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Poor man's ntpdate
If you don't have netcat, you can use curl.

Given process ID print its environment variables

Prevent non-root users from logging in
Also with optional message: $ echo "no login for you" > /etc/nologin (This doesn't affect your current X session - you're already logged in!)

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

For finding out if something is listening on a port and if so what the daemon is.
See what's listening on your IPv4 ports on FreeBSD.

Shrink more than one blank lines to one in VIM.

Switch all connected PulseAudio bluetooth devices to A2DP profile
Tries to switch all audio devices to the A2DP profile for optimal sound quality. Useful for bluetooth speakers and headphones that always power up in HSP/HFP mode. Note however that this command is only a shorthand for the GUI, so it cannot fix stubborn BT controllers that leave your device stuck in HSP mode until a manual re-coupling.

Change active bond slave
This forces a bonded interface to switch to another slave in the bond as its active slave.

Quick way to sum every numbers in a file written line by line
If you have a file full of numbers written line by line, you can sum every line to get the total. With a file like this: 3443535 9878977 67554 987798 232324 you will got: 14610188

check open ports without netstat or lsof


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