Commands by ptotaram (1)

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.

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Find Duplicate Files (based on size first, then MD5 hash)
This dup finder saves time by comparing size first, then md5sum, it doesn't delete anything, just lists them.

Short one line while loop that outputs parameterized content from one file to another
There is a common command for outputting a field or list of fields from each line in a file. Why wouldn't you just use cut?

lotto generator

A "Web 2.0" domain name generator and look for register availability
You would need pwgen installed first, on ubuntu you can get it by apt-get $ sudo apt-get install pwgen

Selecting a random file/folder of a folder
Also looks in subfolders

Extract audio track from a video file using mencoder
Extracts an MP3 encoded audio stream from an input video file.

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"

Find usb device in realtime
Using this command you can track a moment when usb device was attached.

delay execution of a command that needs lots of memory and CPU time until the resources are available
[ 2000 -ge "$(free -m | awk '/buffers.cache:/ {print $4}')" ] returns true if less than 2000 MB of RAM are available, so adjust this number to your needs. [ $(echo "$(uptime | awk '{print $10}' | sed -e 's/,$//' -e 's/,/./') >= $(grep -c ^processor /proc/cpuinfo)" | bc) -eq 1 ] returns true if the current machine load is at least equal to the number of CPUs. If either of the tests returns true we wait 10 seconds and check again. If both tests return false, i.e. 2GB are available and machine load falls below number of CPUs, we start our command and save it's output in a text file. The ( ( ... ) & ) construct lets the command run in background even if we log out. See .

Delete empty directories with zsh
This command uses the recursive glob and glob qualifiers from zsh. This will remove all the empty directories from the current directory down. The **/* recurses down through all the files and directories The glob qualifiers are added into the parenthesis. The / means only directories. The F means 'full' directories, and the ^ reverses that to mean non-full directories. For more info on these qualifiers see the zsh docs:

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