Commands tagged date (113)

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remove repeated pairs of characters e.g. "xtxtxtxt" will become "xt"
This will remove repeated characters e.g. echo "xtxtxtxt" | sed -ru 's/(..)\1{2,}/\1/g' the output will just be "xt"

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

Output entire line once per unique value of the first column
Removes duplicates in the specified field/column while outputting entire lines. An elegant command for processing tab (or otherwise) delimited data.

Rename files in batch

Find usb device in realtime
Using this command you can track a moment when usb device was attached.

Encrypted chat with netcat and openssl (one-liner)
client$ while true; do read -n30 ui; echo $ui |openssl enc -aes-256-ctr -a -k PaSSw ; done | nc localhost 8877 | while read so; do decoded_so=`echo "$so"| openssl enc -d -a -aes-256-ctr -k PaSSw`; echo -e "Incoming: $decoded_so"; done This will establish a simple encrypted chat with AES-256-CTR using netcat and openssl only. More info here https://nixaid.com/encrypted-chat-with-netcat/

Create a new file

Search through files, ignoring .svn
By putting the "-not \( -name .svn -prune \)" in the very front of the "find" command, you eliminate the .svn directories in your find command itself. No need to grep them out. You can even create an alias for this command: $ alias svn_find="find . -not \( -name .svn -prune \)" Now you can do things like $ svn_find -mtime -3

Read and write to TCP or UDP sockets with common bash tools
Ever needed to test firewalls but didn't have netcat, telnet or even FTP? Enter /dev/tcp, your new best friend. /dev/tcp/(hostname)/(port) is a bash builtin that bash can use to open connections to TCP and UDP ports. This one-liner opens a connection on a port to a server and lets you read and write to it from the terminal. How it works: First, exec sets up a redirect for /dev/tcp/$server/$port to file descriptor 5. Then, as per some excellent feedback from @flatcap, we launch a redirect from file descriptor 5 to STDOUT and send that to the background (which is what causes the PID to be printed when the commands are run), and then redirect STDIN to file descriptor 5 with the second cat. Finally, when the second cat dies (the connection is closed), we clean up the file descriptor with 'exec 5>&-'. It can be used to test FTP, HTTP, NTP, or can connect to netcat listening on a port (makes for a simple chat client!) Replace /tcp/ with /udp/ to use UDP instead.

Check if a command is available in your system
Usefull to detect if a commad that your script relies upon is properly installed in your box, you can use it as a function function is_program_installed() { type "$1" >/dev/null } Invoke it and check the execution code is_program_installed "dialog" if [ ! $? -eq 0 ]; then echo "dialog is not installed" exit 1 fi


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