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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

Easy Persistent SSH Connections Using Screen
Use as: $ s host1 Will ssh to remote host upon first invocation. Then use C-a d to detatch. Running "s host1" again will resume the shell session on the remote host. Only useful in LAN environment. You'd want to start the screen on the remote host over a WAN. Adapted from Hack 34 in Linux Server Hacks 2nd Addition.

a function to find the fastest DNS server
http://public-dns.info gives a list of online dns servers. you need to change the country in url (br in this url) with your country code. this command need some time to ping all IP in list.

Mount a .iso file in UNIX/Linux
"-o loop" lets you use a file as a block device

List the size (in human readable form) of all sub folders from the current location

Bypass with hexencoding, dump /etc/passwd

Delete line number 10 from file
Very useful when the ssh key of a host has changed and ssh refuses to connect to the machine, while giving you the line number that has changed in ~/.ssh/known_hosts.

small CPU benchmark with PI, bc and time.
$ # 4 cores with 2500 pi digits $ CPUBENCH 4 2500 $. $ every core will use 100% cpu and you can see how fast they calculate it. $ if you do 50000 digitits and more it can take hours or days

Setting global redirection of STDERR to STDOUT in a script
You have a script where =ALL= STDERR should be redirected to STDIN and you don't want to add "2>&1" at the end of each command... E.G.: $ ls -al /foo/bar 2>&1 Than just add this piece of code at the beginning of your script! I hope this can help someone. :)

kill process by name
Or even easier, if it's available: $ killall firefox I have no idea why you would want to rely on two unusual dependencies to do something that can be done a hundred ways from coreutils...


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