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Merge files, joining each line in one line
Merge files, joining line by line horizontally. Very useful when you have a lot of files where each line represents an info about an event and you want to join them into a single file where each line has all the info about the same event See the example for a better understanding

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

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

Bruteforce Synology NAS Logins with Hydra

Rename files in batch

Debug pytest failures in the terminal
pudb is an ncurses debugger. This command will allow interactive debugging of test failures in pytest using pudb.

convert single digit to double digits
Uses 'rename' to pad zeros in front of first existing number in each filename. The "--" is not required, but it will prevent errors on filenames which start with "-". You can change the "2d" to any number you want, equaling the total numeric output: aka, 4d = ????, 8d = ????????, etc. I setup a handful of handy functions to this effect (because I couldn't figure out how to insert a var for the value) in the form of 'padnum?', such as: padnum5 () { /usr/bin/rename 's/\d+/sprintf("%05d",$&)/e' -- $@ } Which would change a file "foo-1.txt" to "foo-00001.txt"

Remove specific versions of old kernels (Ubuntu/Debian)
If, for example, you want to remove all kernels and headers but the last three versions, you can't use one of that magic all-in-one "remove old stuff" commands. With this simple but elegant command you can remove a range of versions, or a list of versions with e.g. {14,16,20}.

Backup with versioning

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


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