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Find processes stuck in dreaded "D" state aka IO Wait
Lots of fun to run on nfs clients when the server or network connection is having issues

Show all mergeinfo for a svn subtree

Get AWS temporary credentials ready to export based on a MFA virtual appliance
You might want to secure your AWS operations requiring to use a MFA token. But then to use API or tools, you need to pass credentials generated with a MFA token. This commands asks you for the MFA code and retrieves these credentials using AWS Cli. To print the exports, you can use: `awk '{ print "export AWS_ACCESS_KEY_ID=\"" $1 "\"\n" "export AWS_SECRET_ACCESS_KEY=\"" $2 "\"\n" "export AWS_SESSION_TOKEN=\"" $3 "\"" }'` You must adapt the command line to include: * $MFA_IDis ARN of the virtual MFA or serial number of the physical one * TTL for the credentials

Python version 3: Serve current directory tree at http://$HOSTNAME:8000/
In Python version 3, the module was merged into http.server. Gentlemen, change your aliases.

clean up memory of unnecessary things (Kernerl 2.6.16 or newer)
run sync first to flush useful things out to disk!!! To free pagecache: echo 1 > /proc/sys/vm/drop_caches To free dentries and inodes: echo 2 > /proc/sys/vm/drop_caches To free pagecache, dentries and inodes: echo 3 > /proc/sys/vm/drop_caches

Run a command as root, with a delay
$ sleep 1h ; sudo command or $ sudo sleep 1h ; sudo command won't work, because by the time the delay is up, sudo will want your password again.

Throttling Bandwidth On A Mac
sudo ipfw pipe 1 config bw 50KByte/s Set the bandwidth (bw) limit to any number you want. For example you could have a 15kb pipe for X application and then a 100kb pipe for another application and attach things to those pipes. If a port isn’t attached to a pipe, it runs at full speed. Change the number (in this case 1) to a different number for a different pipe. The next step is to attach your port. sudo ipfw add 1 pipe 1 src-port 80 In this case anything on port 80 (http) will be set to a limit of 50Kbyte/s. If you want to attach a second port to this pipe, repeat the command but change the port number at the end. src : http://www.mactricksandtips.com/2008/12/throttling-bandwidth-on-a-mac.html

connects to a serial console
cu (call UNIX) establishes a full-duplex connection to another machine (*BSD) using a serial console. It becames more useful than screen if you have to send a BREAK signal. using cu just type "~#". $man cu http://www.openbsd.org/cgi-bin/man.cgi?query=cu&apropos=0&sektion=0&manpath=OpenBSD+Current&arch=i386&format=html

Display the definition of a shell function
Display the code of a previously defined shell function.

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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