Commands using hostname (15)

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Comma insertions
Insert a comma where necessary when counting large numbers. I needed to separate huge amounts of packets and after 12+ hours of looking in a terminal, I wanted it in readable form.

Ping a URL sending output to file and STDOUT
The tee (as in "T" junction) command is very useful for redirecting output to two places.

distribution specific information

Write comments to your history.
A null operation with the name 'comment', allowing comments to be written to HISTFILE. Prepending '#' to a command will *not* write the command to the history file, although it will be available for the current session, thus '#' is not useful for keeping track of comments past the current session.

locate a filename, make sure it exists and display it with full details
use the locate command to find files on the system and verify they exist (-e) then display each one in full details.

Create a Multi-Part Archive Without Proprietary Junkware
Leave it to a proprietary software vendor to turn a cheap and easy parlor trick into a selling point. "Hey guys, why don't we turn our _collection of multiple files_ into a *collection of multiple files*!!" Extract the ^above with this: $ cat pics.tar.gz.??? | tar xzv ^extract on any Unix - no need to install junkware! (If you must make proprietary software, at least make it do something *new*) if [ -e windows ]; then use 7-Zip

What is my public IP-address?
Very effective, use only DNS protocol. The @ part is optional if you already set opendns servers as default ns servers.

Repeat a command until stopped
In this case it runs the command 'curl localhost:3000/site/sha' waiting the amount of time in sleep, ie: 1 second between runs, appending each run to the console. This works well for any command where the output is less than your line width This is unlike watch, because watch always clears the display.

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

Using awk to sum/count a column of numbers.
Takes a input file (count.txt) that looks like: 1 2 3 4 5 It will add/sum the first column of numbers.


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