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Use /dev/full to test language I/O-failsafety
The Linux /dev/full file simulates a "disk full" condition, and can be used to verify how a program handles this situation. In particular, several programming language implementations do not print error diagnostics (nor exit with error status) when I/O errors like this occur, unless the programmer has taken additional steps. That is, simple code in these languages does not fail safely. In addition to Perl, C, C++, Tcl, and Lua (for some functions) also appear not to fail safely.

Search for packages, ranked by popularity
This will take the packages matching a given `apt-cache search` query (a collection of AND'd words or regexps) and tell you how popular they are. This is particularly nice for those times you have to figure out which solution to use for e.g. a PDF reader or a VNC client. Substitute "ubuntu.com" for "debian.org" if you want this to use Ubuntu's data instead. Everything else will work perfectly.

Disassemble all ACPI tables on your system
The fact that Linux exposes the ACPI tables to the user via sysfs makes them a gold mine of valuable hardware information for low-level developers. Looping through each of them and disassembling them all makes them even more valuable.

Get duration of an audio file in seconds.
This is an alternative to #9131. ffmpeg didn't work on my .au files, though it did on the .wav ones. Also useful if you don't have ffmpeg but do have sox. Handily, sox already reports in seconds (decimal).

easily find megabyte eating files or directories

Clean up the garbage an accidental unzipping makes
List out all the names from the zip file and pass it to xargs utility to delete each one of them

Set laptop display brightness
Run as root. Path may vary depending on laptop model and video card (this was tested on an Acer laptop with ATI HD3200 video). $ cat /proc/acpi/video/VGA/LCD/brightness to discover the possible values for your display.

locate a filename, make sure it exists and display it with full details
use the locate command to find files on the system and verify they exist (-e) then display each one in full details.

Randomize lines in a file
This appends a random number as a first filed of all lines in SOMEFILE then sorts by the first column and finally cuts of the random numbers.

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


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