Commands by tremby (1)

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Split and join with split and cat.
`split -b 1k file` splits files into 1k chunks. Rejoin them with `cat x* > file`.

Get Unique Hostnames from Apache Config Files
Get a list of all the unique hostnames from the apache configuration files. Handy to see what sites are running on a server. A slightly shorter version.

Cleanup Python bytecode files
This command will erase all bytecode versions of Python modules under the current directory.

Backup of a partition
Clone a partion with tar.

Get My Public IP Address

List contents of jar
useful to find the list of dependencies

reverse order of file

list files recursively by size

Limit memory usage per script/program
When I'm testing some scripts or programs, they end up using more memory than anticipated. In that case, computer nearly halts due to swap space usage, and sometimes I have to press Magic SysRq+REISUB to reboot. So, I was looking for a way to limit memory usage per script and found out that ulimit can limit memory. If you run it this way: $ $ ulimit -v 1000000 . $ $ scriptname Then the new memory limit will be valid for that shell. I think changing the limit within a subshell is much more flexible and it won't interfere with your current shell ulimit settings. note: -v 1000000 corresponds to approximately 1GB of RAM

mean color of an image
You can get the mean value for the colours in an image. Then you can determine, in general, how dark or bright is the image and run some other actions based on that. I'll recommend to readjust the brightness of the images using +sigmoidal-contrast option of imagemagick convert command.


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