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Random Number Between 1 And 256
It takes a byte from /dev/random whose source is the kernel entropy pool (better source than other solutions).

Post a message to another users screen via SSH
Post a message on another users screen via SSH

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

Convert DOS newlines (CR/LF) to Unix format
Convert DOS newlines (CR/LF) to Unix format using sed command

Kill a process by its partial name (BSD/Mac)
This kills Activity Monitor

grep (or anything else) many files with multiprocessor power
Parallel does not suffer from the risk of mixing of output that xargs suffers from. -j+0 will run as many jobs in parallel as you have cores. With parallel you only need -0 (and -print0) if your filenames contain a '\n'. Parallel is from https://savannah.nongnu.org/projects/parallel/

watch your network load on specific network interface
-n means refresh frequency you could change eth0 to any interface you want, like wlan0

Turn white color to transparent for a series of png images
mogrify can be used like convert. The difference is that mogrify overwrites files: http://www.imagemagick.org/www/mogrify.html Of course, other source colors can be used as well.

Sync MySQL Servers via secure SSH-tunnel
I wanted to keep a backup of my company database server on my local homeserver. After I found maatkit to sync databases, everything except security seemed fine. SSH takes care of that part.

SSH Copy ed25519 key into your host


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