Commands by lowbatteries (1)

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clean up memory of unnecessary things (Kernerl 2.6.16 or newer)
run sync first to flush useful things out to disk!!! To free pagecache: echo 1 > /proc/sys/vm/drop_caches To free dentries and inodes: echo 2 > /proc/sys/vm/drop_caches To free pagecache, dentries and inodes: echo 3 > /proc/sys/vm/drop_caches

find out how many days since given date
Exactly the same number of characters, exactly the same results, but with bc

Pick a random line from a file

Find Out My Linux Distribution Name and Version
Another way of do it in debian like distros, don't know if works for others

reverse order of file

list block devices
Shows all block devices in a tree with descruptions of what they are.

Use top to monitor only all processes with the same name fragment 'foo'
Like command 10870, but no need for sed

Simulate typing

Mac OS X: Change Color of the ls Command
I use terminal with black background on the Mac. Unfortunately, the default ls color for the directory is blue, which is very hard to see. By including the line above in my ~/.bash_profile file, I changed the directory's color to cyan, which is easer to see. For more information on the syntax of the LSCOLORS shell variable: $ man ls I tested this command on Mac OS X Leopard

Summarize the number of open TCP connections by state
Useful for checking the number and state of TCP connections.

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