Commands by kot9pko (1)

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

Setup an ssh tunnel
Uses ssh as tunnel tunnel for an other connection. -f runs ssh in the background -N tell that there is no command to run -L deals with the forwarding aspect where the first number is the local port number, the second is parameter is the name of the server to forward to and the third parameter is the port number on that server. The last part of the command is the usual ssh form consisting of the user name and remote server name

determine if tcp port is open
Requires netcat.

Generate a random password 30 characters long
This command is similar to the alternate, except with head(1), you can pick as many passwords as you wish to generate by changing the number of lines you wish to preview.

List mp3 files with less than 320 kbps bitrate.

Matrix Style

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" }

Format date/time string for a different day
The "date' command has options to easily format the date, day, month, time, etc. But what if you want a relative date or time. Like, I wanted yesterday's date in a particular format. You may want the exact date of "2 months ago" or "-3 days" nicely formatted. For that, you can use this command. The --date option takes fuzzy parameters like the ones mentioned in the previous sentence.

convert a web page into a pdf
This uses the "command-line print" plugin for Firefox (http://torisugari.googlepages.com/commandlineprint2). This same plugin can also produce PNGs. On *nix, the file must exist; therefore the touch bit in front. Also, firefox seems to ignore saved user preferences when "printing" this way (margins, header, footer, etc.), so I had to tweak my ~/.mozilla/firefox/xxxxxxxx.default/prefs.js file by hand. Yup, that's *prefs.js* not user.js - apparently, firefox ignores my user.js file too...

Install a Firefox add-on/theme to all users
To install a theme use: $ sudo firefox -install-global-theme /path/to/theme You can get the .xpi or .jar file from the versions history on the add-on/theme page. NOTE: may not work in your system (Debian-based is an example).

Check if you need to run LaTeX to update the TOC
To check if the table-of-content in a LaTeX document is up-to-date, copy it to a backup before running LaTeX and compare the new .toc to the backup. If they are identical, it is updated. If not, you need to run LaTeX again.


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: