Commands by liam (1)

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delay: a simple scheduler
the "delay" utility is an invaluable tool for me. with gnu-screen it allows you to schedule something and have it run and output to the current terminal, unlike "at". You can also use it like "sleep" with seconds and also with date: delay until 13:33 friday && echo test get it from: http://onegeek.org/~tom/software/delay/current/delay.c (author: Tom Rothamel)

Convert seconds to [DD:][HH:]MM:SS
Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

Check syntax of remote ruby file

Limit bandwidth usage by apt-get
Limits the usage of bandwidth by apt-get, in the example the command will use 30Kb/s ;) It should work for most apt-get actions (install, update, upgrade, dist-upgrade, etc.)

Normalize volume in your mp3 library
This normalizes volume in your mp3 library, but uses mp3gain's "album" mode. This applies a gain change to all files from each directory (which are presumed to be from the same album) - so their volume relative to one another is changed, while the average album volume is normalized. This is done because if one track from an album is quieter or louder than the others, it was probably meant to be that way.

small CPU benchmark with PI, bc and time.
$ # 4 cores with 2500 pi digits $ CPUBENCH 4 2500 $. $ every core will use 100% cpu and you can see how fast they calculate it. $ if you do 50000 digitits and more it can take hours or days

Customize time format of 'ls -l'
the --time-style argument to 'ls' takes several possible modifiers: full-iso, long-iso, iso, locale, +FORMAT. The +FORMAT modifier uses the same syntax as date +FORMAT. --time-style=+"%Y-%m-%d %H:%M:%S" strikes a happy medium between accuracy and verbosity: $ ls -lart --time-style=long-iso doesn't show time down to the nearest second, $ ls -lart --time-style=full-iso displays time to 10E-9 second resolution, but with no significant digits past the full seconds, also showing the timezone: $ -rw-r--r-- 1 bchittenden bchittenden 0 2011-02-10 12:07:55.000000000 -0500 bar

Piping Microphone Audio Over Netcat
Send microphone audio to another computer using netcat and arecord. Connect to the stream using "nc [other ip] 3333|aplay" You can set up two-way communication by piping audio the reverse direction on another port: Machine #1: $arecord -D hw:0,0 -f S16_LE -c2|nc -l 3333 &;nc -l 3334|aplay Machine #2: $$ip=[machine1_ip];arecord -D hw:0,0 -f S16_LE -c2|nc $ip 3334 &;nc $ip 3333|aplay

remove execute bit only from files. recursively

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.


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