A shorter version Show Sample Output

Watch the temperatures of your CPU cores in real time at the command line. Press CONTROL+C to end. GORY DETAILS: Your computer needs to support sensors (many laptops, for example, do not). You'll need to install the lm-sensors package if it isn't already installed. And it helps to run the `sensors-detect` command to set up your sensor kernel modules first. At the very end of the sensors-detect interactive shell prompt, answer YES to add the new lines to the list of kernel modules loaded at boot. Show Sample Output

Take a screenshot every 2 seconds and save it as a png file

Use acpi and notify-send to report current temperature every five minutes. Works best in a shell script run at startup. acpi is called for temperature and fed to notify-send for a tooltip. After waiting five minutes, it will start over.

Use the command to create a script and bind it to a key using keyboard shortcut. eg: Script locks the screen in a loop until the command is executed again.At first it

Checks your gmail account every 30 seconds and display the number of new messages in the top right corner of the terminal. A kind of CLI "Gmail notifier" if you will. :-) This is a mashup of http://www.commandlinefu.com/commands/view/7916/put-a-console-clock-in-top-right-corner and http://www.commandlinefu.com/commands/view/3386/check-your-unread-gmail-from-the-command-line

When aliens invade Earth, be first to warn your neighbours by placing your computer screen at a window and executing this potentially Earth-saving command. Ctrl C when aliens are defeated.

In this case it runs the command 'curl localhost:3000/site/sha' waiting the amount of time in sleep, ie: 1 second between runs, appending each run to the console. This works well for any command where the output is less than your line width This is unlike watch, because watch always clears the display. Show Sample Output

I'm flat-out surprised that minecraft directory services require servers install multiple modifications to their server code, when the directories could fetch this information on their own. Show Sample Output

The previously-posted one-liner didn't work for me for whatever reason, so I ended up doing this instead.

Some IO intensive process make the system unresponsive. This function periodically starts/stops a process, which hopefully releases some resources for other activities. This function is useful when ionice is not available Show Sample Output

Same effect, only shell commands. Show Sample Output

http://www.joachim-breitner.de/projects#screen-message now also supports reading stdin continuously to update what it shows, different ?slides? separated by a form feed character. Here, we feed the current time into it each second to create a large clock.

Case insensitive. Also you can pull in the songs from a blacklist, one per line - while :; do (mpc current | grep -i -f blacklist.txt && mpc next); sleep 5; done

Execute a process or list of commands in the given interval and output the difference in output. Show Sample Output

The closer to zero the better.Credit to TheSeb on macrumors: http://forums.macrumors.com/showthread.php?t=1289884 Show Sample Output

While a dd is running in one terminal, open another and enter the while loop. The sample output will be displayed in the window running the dd and the while loop will exit when the dd is complete. It's possible that a "sudo" will need to be inserted before "pkill", depending on your setup, for example: while pgrep ^dd; do sudo pkill -INFO dd; sleep 10; done Show Sample Output

A nice way to interrupt a sleep with a signal. Show Sample Output

Lots of scripts show you how to use socat to send an email to an SMTP server; this command actually emulates an SMTP server! It assumes the client is only sending to one recipient, and it's not at all smart, but it'll capture the email into a log file and the client will stop retrying. I used this to diagnose what emails were being sent by cron and subsequently discarded, but you can use it for all sorts of things. Show Sample Output

This checks the system load every second and if it's over a certain threshold (.8 in this example), it spits out the date, system loads and top 4 processes sorted by CPU. Additionally, the \a in the first echo creates an audible bell.

Online games have pretty good lag compensation nowadays, Sometimes though, you really want to get some warning about your latency, e.g. while playing Diablo III in Hardcore mode, so you know when to carefully quit the game b/c your flatmate started downloading all his torrents at once. This is done on Darwin. On Linux/*nix you would need to find another suitable command instead of `say` to spell out your latency. And I used fping because it's a little bit easier to get the latency value needed. Something similar with our regular ping command could look like this: while :; do a=$(ping -c1 google.com | grep -o 'time.*' | cut -d\= -f2 | cut -d\ -f1 | cut -b1-4); [[ $a > 40 ]] && say "ping is $a"; sleep 3; done