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

Optimal way of deleting huge numbers of files
This command works by rsyncing the target directory (containing the files you want to delete) with an empty directory. The '--delete' switch instructs rsync to remove files that are not present in the source directory. Since there are no files there, all the files will be deleted. I'm not clear on why it's faster than 'find -delete', but it is. Benchmarks here: https://web.archive.org/web/20130929001850/http://linuxnote.net/jianingy/en/linux/a-fast-way-to-remove-huge-number-of-files.html

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"

The Chromium OS rootfs is mounted read-only. In developer mode you can disable the rootfs verification, enabling it to be modified.

Get all files of particular type (say, PDF) listed on some wegpage (say, example.com)
This example command fetches 'example.com' webpage and then fetches+saves all PDF files listed (linked to) on that webpage. [*Note: of course there are no PDFs on example.com. This is just an example]

Stream system sounds over rtmp
sox (SOund eXchange) can capture the system audio be it a browser playing youtube or from hardware mic and can pipe it to ffmpeg which encodes it into flv and send it over rtmp. Tested using Red5 rtmp server.

gets all files committed to svn by a particular user since a particular date
just change the date following the -r flag, and/or the user name in the user== conditional statement, and substitute yms_web with the name of your module

Figure out your work output for the day
Figures out what has changed in the last 12 hours. Change the author to yourself, change the time since to whatever you want.

Query well known ports list
Uses the file located in /etc/services

Display the standard deviation of a column of numbers with awk


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