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find the difference between two nodes

Release memory used by the Linux kernel on caches
=1 --> to free pagecache =2 --> to free dentries and inodes =3 --> to free pagecache, dentries and inodes

list ips with high number of connections

Add a line from 1 file after every line of another (shuffle files together)
After every line in targetfile (empty lines included) insert in a line from addfile. "Save" results to savefile. Addfile should be longer than targetfile since this doesn't loop back to the top of addfile. /^/R addfile -- says for every line that matches "has a start of line" output a line from the file addfile. > savefile (optional) -- redirect output to savefile file.

Replace duplicate files by hardlinks

Detect illegal access to kernel space, potentially useful for Meltdown detection
Based on capsule8 agent examples, not rigorously tested

Rolling upgrades via aptitude
This has been my "sysupgrade" alias since ca. 2006, first used on Debian Sid, then Sabayon, and it still does its duty on Mint nowadays without breaking stuff.

Quick way to sum every numbers in a file written line by line
If you have a file full of numbers written line by line, you can sum every line to get the total. With a file like this: 3443535 9878977 67554 987798 232324 you will got: 14610188

Calculate pi to an arbitrary number of decimal places

Detect encoding of a text file
This command gives you the charset of a text file, which would be handy if you have no idea of the encoding.


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