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Geolocate a given IP address

Simplification of "sed 'your sed stuff here' file > file2 && mv file2 file"

Show current pathname in title of terminal
This helps to keep track of what is going on when you have several tabs open in your terminal. The title automatically changes when you change directories.

Convert JSON to YAML

Send an email from the terminal when job finishes
Might as well include the status code it exited with so you know right away if it failed or not.

convert single digit to double digits
works only in zsh, requires autoload zmv

gets all files committed to svn by a particular user since a particular date
just change the date following the -r flag, and/or the user name in the user== conditional statement, and substitute yms_web with the name of your module

Ping sweep without NMAP
Waits for all pings to complete and returns ip with mac address

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.

A function to find the newest file in a directory


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