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Convert seconds to [DD:][HH:]MM:SS
Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

Mnemonic for `nice` and `renice` command
This is just a phrase I use to help me remember which way is what when using nice (top, renice, etc.), and not a command, (unless you really want this in your .bash_history to help remind you.) I was using the command `man nice ` way too much just to look up which way is what. This saves 9 keystrokes every time I remember it. Make sure you downvote me if you think mnemonics sux. Otherwise I hope this helps someone else.

Download all images from a site
This recursively downloads all images from a given website to your /tmp directory. The -nH and -nd switches disable downloading of the directory structure.

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

Generate a random password 30 characters long
Find random strings within /dev/urandom. Using grep filter to just Alphanumeric characters, and then print the first 30 and remove all the line feeds.

Random Futurama quote
Random Futurama quote from http://cubemonkey.net/quotes/. Change the quote= to change the quote source.

Create a mirror of a local folder, on a remote server
Create a exact mirror of the local folder "/root/files", on remote server 'remote_server' using SSH command (listening on port 22) (all files & folders on destination server/folder will be deleted)

Summarize the number of open TCP connections by state
Useful for checking the number and state of TCP connections.

Print entire field if string is detected in column
It searches for a specific value in the specified column and if it finds it it'll print the whole field/row. Similarly, if you don't know what you're looking for exactly but want to exclude something you're already aware of, you can exclude that "something: awk '{ if ($column != "string") print $0}'

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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