Commands by hans (3)

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Print a file to a LPD server
You don't need cups =)

A random password generator

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.

Create named LUKS encrypted volume
You need to be root to do this. So check the command before running it. You enter the same password for Enter LUKS passphrase: Verify passphrase: Enter passphrase for /dev/loopn: ___ You can then copy the .img file to somewhere else. Loop it it with losetup -f IMAGENAME.img and then mount it with a file manager (eg nemo) or run mount /dev/loopn /media/mountfolder Acts similar to a mounted flash drive

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

renice by name

Install pip with Proxy
Installs pip packages defining a proxy

Securely destroy data on given device
Intentional hash in the beginning. May run a looong time. Wipes your data for real. Was meant to be /dev/urandom - I mistyped it. :-)

Convert CSV to JSON
Replace 'csv_file.csv' with your filename.

list block devices
Shows all block devices in a tree with descruptions of what they are.


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