Commands by bassu (2)

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See udev at work
See how your system works with pendrives/mice/monitors/whatever-you-can-plug-in. Use cases: see on which /dev/... your peripherals are, find out if a specific udev rule is being applied correctly.

Look up the definition of a word
A bash function might also be useful: $ dict() { curl dict://dict.org/d:$1; } Or if you want less verbose output: $ dict() { curl -s dict://dict.org/d:$1 | perl -ne 's/\r//; last if /^\.$/; print if /^151/../^250/'; }

Big (four-byte) $RANDOM
Sometimes, in a shell script, you need a random number bigger than the range of $RANDOM. This will print a random number made of four hex values extracted from /dev/urandom.

Identify long lines in a file
This command displays a list of lines that are longer than 72 characters. I use this command to identify those lines in my scripts and cut them short the way I like it.

Analyze awk fields
Breaks down and numbers each line and it's fields. This is really useful when you are going to parse something with awk but aren't sure exactly where to start.

Automatic ssh Session Logger
A wrapper around ssh to automatically provide logging and session handling. This function runs ssh, which runs screen, which runs script. . The logs and the screen session are stored on the server. This means you can leave a session running and re-attach to it later, or from another machine. . . Requirements: * Log sessions on a remote server * Transparent - nothing extra to type * No installation - nothing to copy to the server beforehand . Features: * Function wrapper delegating to ssh - so nothing to remember - uses .ssh/config as expected - passes your command line option to ssh * Self-contained: no scripts to install on the server * Uses screen(1), so is: - detachable - re-attachable - shareable * Records session using script(1) * Configurable log file location, which may contain variables or whitespace L="$HOME" # local variable L="\$HOME" # server variable L="some space" . Limitations: * Log dir/file may not contain '~' (which would require eval on the server) . . The sessions are named by the local user connecting to the server. Therefore if you detach and re-run the same command you will reconnect to your original session. If you want to connect/share another's session simply run: $ USER=bob ssh root@server . The command above is stripped down to an absolute minimum. A fully expanded and annotated version is available as a Gist (git pastebin): https://gist.github.com/flatcap/3c42326abeb1197ee714 . If you want to add timing info to script, change the command to: $ ssh(){ L="\$HOME/logs/$(date +%F_%H:%M)-$USER";/usr/bin/ssh -t "$@" "mkdir -p \"${L%/*}\";screen -xRRS $USER script --timing=\"$L-timing\" -f \"$L\"";}

Stream (almost) any music track in mplayer
Just give it an artist and/or song at the end of the command as shown.

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

Wait for file to stop changing
This loop will finish if a file hasn't changed in the last 10 seconds. . It checks the file's modification timestamp against the clock. If 10 seconds have elapsed without any change to the file, then the loop ends. . This script will give a false positive if there's a 10 second delay between updates, e.g. due to network congestion . How does it work? 'date +%s' gives the current time in seconds 'stat -c %Y' gives the file's last modification time in seconds '$(( ))' is bash's way of doing maths '[ X -lt 10 ]' tests the result is Less Than 10 otherwise sleep for 1 second and repeat . Note: Clever as this script is, inotify is smarter.

Get Hardware UUID in Mac OS X
Formats the output from `ioreg` into XML, then parses the XML with `xmllint`'s xpath feature.


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