Commands by twjolson (5)

What's this? 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

Create md5sum of a directory

Identify differences between directories (possibly on different servers)
This can be much faster than downloading one or both trees to a common servers and comparing the files there. After, only those files could be copied down for deeper comparison if needed.

List the Sizes of Folders and Directories
I wanted an easy way to list out the sizes of directories and all of the contents of those directories recursively.

Encoding from AVI to MPEG format MEncoder can create MPEG (MPEG-PS) format output files. Usually, when you are using MPEG-1 or MPEG-2 video, it is because you are encoding for a constrained format such as SVCD, VCD, or DVD. To change MEncoder's output file format, use the -of mpeg option. Creating an MPEG-1 file suitable to be played on systems with minimal multimedia support, such as default Windows installs: $ mencoder input.avi -of mpeg -mpegopts format=mpeg1:tsaf:muxrate=2000 \ -o output.mpg -oac lavc -lavcopts acodec=mp2:abitrate=224 -ovc lavc \ -lavcopts vcodec=mpeg1video:vbitrate=1152:keyint=15:mbd=2:aspect=4/3

Convert the output of one or more (log, source code ...) files into html,
Requires the "enscript" package. [email protected]:~# sudo apt-get install enscript Or "use your head"

Rename file to same name plus datestamp of last modification.
Note that the -i will not help in a script. Proper error checking is required.

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"

get rid of lines with non ascii characters
found here:

Grab IP address on machine with multiple interfaces
Instead of hard-coding in a check to scrape info from ifconfig based on a specific interface, do it in a more portable way. This works really well if you switch between wired, wireless, bluetooth or even VPN connections. You can get your current IP in a script (since it'll be something like tun0 instead of eth0 or wlan1). This uses a well known public ip address, but it doesn't actually connect to it, it just shows you the route it would take.

Count TCP States From Netstat
Counts TCP states from Netstat and displays in an ordered list.

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.


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: