By default, Ubuntu lists nearby wireless networks sorted alphabetically, regardless of the signal strength.

How can I set the list to be displayed in order of wi-fi signal power?

I am getting the following error on Pidgin 2.10.10-3.fc20 (libpurple 2.10.10).

How can I force it to accept an invalid certificate?

(According to this bug report it should be capable).

Here's what I have done:

• visited the domain on Firefox, and exported the certificate
• imported the certificate on Pidgin tools->certificates
• Imported the certificate on seahorse (gnome keyring GUI)

This is a followup to a question about dialog boxes.

I want to show a dialog box both at the start of a session, and after n minutes of inactivity. I have decided to use zenity and xautolock. I have success invoking both from the command line (bash).

zenity --text=text --warning
xautolock -time 15 -locker "zenity --text=sometext --warning"

However, there are some constraints:

• The text has multiple words. If it has spaces, zenity will only show the first word and try to parse the other words as parameters. To fix this, I enclose the text in double quotes ("), but it leads to:
• xautolock takes the entire zenity command as an option for its -locker parameter. The command has multiple words, so I have to enclose it in quotes. But it already had quotes originally, so it conflicts on quotes-inside-quotes.
• I want the alert text to be customizable, so I'm using --text="$(cat .filename)".

So now what I have is:

zenity --text="$(cat .filename)" --warning
xautolock -time 15 -locker "zenity --text=\"$(cat .filename)\" --warning"

If I run each line separately on a terminal session (bash), they do work. The cursor gets stalled waiting for the process to terminate, but the dialog boxes are displayed the way I need them.

Now I need it to start automatically with no user intervention. What I did:

• I've put each line separetedly on the Startup Applications list. Instead of showing the desired text, they will show $(cat on the dialog box.
• I created a command.sh file on my ~ folder, pasted these two lines, made it executable.
• Running the script from the command line works.
• Puting ~/command.sh as an entry on Startup Applications does not work. Nothing happens, nothing is displayed, no error message, nothing. According to this answer, it should work.
• Putting /home/username/command.sh does work, but this user is just a "skel" that gets copied to a guest user folder created upon login, so the username folder will be "guest-RANDOMSTRING", and I can't set is as a Startup Applications entry. For permission reasons, I can't set in to the "skel" user as well.

I am soon going to have to migrate an entire computer lab (about 50 PCs) from Windows 7 to Ubuntu 14.04 LTS. As it's an university, 99% of the time (if not 100%) it will be used by students. There is not a central database of user accounts and credentials, so each PC will have only two accounts, admin and guest, with the latter configured to autologin (besides some customization as per this tutorial).

When the PCs are turned on, and the guest account logs in automaticcaly, the first thing shown after the window manager is loaded is this dialog box:

However, there's two problems:

1. The very first person who sits at the computer at 9am will see the dialog box, click OK, use the PC, leave, not ending the session or locking the screen (because users), and the second user onwards won't see the message
2. There is more relevant information that I'd like to convey for the lab users (lab rules, etc).

So, with this scenario in mind, what I want to achieve is having a dialog box really similar to this one (but with a different text, set by me) to popup whenever a computer isn't used for, say, 15 minutes. (For the purpose of this question, let's assume "not used" means no keyboard or mouse activity).

I have been directed to How does ubuntu determine inactivity before suspending? and How can a script detect a user's idle time? and use ruby or sheel scripts, but I don't know how to code.

Is there a simpler way to achieve what I need?

Ubuntu 12.04.4 LTS. Firefox 27.0. apt-get install firefox says it is already the latest version. I know it is not true.

I have precise, precise-backports, precise-security and precise-updates on my sources.list (full contents here).

I performed (apparently successfuly) and apt-get update and still the result is the same. I was able to install a new pakage (guake) so apt is talking to the internet just fine.

apt-get upgrade says "0 packages updated, 0 new installed, 0 to be removed, 0 not-updated".

Result of apt-cache policy firefox:

firefox:
  Instalado: 27.0+build1-0ubuntu0.12.04.1
  Candidato: 27.0+build1-0ubuntu0.12.04.1
  Tabela de versão:
 *** 27.0+build1-0ubuntu0.12.04.1 0
        500 http://br.archive.ubuntu.com/ubuntu/ precise-updates/main amd64 Packages
        500 http://security.ubuntu.com/ubuntu/ precise-security/main amd64 Packages
        100 /var/lib/dpkg/status
     11.0+build1-0ubuntu4 0
        500 http://br.archive.ubuntu.com/ubuntu/ precise/main amd64 Packages

tl;dr

How can I:

1. Install Ubuntu on lots of PCs without burning lots of DVDs and installing manually
2. Have a set of preconfigured options applied to all these PCs during (or right after) install
3. Automate the way I apply configuration changes to all PCs simultaneously

What we need

We're migrating a school lab of a few dozen PCs from Windows to Ubuntu. All the PCs will have the same configuration (i.e., they might differ in hardware but will have exactly the same software, same user accounts, with same passwords, same system settings, same icons in same positions, etc). All non-maintenance users will be using the guest account.

Current scenario

Here's what I did

• Install Ubuntu 14.04 LTS on a VM.
• Set it with an admin account, a non-admin account and a guest account.
• Install all desired packages (ex: java, icedtea-plugin, flashplugin-installer).
• Install unattended-upgrades
• Use the non-admin account to:
  1. configure each software to the desired behaviour (ex: configure the Firefox start page, install AdBlock Plus and a couple addons, configure specific settings for those addons).
  2. Set the wallpaper and the Unity launcher icons and their positions. This includes a couple custom .desktop files with custom icons in ~/.icons, manually added to the launcher in specific positions.
• Set a symbolic link to use this non-admin account as a template for the guest account (every modification to it modifies the guest account).
• Set the guest account to autologin.
• Used remastersys' backup option to create an .iso. For those who don't know remastersys, the backup option creates a live session ISO that behaves exactly like the desktop system, and upon install (manual install, using ubiquity installer), keeps the same settings, including user accounts and files.

Here's the next steps in this scenario

• Manually install this ISO in each lab computer.
• Build a local mirror and configure each PC with the yet undefined mirror IP. (I don't know if it's relevant to the question, but there will be a local Ubuntu mirror (yet to be built and have its IP defined), and the PCs will have only it on their sources.list file).

Problems I'm trying to solve (or find better alternatives)

1. Before I even start installing Ubuntu on the lab PCs, I still need the extra steps of installing it on a VM, updating mirrors, upgrading packages, installing all the needed packages, setting up user accounts, changing wallpapers, installing firefox addons, configuring these addons, then creating an .iso with those settings.
2. Then I have to burn a lot of DVDs, and manually perform then install procedure for each PC lab. If there are not enough DVDs, I have to wait for the install to end on another computer so I can reuse a DVD. This can take a long time.
3. Any configuration change -- anything, from changing the wallpaper, to modifying the admin account password, to installing a new package, to changing the local mirror IP, has to be made manually on each PC. Besides unoptimal, This can lead to inconsistency.
4. Any updated software that performs some post-update procedure (ex: Firefox and its "testing addon compatibility" dialog) will keep repeating it on every guest login, until someone logins on the guest template account and runs the software.

What I have considered

I have heard one can use PXE to perform "boot installs" or "net installs", but not only I couldn't find any simple guide that I could understand, it looks like you need to extract a netboot folder from a "clean" ISO and use this to bootstrap the install; so it seems to me that all customizations I have done would go to waste and would have to be done post-install on each PC. From what I gathered you can't use a Live CD ISO to netboot, is that right? It also doesn't solve the problem of applying a single change automatically and simultaneously to all the machines when all the systems are already installed.

I have a scenario where the only user account to be used is the guest account. There's an admin account to be used only for maintenance.

I have installed unattended-upgrades; will it work as intended? Will it perform the upgrades on background while the guests are logged, or only if I periodically login as admin?

Ubuntu uses at least three different icons for identifying USB storages. What are the criteria used to diferentiate those?

For instance, I have two nearly identical Sandisk Cruzer Blade USB drives, one 4 GB and other 8 GB. (The output of lsusb is the same for both: Bus 001 Device 009: ID 0781:5567 SanDisk Corp. Cruzer Blade). On Linux, one is displayed with the flash drive icon and other with the generic USB storage icon. Sometimes a third, purple icon is used too.

What is the cause of this behavior? Are there other icons? What are the rules for Ubuntu picking different USB drive icons and what do they mean?

I'm running Ubuntu 12.04.2 32 bits.

The error doesn't show up if I start gksudo virt-manager.

• libvirt-bin is installed.
• I don't know how to check for the daemon.
• I am a member of libvirtd.

Output of ps ax | grep libvirt:

9225 ? Sl 0:04 /usr/sbin/libvirtd -d
9302 ? S 0:00 /usr/sbin/dnsmasq -u libvirt-dnsmasq --strict-order --bind-interfaces --pid-file=/var/run/libvirt/network/default.pid --conf-file= --except-interface lo --listen-address 192.168.122.1 --dhcp-range 192.168.122.2,192.168.122.254 --dhcp-leasefile=/var/lib/libvirt/dnsmasq/default.leases --dhcp-lease-max=253 --dhcp-no-override`

Output of ls -l /var/run/libvirt/libvirt-sock:

srwxrwx--- 1 root libvirtd 0 Set 13 15:04 /var/run/libvirt/libvirt-sock

Output of getent group libvirtd:

 libvirtd:x:130:OTHERUSER,MYUSER

Detailed error message

Unable to connect to libvirt.   
Failed to connect socket to '/var/run/libvirt/libvirt-sock': Permission denied

Verify that:
 - The 'libvirt-bin' package is installed
 - The 'libvirtd' daemon has been started
 - You are member of the 'libvirtd' group

Libvirt URI is: qemu:///system

Traceback (most recent call last):
  File "/usr/share/virt-manager/virtManager/connection.py", line 1185, in _open_thread
    self.vmm = self._try_open()
  File "/usr/share/virt-manager/virtManager/connection.py", line 1167, in _try_open
    flags)
  File "/usr/lib/python2.7/dist-packages/libvirt.py", line 102, in openAuth
    if ret is None:raise libvirtError('virConnectOpenAuth() failed')
libvirtError: Failed to connect socket to '/var/run/libvirt/libvirt-sock': Permission denied

The issue:

When I open the "add new project" dialog (screenshot below), I can't create a new project. The loading message (hourglass icon) stays on forever. Except for "cancel", the other buttons are disabled.

It was working fine a few days ago, I haven't changed any setting prior to the issue appearing. I ran the internal update feature, but the issue persists.

The info:

My OS version: Ubuntu 12.04.2 LTS 64 bits

Netbeans version:

Help -> about

Product Version: NetBeans IDE 7.2.1 (Build 201210100934)
Java: 1.6.0_27; OpenJDK 64-Bit Server VM 20.0-b12
System: Linux version 3.2.0-49-generic running on amd64; UTF-8; pt_BR (nb)
User directory: /home/user/.netbeans/7.2.1
Cache directory: /home/user/.cache/netbeans/7.2.1

What I tried:

• Changing the Look and Feel with the --laf command-line option. The look-and-feel does change, but the issue persists.
• Using the internal update command, a plugin got updated but the issue persists.
• Downloading and installing the latest version (7.31), it imported the settings from the previous version and the issue persists.
• Removing the settings folder ~/.netbeans/7.3.1, restarting netbeans, choosing not to import settings and rather have a new clean install

We have one office with broadband and another one with dialup. My goal is to create a local Ubuntu mirror on the second office.

I have used apt-mirror on my local machine, and it downloaded about 130GB of packages. How do I transfer these files to another computer to create a local mirror? Do I just copy the folders with the .deb files to the new machine? Do I need to edit config files or perform another action?

I have just finished installing Ubuntu 12.04.2 LTS 32 bits on my Toshiba Satellite L355D-S7809 laptop. I have performed apt-get update and upgrade and rebooted. The mouse movement on the login screen is very slow. After logging in it works fine. How can I troubleshoot it? The mouse is an USB mouse from an extremely generic brand, it works fine on Windows and on Ubuntu other than on login screen.

I have the rar package installed. Double clicking on .rar files opens the file in Archive manager. It works fine when folders or files use only characters with no accentuation, but if there is some accentuation present (inside the archives, not on the archive container filenames), then files that will open just fine in Windows using Winrar, 7zip or other archiver will produce an error message in Ubuntu.

The Archive Manager window will show the file list with wrong charsets, and trying to extract the files will produce two distinct errors:

If I double click the file:

RAR 4.00 beta 3   Copyright (c) 1993-2010 Alexander Roshal   17 Dec 2010
Shareware version         Type RAR -? for help


Extracting from /media/folder/file.rar

No files to extract

If I use the extract command:

all the files in the archive will be extracted but (invalid encoding) will be attached to the end of the folders and files with accentuation.

I have a network printer and my machine recently stopped being able to print, other machines can print fine. Besides having to use root to change its settings, when I try to change its settings I get the following error:

CUPS "client-error-not-possible".

Many forum threads suggest installing smbclient to solve the issue, but I already have it installed.

I came back to work after a week away and this is what greets me:

If I press enter it displays the tty1 login prompt.

I have booted using a 12.04.2 Live USB and it seems to work fine, I`m using it to write this.

I have no idea where to start or what to look for. There are no USB devices attached, besides mouse and keyboard. The same message shows up if I disconnect both and reboot.

Either selecting a "previous linux version" on grub, or apt-get dist upgrade doesn't solve my issue.

Here's the content of Xorg.*.log files in /var/log: https://gist.github.com/anonymous/5613488

I have a multiple monitor setup with two screens. The login screen uses dual monitor mode (as seen on the first picture), but the lock screen (CTRL + ALT + L) uses only a single monitor and disables the other (as in the second image). Is there a way to change that? I want the lock screen to extend to both monitors, if possible.

My OS is Ubuntu 12.04. Video card is "NVIDIA Corporation G98 [GeForce 8400 GS] (rev a1)", and System Settings tab "Details" shows "Driver" as "unknown".

Login screen using multi monitor mode:

Lock screen using only a single monitor:

I'm using Empathy on Ubuntu 12.04 (32 bits) to connect to "people near me", gtalk and facebook. I've been using it for about 2 weeks with no issues.

Then suddenly today the facebook account started dropping, disconnecting and reconnecting all the time. It does connect to facebook (I've found lots of other questions here but it's for people who can't connect -- I can connect and see the logged in users)

After about 20 or 30 seconds it gets disconnected, shows up a "reconnect / edit account" button on the top of the contacts list. If I either press "reconnect" or don't press it, it keeps retrying, getting reconnected, then dropping connection after a few seconds.

I have removed the account and created a new one. It appeared to have worked for about five minutes, then the issue reappeared.

I'm using Ubuntu 12.04 and NetBeans IDE 7.2.1. My system is set to pt-br, and my NetBeans installation too. I want to use Netbeans in English, how is this possible? I can't find any settings to change the language.

I'm running Ubuntu 12.04 x86. Once I had two monitors and used the Nvidia control panel to configure dual screen to get a single desktop stretched across the two monitors.

Then I had one monitor removed and now every time I login I get the following error mesage:

How do I get rid of it?