Commands by twjolson (5)

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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
http://www.mplayerhq.hu/DOCS/HTML/en/menc-feat-mpeg.html 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 http://www.codento.com/people/mtr/genscript/ "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: https://stackoverflow.com/a/9035939

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 8.8.8.8, 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.


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