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Awk: Perform a rolling average on a column of data
Sometimes jittery data hides trends, performing a rolling average can give a clearer view.

Ping scanning without nmap
Usefull for when you don't have nmap and need to find a missing host. Pings all addresses from 10.1.1.1 to 10.1.1.254, modify for your subnet. Timeout set to 1 sec for speed, if running over a slow connection you should raise that to avoid missing replies. This will clean up the junk, leaving just the IP address: for i in {1..254}; do ping -c 1 -W 1 10.1.1.$i | grep 'from' | cut -d' ' -f 4 | tr -d ':'; done

Countdown Clock
The biggest advantage over atoponce's nifty original is not killing the scrollback. Written assuming bash, but shouldn't be terribly difficult to port to other shells. S should be multiple spaces, but I can't get commandlinefu to save/show them properly, any help?

Get MAC address

Calculate days on which Friday the 13th occurs (inspired from the work of the user justsomeguy)
Friday is the 5th day of the week, monday is the 1st. Output may be affected by locale.

Decreasing the cdrom device speed
Decreasing the cdrom device speed may be more comfortable to watch films (for example)

fix flash video (flv) file (ffmpeg)
Rebuild flv files that are broken (can't seek). This method probably works for other video/audio formats that can become broken in the same way.

Convert any sequence of spaces/tabs to single space/tab
Remove empty lines additionally: $ tr -s ' \t\n' 2.txt identical with: $ tr -s '[:space:]' 2.txt To "clean perfectly" a text or code file, You can combine this command with another one: $ while read l; do echo -e "$l"; done 2.txt (= remove all leading and trailing spaces or tabs from all lines of a text file)

Broadcast your shell thru port 5000
Doesn't work so well if you connect from windows. Linux only sends LF where windows wants CRLF. The alternative command works better with windows, however it uses script and a named pipe.

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


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