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Send an email from the terminal when job finishes
Might as well include the status code it exited with so you know right away if it failed or not.

Convert your favorite image in xpm for using in grub
* size must be 640?480 pixels * only has 14 colors * save it in XPM format Edit /boot/grub/menu.lst and add splashimage=(hd0,0)/boot/grub/grubimg.xpm make sure for your path name and hard disk

Quick HTML image gallery from folder contents
Setting: You have a lot of jpg files in a directory. Maybe your public_html folder which is readable on the net because of Apache's mod_userdir. All those files from the current folder will be dropped into a file called gallery.html as image tags that can be viewed within a web browser locally or or over the Internet. Original: $find . -iname "*.jpg" -exec echo "" >> gallery.html \;

List all commands present on system

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"

Function that outputs dots every second until command completes
Very useful in shell scripts because you can run a task nicely in the background using job-control and output progress until it completes. Here's an example of how I use it in backup scripts to run gpg in the background to encrypt an archive file (which I create in this same way). $! is the process ID of the last run command, which is saved here as the variable PI, then sleeper is called with the process id of the gpg task (PI), and sleeper is also specified to output : instead of the default . every 3 seconds instead of the default 1. So a shorter version would be sleeper $!; The wait is also used here, though it may not be needed on your system. $ echo ">>> ENCRYPTING SQL BACKUP" $ gpg --output archive.tgz.asc --encrypt archive.tgz 1>/dev/null & $ PI=$!; sleeper $PI ":" 3; wait $PI && rm archive.tgz &>/dev/null Previously to get around the $! not always being available, I would instead check for the existance of the process ID by checking if the directory /proc/$PID existed, but not everyone uses proc anymore. That version is currently the one at http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html but I plan on upgrading to this new version soon.

Find usb device
I often use it to find recently added ou removed device, or using find in /dev, or anything similar. Just run the command, plug the device, and wait to see him and only him

Multi-thread any command
For instance: $ find . -type f -name '*.wav' -print0 |xargs -0 -P 3 -n 1 flac -V8 will encode all .wav files into FLAC in parallel. Explanation of xargs flags: -P [max-procs]: Max number of invocations to run at once. Set to 0 to run all at once [potentially dangerous re: excessive RAM usage]. -n [max-args]: Max number of arguments from the list to send to each invocation. -0: Stdin is a null-terminated list. I use xargs to build parallel-processing frameworks into my scripts like the one here: http://pastebin.com/1GvcifYa

Delete empty directories
Recursively delete empty directories. Use with care.

Find usb device in realtime
Using this command you can track a moment when usb device was attached.


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