to a floder
copy some file from xx.m3u to target folder

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" }

find out how many days since given date
You can also do this for seconds, minutes, hours, etc... Can't use dates before the epoch, though.

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"

Bitcoin Brainwallet Private Key Calculator
A bitcoin "brainwallet" is a secret passphrase you carry in the "wallet" of your brain. The Bitcoin Brainwallet Private Key Calculator calculates the standard base58 encoded bitcoin private key from your "brainwallet" passphrase. The private key is the most important bitcoin number. All other numbers can be derived from it. This command uses 3 other functions - all 3 are defined on my user page: 1) brainwallet_exponent() - search for Bitcoin Brainwallet Exponent Calculator 2) brainwallet_checksum() - search for Bitcoin Brainwallet Exponent Calculator 3) b58encode() - search for Bitcoin Brainwallet Base58 Encoder Do make sure you use really strong, unpredictable passphrases (30+ characters)! http:brainwallet.org can be used to check the accuracy of this calculator.

Notify me when users log in
Notifyme is a program that listen in background for users login, and report on login and logout. Users can be specified from a list or in a ~/notify.rc file. -C options force to display messages on the center of the screen.See man notifyme for more details. Part of notifyme package, tested on Debian.

Send test prints to networked printer.
This will send a test print job to a networked printer.

Start screen with name and run command
Runs an instance of screen with name of "name_me" and command of "echo "hi"" To reconnect to screen instance later use: screen -r name_me

Colorized grep in less
Get your colorized grep output in less(1). This involves two things: forcing grep to output colors even though it's not going to a terminal and telling less to handle those properly.

alt + 1 .
alt + number + dot will insert last command argument at $number place, alt + 0 + . will print last command name. For example $ ls /tmp /var $ ls /usr /home alt + 1 + . will result in '/usr' , if you press alt + . again, it will result in '/tmp' alt + 0 + . -> 'ls'


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: