Commands using uniq (255)

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

Restore user,group and mod of an entire website
I often use it at my work, on an ovh server with root ssh access and often have to change mod after having finished an operation. This command, replace the user, group and mod by the one required by apache to work.

list block devices
Shows all block devices in a tree with descruptions of what they are.

Validating a file with checksum

launch bash without using any letters
ry4an@four:~$ echo $SHLVL 1 ry4an@four:~$ ${0/-/} ry4an@four:~$ echo $SHLVL 2

Read and write to TCP or UDP sockets with common bash tools
Ever needed to test firewalls but didn't have netcat, telnet or even FTP? Enter /dev/tcp, your new best friend. /dev/tcp/(hostname)/(port) is a bash builtin that bash can use to open connections to TCP and UDP ports. This one-liner opens a connection on a port to a server and lets you read and write to it from the terminal. How it works: First, exec sets up a redirect for /dev/tcp/$server/$port to file descriptor 5. Then, as per some excellent feedback from @flatcap, we launch a redirect from file descriptor 5 to STDOUT and send that to the background (which is what causes the PID to be printed when the commands are run), and then redirect STDIN to file descriptor 5 with the second cat. Finally, when the second cat dies (the connection is closed), we clean up the file descriptor with 'exec 5>&-'. It can be used to test FTP, HTTP, NTP, or can connect to netcat listening on a port (makes for a simple chat client!) Replace /tcp/ with /udp/ to use UDP instead.

Create a mirror of a local folder, on a remote server
Create a exact mirror of the local folder "/root/files", on remote server 'remote_server' using SSH command (listening on port 22) (all files & folders on destination server/folder will be deleted)

Getting a domain from url, ex: very nice to get url from squid access.log

replace strings in file names
Uses vi style search / replace in bash to rename files. Works with regex's too (I use the following a script to fixup / shorten file names): # Remove complete parenthetical/bracket/brace phrases rename 's/\(.*\)//g' * rename 's/\[.*\]//g' * rename 's/\{.*\}//g' *

Pronounce an English word using Merriam-Webster.com
Looks up a word on merriam-webster.com, does a screen scrape for the FIRST audio pronunciation and plays it. USAGE: Put this one-liner into a shell script (e.g., ~/bin/pronounce) and run it from the command line giving it the word to say: $ pronounce lek If the word isn't found in merriam-webster, no audio is played and the script returns an error value. However, M-W is a fairly complete dictionary (better than howjsay.com which won't let you hear how to pronounce naughty words). ASSUMPTIONS: GNU's sed (which supports -r for extended regular expressions) and Linux's aplay. Aplay can be replaced by any program that can play .WAV files from stdin. KNOWN BUGS: only the FIRST pronunciation is played, which is problematic if you wanted a particular form (plural, adjectival, etc) of the word. For example, if you run this: $ pronounce onomatopoetic you'll hear a voice saying "onomatopoeia". Playing the correct form of the word is possible, but doing so might make the screen scraper even more fragile than it already is. (The slightest change to the format of m-w.com could break it).

Read funny developer comments in the Linux source tree
These are way better than fortune(6).


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: