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

Check if a machine is online
PING parameters c 1 limits to 1 pinging attempt q makes the command quiet (or silent mode) /dev/null 2>&1 is to remove the display && echo ONLINE is executed if previous command is successful (return value 0) || echo OFFLINE is executed otherwise (return value of 1 if unreachable or 2 if you're offline yourself). I personally use this command as an alias with a predefined machine name but there are at least 2 improvements that may be done. Asking for the machine name or IP Escaping the output so that it displays ONLINE in green and OFFLINE in red (for instance).

need ascii art pictures for you readme text ?
Require boxes and / or cowsay packages. After input boxes -d dog , type your text and then press ctrl + d . Same goes for cowsay .

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" }

Rename files in batch

Launch firefox on a remote linux server
Actually 'firefox' is a script that then launches the 'firefox-bin' executable. You need to specify the 'no-remote' option in order to launch remote firefox instead of your local one (this drove me crazy time ago)

sort ugly text
Often, when sorting you want the sort to ignore extraneous characters. The b, d, and f tell sort to ignore leading blanks, use 'dictionary order' (ignore punctuation), and ignore (fold) case. Add a "u" if you only want one copy of duplicate lines. This is a great command to use within vim to sort lines of text, using !}sort -bdf

Matrix Style
I like the fact the Patola's version uses only ones and zeros, but I also like the sparse output of the other versions. This one combines both of those features and eliminates some unnecessary cruft. You can vary the sparseness by changing "$(($RANDOM % 5))" to another number. The number in this term "$(($RANDOM % 4))" controls how frequently the numbers are output bold.

One-liner to generate Self-Signed SSL Certificate+Key without any annoying prompts or CSRs
Handy if you want to quickly generate a self-signed certificate. Also can be used in your automated scripts for generating quick-use certificates.

Backup a file with a date-time stamp
Appends the input file with the date format YYYY-MM-DD.bak. Also runs silently if you remove the -v on the cp at the end of the function.

Watching Command
If you need to keep an eye on a command whose output is changing, use the watch command. For example, to keep an eye on your load average


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: