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Command Line HowTo Linux Ubuntu

what(): Serial Port failed to open: open: Permission denied

what():  Serial Port failed to open: open: Permission denied

Trying to get access to your serial port without the need for running whatever program as sudo or root? You’re probably not in the dialout group, if that’s the case, here’s the fix:

First, check you aren’t in the group:

groups alex

This will list all the groups the user is in, here the user is called ‘alex’, just substitute that for your own username. If the output doesn’t contain the dialout group, keep going. If it does, you might have another issue which this isn’t likely to solve.

sudo gpasswd --add alex dialout

This command will add the user ‘alex’ to the ‘dialout’ group. Once that’s done you’ll need to logout and back in again for the effects to take place.

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Command Line HowTo Linux Ubuntu

fatal error: libconfig.h: No such file or directory | Ubuntu 12.04

If you’re getting the following error:

fatal error: libconfig.h: No such file or directory

Then you’re probably missing the libconfig-dev package from your system. Simply run the following command and it’ll fix it:

sudo apt-get install libconfig-dev
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Linux Ubuntu

gimp: error while loading shared libraries: libgegl-0.0.so.0: cannot open shared object file: No such file or directory

After upgrading from Ubuntu 11.10 to 12.04 I found gimp couldn’t access the shared libraries it needed, most likely an error with symbolic links as described by lovelyindia in this post.

Fix 1:

He managed to fix the issue by removing gimp and purging the offending libraries and then letting apt deal with the libraries when he re-installed gimp, as per the below commands:

sudo apt-get update 
sudo apt-get purge gimp libgegl* libbabl* 
sudo apt-get install gimp 
sudo apt-get clean

While this is likely to work for most people encountering this issue, it didn’t for me.

Fix 2:

Then I remembered I had used the repogen source list generator, in which I chose to include the gimp svn build. While you may not have gone about it the same way, you may also have a different repository in your sources.list file which is causing this issue, if the previous method did not resolve the issue.

In order to fix this, I had to open the sources.list file and comment out the offending repo.

sudo gedit /etc/apt/sources.list

Now search for any reference to gimp, in my case this was the lines I changed:

#### Gimp SVN - https://launchpad.net/~matthaeus123/+archive/mrw-gimp-svn
## Run this command: sudo apt-key adv --recv-keys --keyserver keyserver.ubuntu.com 405A15CB
deb http://ppa.launchpad.net/matthaeus123/mrw-gimp-svn/ubuntu precise main

I commented out the line linking to the repo by adding a ‘#’ to the front, as below:

#### Gimp SVN - https://launchpad.net/~matthaeus123/+archive/mrw-gimp-svn
## Run this command: sudo apt-key adv --recv-keys --keyserver keyserver.ubuntu.com 405A15CB
# deb http://ppa.launchpad.net/matthaeus123/mrw-gimp-svn/ubuntu precise main

I then uninstalled gimp, once I knew it may have been the newly added repository that I had added:

sudo apt-get purge gimp

Then I saved and exited the file and updated apt:

sudo apt-get update

I then re-installed gimp:

sudo apt-get install gimp

This solved the issue for me, I hope this helps!

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Command Line Linux Ubuntu

Ubuntu 12.04 – Removing conflicting operating system files…

If you’re trying out the latest version of Ubuntu, 12.04 or Precise Pangolin and you want to keep your old /home partition, chances are you’ve come across the installation hanging on a process “Removing conflicting operating system files…”. No worries, this seems to be a common bug and there’s a pretty easy work around.

Continue with the installation, without asking for the /home partition to be mounted. Only set the root partition (/) and your swap space.

Once the installation is complete, reboot and load it up.

Now, you’ll want to find the partition that /home is mounted under, this will likely be /dev/sdxN, where x is the drive letter and N is the partition number (i.e mine is located under /dev/sda5).

If you’re unsure, you can list the possible drives using the following command:

ls /dev/ | grep sd

And then you can mount each drive under in a temp directory and check what’s in there:

mkdir temp
mount /dev/sda1 temp

Once you know which partition you want, it’s time to edit your /etc/fstab/

sudo gedit /etc/fstab

For those who don’t go digging around in the config files of linux, this may look pretty daunting, but it isn’t. All you really need to do is add a new line to mount your home partition. Here’s mine:

/dev/sda5	/home/		ext4	defaults	1	2

The first part is the partition that’s being used, next what the partition is. Next is the file system type. Followed by default options and then the dump and pass values.

Once you’ve saved this file with the appended line, reboot your system. Now you should find your old home partition is mounted normally and you can get on with your install.

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Command Line Linux Ubuntu

Ubuntu 12.04 – Moving The Windows Buttons Back To The Right.

Those pesky windows buttons (maximise, minimise and close) default to the left of the menu bar after a new Ubuntu installations, and it’s been happening since 10.04. Most people, like myself, are stuck in our ways and just want them back where they belong. It’s pretty easy to do this, just open up a terminal (ctrl+alt+t) and copy in the following:

gconftool -s /apps/metacity/general/button_layout -t string menu:minimize,maximize,close

Once you hit enter, you should see the buttons return to their rightful place on the right, also in the right order.