Commands by Bonster (27)

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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"

Search big files with long lines
This is a handy way to circumvent the "Maximum line length of 2048 exceeded" grep error. Once you have run the above command (or put it in your .bashrc), files can be searched using: $ lgrep search-string /file/to/search

Securely destroy data (including whole hard disks)
GNU shred is provided by the coreutils package on most Linux distribution (meaning, you probably have it installed already), and is capable of wiping a device to DoD standards. You can give shred any file to destroy, be it your shell history or a block device file (/dev/hdX, for IDE hard drive X, for example). Shred will overwrite the target 25 times by default, but 3 is enough to prevent most recovery, and 7 passes is enough for the US Department of Defense. Use the -n flag to specify the number of passes, and man shred for even more secure erasing fun. Note that shredding your shell history may not be terribly effective on devices with journaling filesystems, RAID copies or snapshot copies, but if you're wiping a single disk, none of that is a concern. Also, it takes quite a while :)

Set laptop display brightness
Run as root. Path may vary depending on laptop model and video card (this was tested on an Acer laptop with ATI HD3200 video). $ cat /proc/acpi/video/VGA/LCD/brightness to discover the possible values for your display.

Clear terminal Screen
Probably the quickest / easiest way to clear the screen.

Command to Show a List of Special Characters for bash prompt (PS1)
I use this command (PS1) to show a list bash prompt's special characters. I tested it against A flavor of Red Hat Linux and Mac OS X

Generate QR code for a WiFi hotspot
Prompts for network name (SSID) and password, and generates (as qr-wifi.png) a WiFi QR code (e.g. "WIFI:S:mynet;T:WPA;P:mypass;;" for mynet/mypass). Dependencies [sudo apt-get install]: qrencode zenity

execute your commands hiding secret bits from history records
$ wget --user=username --password="$password" http://example.org/ Instead of hiding commands entirely from history, I prefer to use "read" to put the password into a variable, and then use that variable in the commands instead of the password. Without the "-e" and "-s" it should work in any bourne-type shell, but the -s is what makes sure the password doesn't get echoed to the screen at all. (-e makes editing work a bit better)

grep for minus (-) sign
Use flag "--" to stop switch parsing

Use xdg-open to avoid hard coding browser commands
I rarely use the system menu to start applications. I use keyboard shortcuts instead. Keyboard shortcuts are convenient time savers. To configure the shortcuts I use gconf-editor or CompizConfig Settings Manager (if I have Compiz turned on). Lately I've been using Chromium as my browser. Since Chromium is under heavy development it occasionally becomes unusable and I have to switch back to Firefox. I was hard-coding the browser command in my keyboard shortcuts. This became problematic with frequent browser hopping. I now use the xdg-open command when defining my keyboard shortcuts. xdg-open opens a file or URL in the user's preferred application. In the metacity keybinging_commands I have xdg-open http://gmail.com where I used to have firefox http://gmail.com. Now when switching browsers I don't have to update each keyboard binding command I just change my default browser in Ubuntu by clicking through the menu: System / Preferences / Preferred Applications / Web Browser. xdg-open is more convenient for this browser hopper.


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