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repeat a command every one second
Short method of "while x=0; do foo ; sleep 1 ; done"

Printable random characters
Reads psuedorandom bytes from /dev/urandom, filtering out non-printable ones. Other character classes can be used, such as [:alpha:], [:digit:] and [:alnum:]. To get a string of 10 lowercase letters: $ tr -dc '[:lower:]' < /dev/urandom | head -c 10

back up your commandlinefu contributed commands
Use `zless` to read the content of your *rss.gz file: $ zless commandlinefu-contribs-backup-2009-08-10-07.40.39.rss.gz

check the status of 'dd' in progress

colored prompt
It colors the machine name and current directory different colors for easy viewing.

Close a hanging ssh session
~ is the ssh control character. If you type it after a newline, you can example force close the ssh session. , ~, then . If you want more info, type ~? when you are connecting using ssh. Very useful to kill of any hanging ssh sessions when nothing else works.

quickly backup or copy a file with bash

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

See a full last history by expanding logrotated wtmp files
When your wtmp files are being logrotated, here's an easy way to unpack them all on the fly to see more than a week in the past. The rm is the primitive way to prevent symlink prediction attack.

Cancel all aptitude scheduled actions
Very handy if you have done a package selection mistake in aptitude. Note that it's better to do a Ctrl+U (undo) in aptitude if possible, because the keep-all will clear some package states (like the 'hold' state).


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