Commands by chrisp6825 (1)

What's this? is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

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Encrypt and password-protect execution of any bash script, Version 2
(Please see sample output for usage) Use any script name (the read command gets it) and it will be encrypted with the extension .crypt, i.e.: myscript --> myscript.crypt You can execute myscript.crypt only if you know the password. If you die, your script dies with you. If you modify the startup line, be careful with the offset calculation of the crypted block (the XX string). Not difficult to make script editable (an offset-dd piped to a gpg -d piped to a vim - piped to a gpg -c directed to ), but not enough space to do it on a one liner. Sorry for the chmod on parentheses, I dont like "-" at the end. Thanks flatcap for the subshell abbreviation to /dev/null

search installed files of package, that doesn't remember his name well. On rpm systems
rpm, sometimes, is not wildcard friendly. To search files installed from package this could be useful. change PACKAGENAME to any package do you want to search

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 The command is untested under any other distros or less outdated kernels.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.

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

Convert Youtube videos to MP3
youtube-dl has this functionality built in. If you're running an older version of youtube-dl, you can update it using `youtube-dl -U` (although if you have an older version, it probably doesn't download youtube videos anyway.) youtube-dl --help will show you other options that may come in useful.

Debug bash shell scripts.
Display commands and their arguments as they are executed. Useful for debugging shell scripts.

use screen as a terminal emulator to connect to serial consoles
Use GNU/screen as a terminal emulator for anything serial console related. screen /dev/tty eg. screen /dev/ttyS0 9600 MacOSX: Cheat Sheet:

print java packages by using unix tree and sed
if you need a quick way of printing out all the packages that contain classes this command will print the directory structure and replace '/' with '.' It will also ignore CVS directories (we use CVS here)

Given process ID print its environment variables
Same as previous but without fugly sed =x

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"

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