All commands (14,187)

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

finds the c files with lines containing 'mcs', in the folders under the current folder

create a .avi with many .jpg

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" }

Print unique ipaddresses as they come in from Apache Access Log File
Prints the unique IP Addresses as they arrive from an Apache `access.log` file. The '-W interactive' tells awk to start writing to stdout immediately and not buffer the output. This command builds on the uniq lines without sorting command (http://www.commandlinefu.com/commands/view/4389/remove-duplicate-entries-in-a-file-without-sorting.)

Script executes itself on another host with one ssh command
Now put more interesting stuff on the script in replacement of hostname, even entire functions, etc, and stuff. hosta> cat myScript.sh #!/bin/sh [ $1 == "client" ] && hostname || cat $0 | ssh $1 /bin/sh -s client hosta> myScript.sh hostb hostb hosta>

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"

Randomly run command
Randomly decide whether to run a command, or fail. It's useful for testing purposes. . Usage: ran PERCENTAGE COMMAND [ARGS] Note: In this version the percentage is required. . This is like @sesom42 and @snipertyler's commands but in a USABLE form. . e.g. In your complicated shell script, put "ran 99" before a crucial component. Now, it will fail 1% of the time allowing you to test the failure code-path. $ ran 99 my_complex_program arg1 arg2

test moduli file generated for openssh
this command test the moduli file generated by the command ssh-keygen -G /tmp/moduli-2048.candidates -b 2048 . The test can be long depend of your cpu power , around 5 minutes to 30 minutes

Generate random valid mac addresses
Python Alternative

disable history for current shell session


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: