Wednesday, 9 June 2010

Sysadmin: an exercise in being functionally lazy.

I'm sitting on my couch, working really hard on my laptop. Everything is perfectly arranged around me while I study.

The linux box sitting 15 feet away from me has an internet radio station playing on amarok. The next song comes on, and it's louder than the other songs.

I really don't want to get up.

Surely some linux user has had this grave problem before. I was about to do a google search for an app on my Windows 7 laptop that would do it, then i realized I already had Putty set up to connect to my pc. All I need is the command for the command line.

To reduce your volume 15%
aumix -v-15
Too much? Increase 5%
aumix -v+15
(You may need to install the aumix package to use the commands above)
apt-get install aumix

I'm sure there's many other ways to pull this off (it is Linux, after all). Feel free to share if you have one!

Monday, 1 March 2010

How to Mount an ISO file

One of the things I love about Linux is many solutions are already made. Sometimes you need a little skill to piece together ready-made solutions, but many times they're already there.

For example, you have an .iso file, but don't want to burn it yet. You just want to see its contents.

Create a directory where you will view the iso:
mkdir /media/myiso
Then mount it:
mount -t iso9660 -o loop image.iso /media/myiso
The iso I used had spaces in the filename, so I just used
mount -t iso9660 -o loop "my image.iso" /media/myiso
(which works.)

Monday, 25 January 2010

Combine multiple images or multiple single-page PDFs into a multipage PDF

This method requires installing a (great) image-manipulation package, and using the command line, but it's very simple - suitable for someone new to using a command line.

If you do a lot of work with images, or have to do a lot of repetitive work or batch processing, I really recommend looking into ImageMagick. You can do things like make thumbnails of a certain size out of a directory, with just a few words.

Get Imagemagick if you don't have it already.
Open a commmand prompt and install ImageMagick:
apt-get install imagemagick
Now to combine your images into a multi-page PDF:
Go to the directory where are your images are.
cd /home/computername/pics
Convert the JPG files to PDF:
convert *.jpg foo.pdf
It will create a multi-page PDF, named foo.pdf in the directory you're in. Just make up whatever name you like for "foo". The pages will be arranged by alphabetical order (the filename). This method will use ALL of the jpg's in the directory. If you aren't familiar with using wildcards (*, ?) or are unfamiliar with command line, I recommend making a directory that only has the files you want to use, and put it in your /home directory so it's easy to find. If you want to only include files that differ by a letter, you can use something like
convert sample?.jpg samplepkg.pdf
...which will only place files like sample1.jpg, sample2.jpg, sample3.jpg in the pdf.

I have noticed the file size gets pretty large using this method. There are probably some command line options to set to manipulate this. Something that does make it smaller is using a graphics program like Gimp, and using the "print" option to "print to" a pdf. Then you can use the command line to combine the single page pdf's into a multipage single pdf.
convert *.pdf multi.pdf
"*" means everything, so keep in mind it will use every pdf in that directory to make a new one... even if it's multipage!

Thursday, 7 January 2010

Common Ubuntu Keyboard Shortcuts

I've finally started on my Network Technology course, where I will be doing and MCSE, CCNA, and possibly prepping for a Linux+, all in the next eight months. Stay tuned for some more interesting tidbits on the blog as I have time.

On another note, I am aware of some OS keystroke shortcuts, but had the urge to use more. Why don't I know the one for Show Desktop, for instance (it's Ctrl-Alt-D). You can also map keyboard shortcuts, which is really handy if you want to use something like the Windows key.

  • Win+E - Shows all workspaces in a nifty way and lets you switch between workspaces easily.
  • Alt+Ctrl+Left/Right Arrow – Move to Workspace on Left/Right
  • Alt+Ctrl+Shift+Left/Right Arrow – Move current window to another workspace
  • Alt + Shift+ Up Arrow – This initiates a cool looking window switcher interface with which you can switch between windows using Arrow keys while holding Alt + Shift
  • Alt+F9/F10 – Minimize/ Maximize current window
  • Alt+F5 – UnMaximizes Current Window
  • Alt+F7 – This shortcut activates the move window option that lets you move current window using arrow keys. You can even move window to other workspace, try moving it to extreme right.
  • Alt+F8 – Resize current window with arrow keys
  • Ctrl + Alt + D – Show Desktop/ Restore open windows if show desktop used earlier
  • Alt+Shift+Tab – Switch Windows in Reverse Direction as done using Alt+Tab
  • Shift+Ctrl+N – Create New Folder, Very useful shortcut
  • Alt + Enter – Show properties of a selected file/folder without requiring to right click on it and select Properties.
  • Ctrl + 1/2 – Change folder view to icon/list.
  • Ctrl + W – close current Nautilus Window
  • Ctrl + Shift + W – close all open Nautilus Windows
  • Ctrl+T – Open a new tab in Nautilus
  • Alt + Up/Down Arrow – Move to Parent Folder/ Selected folder
  • Alt + Left/Right Arrow – Move Back/forward in Nautilus
  • Alt + Home – Move directly to your Home Folder
  • F9 – Toggle display of Nautilus Sidepane
  • Ctrl + H – Toggle Display of hidden files and folders
  • Ctrl + Alt + L - Quick shortcut to Lock Screen if you need to be away from your desktop for few moments and don’t want others to see your desktop.
  • Alt + F1 – Open Applications Menu
  • Alt + F2 – Open the Run Application dialog Box
  • Win + Mousewheel – Zoom in / Zoom out Desktop. This one’s pretty useful if you are having a wireless keyboard/mouse.
(shamelessly stolen from TechnoTraits... if you found these of use, be a sport and visit them!)