Commands tagged random (98)

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Redirect incoming traffic to SSH, from a port of your choosing
Stuck behind a restrictive firewall at work, but really jonesing to putty home to your linux box for some colossal cave? Goodness knows I was...but the firewall at work blocked all outbound connections except for ports 80 and 443. (Those were wide open for outbound connections.) So now I putty over port 443 and have my linux box redirect it to port 22 (the SSH port) before it routes it internally. So, my specific command would be: $iptables -t nat -A PREROUTING -p tcp --dport 443 -j REDIRECT --to-ports 22 Note that I use -A to append this command to the end of the chain. You could replace that with -I to insert it at the beginning (or at a specific rulenum). My linux box is running slackware, with a kernel from circa 2001. Hopefully the mechanics of iptables haven't changed since then. The command is untested under any other distros or less outdated kernels. Of course, the command should be easy enough to adapt to whatever service on your linux box you're trying to reach by changing the numbers (and possibly changing tcp to udp, or whatever). Between putty and psftp, however, I'm good to go for hours of time-killing.

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"

Generate random password
Generates password consisting of alphanumeric characters, defaults to 16 characters unless argument given.

processes per user counter
use Linux ;)

Analyze awk fields
Breaks down and numbers each line and it's fields. This is really useful when you are going to parse something with awk but aren't sure exactly where to start.

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

mhwd ? Manjaro Hardware Detection
One base component is our hardware detection. It is a C++ library and app and is designed after a dynamic structure. Any kind of hardware, no matter if usb or pci, can be configured by mhwd. There is just a simple configuration file which tells mhwd what to do. This way we also support hybrid graphics cards out of the box. However there are currently only mhwd configs for nvidia optimus setups. But this gap will be filled soon. Just play with some of those commands to get a feeling about mhwd.

Record and share your terminal
It replays plain text terminal screencast from http://shelr.tv/

Monitor a file with tail with timestamps added
Should be a bit more portable since echo -e/n and date's -Ins are not.

Convert PDF to JPEG using Ghostscript
Converting your PDF file to JPEG images. You can set resolution by -r option (default: 72dpi).


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