Commands by unixhome (6)

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start a VNC server for another user

purge all packages marked with 'rc'
After you install/remove lots of packages, there are many packages marked with 'rc'. This script help you to purge these packages, it will save some spaces from your disk.

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

Print Memory Utilization Percentage For a specific process and it's children
Change the name of the process and what is echoed to suit your needs. The brackets around the h in the grep statement cause grep to skip over "grep httpd", it is the equivalent of grep -v grep although more elegant.

List manually installed packages (excluding Essentials)

Backup with versioning
Apart from an exact copy of your recent contents, also keep all earlier versions of files and folders that were modified or deleted. Inspired by the excellent EVACopy http://evacopy.sourceforge.net

ettercap..
There weren't any one liners for ettercap on this site... tisk tisk :-) (of course you'll have to plugin your own values for the variables..)

Performance tip: compress /usr/
Periodically run the one-liner above if/when there are significant changes to the files in /usr/ = Before rebooting, add following to /etc/fstab : = $ /squashed/usr/usr.sfs /squashed/usr/ro squashfs loop,ro 0 0 $ usr /usr aufs udba=reval,br:/squashed/usr/rw:/squashed/usr/ro 0 0 No need to delete original /usr/ ! (unless you don't care about recovery). Also AuFS does not work with XFS

The wisdom of Cave Johnson
There's been a similar Futurama thing around for a while, which grabs a quote from the /. headers [curl -Ism3 slashdot.org | egrep "^X-(F|B|L)" | cut -d \- -f 2- | fmt -w $(tput cols)]. Same deal, but more likely to stop working when someone forgets to pay the bill on the domain. Until then: Cave Johnson!

Resize all JPEGs in a directory
This command requires the imagemagick libraries and will resize all files with the .jpg extension to a width of 1024 pixels and will keep the same proportions as the original image.


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