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

Stores the certificate expiration date on the variable A
Stores the certificate expiration date on the variable A

find established tcp connections without using netstat!!
Fast and easy way to find all established tcp connections without using the netstat command.

Check your bash shell for vulnerability to the ShellShock exploit
If this command prints 'x' then your shell is vulnerable. Null output confirms that you are protected. Further reading: http://allanmcrae.com/2014/09/shellshock-and-arch-linux/

Convert CSV to JSON
Replace 'csv_file.csv' with your filename.

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"

Locate config files of the program
Locate config files of the program. May not be used for interactive programs like vim.

Generate a binary file with all ones (0xff) in it
This is similar to how you would generate a file with all zeros $ dd if=/dev/zero of=allzeros bs=1024 count=2k

5 Which Aliases
5 helpful aliases for using the which utility, specifically for the GNU which (2.16 tested) that is included in coreutils. Which is run first for a command. Same as type builtin minus verbosity $ alias which='{ command alias; command declare -f; } | command which --read-functions --read-alias' Which (a)lias $ alias whicha='command alias | command which --read-alias' Which (f)unction $ alias whichf='command declare -f | command which --read-functions' Which e(x)ecutable file in PATH $ alias whichx='command which' Which (all) alias, function, builtin, and files in PATH $ alias whichall='{ command alias; command declare -f; } | command which --read-functions --read-alias -a' # From my .bash_profile http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html

Optimal way of deleting huge numbers of files
Optimal way of deleting huge numbers of files Using -delete is faster than: $ find /path/to/dir -type f -print0 | xargs -0 rm $ find /path/to/dir -type f -exec rm {} + $ find /path/to/dir -type f -exec rm \-f {} \;

Get all mac address
I prefer the ip command to ifconfig as ifconfig is supposedly going to be deprecated. Certain IP address aliases can only be seen with the ip command (such as the ones applied by RHCS).


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: