190
votes
15answers
71k views

How to change tooltip background color in Unity?

In a lot of applications the tooltips are just plain ugly (White text on black background, way too much contrast) or even unreadable (black or dark blue text (Hyperlinks) on black background). I want ...
190
votes
6answers
178k views

How is the /tmp directory cleaned up?

How is the /tmp directory cleaned up? Is it automatic? If so, how frequently is it cleaned up?
189
votes
5answers
167k views

How can I accept the Microsoft EULA agreement for ttf-mscorefonts-installer?

After a recent update, ttf-mscorefonts-installer prompted me to accept its license agreement. For some reason my terminal will not allow me to accept, or for some reason I am pressing the wrong ...
188
votes
8answers
542k views

Screen Resolution Problem with Ubuntu 14.04 and VirtualBox

Environment: Lenovo T530 running Windows 7. Have installed Ubuntu 14.04 on a virtual machine using VM Virtual Box. Have installed all the updates from both Virtual Box and Ubuntu. Problem: While in ...
186
votes
11answers
210k views

How to really clear the terminal?

I can issue the clear command or press Ctrl + L to clear the current Ubuntu terminal, but this just shifts previous output upwards and if you use mouse scroll or PgUP and PgDown keys it's hard to ...
185
votes
14answers
119k views

How to backup settings and list of installed packages

If I want to make a backup of everything I have done since the fresh install of Ubuntu, what are the possible options? What all should I backup? I want to get all the settings that I changed, all the ...
185
votes
16answers
148k views

What's the difference between Google Chrome and/or Chromium? What are the advantages/disadvantages to each?

I used Google Chrome in Windows, and am now using Chromium in Ubuntu. Is there any difference to the two programs? What are the advantages and disadvantages to each program? Which one seems better?
184
votes
23answers
220k views

How can I install software or packages without Internet (offline)?

I have a friend who has got a computer that is not connected to the Internet. Is there any way to install software offline easily?
184
votes
6answers
224k views

How can I recursively delete all files of a specific extension in the current directory?

How do I safely delete all files with a specific extension (e.g. .bak) from current directory and all subfolders using one command-line? Simply, I'm afraid to use rm since I used it wrong once and now ...
184
votes
6answers
143k views

How can I install just security updates from the command line?

sudo apt-get upgrade installs all updates, not just security updates. I know that I can use Update Manager to select only important security updates, but is there a way to do this from the command ...
183
votes
4answers
84k views

Why did the command “:(){ :|: & };:” make my system lag so badly I had to reboot?

DANGER! Do not run this command to 'test' it unless you are prepared for a crash and/or force-rebooting your system. I was in my Virtualbox running 12.04 trying to compile an app, and while ...
182
votes
5answers
360k views

How to increment a variable in bash?

How to increment a numeric variable in bash? I tried with var=$var+1 and var=($var+1) but it doesn't work. My variable is a number, but bash think that is a string. My bash version is 4.2.45(1)-...
182
votes
23answers
149k views

How can I deactivate Bluetooth on system startup?

How can I deactivate Bluetooth on system startup?
181
votes
13answers
569k views

How to force a clock update using ntp?

I am running Ubuntu on an ARM based embedded system that lacks a battery backed RTC. The wake-up time is somewhere during 1970. Thus, I use the NTP service to update the time to the current time. I ...
181
votes
32answers
309k views

Ubuntu gets stuck in a login loop

My Ubuntu is stuck in a login loop when trying to enter my desktop. When I login, the screen gets black and soon after that the login screen comes back. I've read that the problem might be caused by ...
178
votes
36answers
142k views

What lenses for Unity are available?

This question is present as a matter of historical interest. While you are encouraged to help maintain its answers, please understand that "big list" questions are not generally allowed on AskUbuntu ...
177
votes
10answers
128k views

How to prevent updating of a specific package?

Because of bug #693758 I'd like to prevent apt-get upgrade and Update Manager from updating the "libgtk2.0-0" package. How can this be achieved?
177
votes
1answer
333k views

How do I configure swappiness?

I need a step-by-step, simple and easy way to configure swappiness.
176
votes
1answer
311k views

Installed Teamviewer using a 64-bits system, but I get a dependency error

I was trying to install Teamviewer, but I was getting a dependency error. I tried to install them, but with no luck. I'm getting this error: Unpacking teamviewer (from teamviewer_linux_x64.deb) ... ...
174
votes
10answers
157k views

How can I stop being prompted to unlock the 'default' keyring on boot?

Whenever Ubuntu boots up, a dialogue pops up asking me to unlock my default keyring. Is there some way this can unlock automatically through PAM or some other magical way?
173
votes
46answers
851k views

Installing Broadcom Wireless Drivers

I'm having serious problems installing the Broadcom drivers for Ubuntu. It worked perfectly on my previous version, but now, it is impossible. What are the steps to install Broadcom wireless drivers ...
173
votes
2answers
243k views

How do I install different (upgrade or downgrade) PHP version in still supported Ubuntu release?

I am trying to update to install PHP 5.5, 5.6 or 7.0 in Ubuntu 12.04/14.04/16.04 LTS, and I can only get PHP 5.3.10 for Ubuntu 12.04, PHP 5.5.9 for Ubuntu 14.04 or PHP 7.0.4 for Ubuntu 16.04 using ...
172
votes
5answers
144k views

How can I get octal file permissions from command line?

There is a chmod command to set file permissions, but can I get file permissions in octal mode (such as 755) from the command line?
172
votes
4answers
441k views

How to create a soft or symbolic link?

I am installing p4v in /opt, but /usr/bin is on my path. Is it possible to create a soft or symbolic link for p4v from /opt to /usr/bin, so I can just type "p4v" since /usr/bin is in my path?
171
votes
2answers
171k views

How do I retrieve the public key from a SSH private key?

A SSH private key as generated by ssh-keygen contains a public key part. How do I retrieve this public key from the private key? I've lost my public key and need to put the contents of this public key ...
170
votes
10answers
185k views

How to merge several PDF files?

There are a lot of software in Windows to merge PDF files but how can we do the same in Ubuntu?
169
votes
24answers
100k views

Do I need to have 'antivirus software' installed? [closed]

I thought that there was no need to scan for viruses either in Ubuntu or any Linux distros until I found virus scanner packages 'clamtk' and 'klamav' in Ubuntu software center yesterday. This leads ...
168
votes
6answers
126k views

How do I enable or disable Apport?

The system crash dialog is annoying me, how can I turn it off? I'd also like to know how to turn it back on just in case I need it to report a problem.
168
votes
14answers
58k views

How to customize the Ubuntu Live CD?

I would like to customize Ubuntu live CD by installing some additional packages. I have followed this but it doesn't seems to work. Can anyone provide clear instructions? Note: I do not prefer ...
167
votes
4answers
226k views

What do the different colors mean in the terminal?

What do the different colours in Ubuntu's terminal mean? For example, when I type the ls command in one of my folders, I get one of the files in light green, the other (which is a folder) in blue with ...
164
votes
19answers
145k views

I have 16GB RAM. Do I need 32GB swap?

I read many places that the rule of thumb for swap space is to double the amount of physical RAM. However, 32 GB does seem a LOT. Do I need that much? Do I need it at all with this high amount of ...
163
votes
10answers
588k views

How to use “grep” command to find text including subdirectories

I want to find all files which contain a specific string of text. The grep command works, but I don't know how to use it for every directory (I can only do it for my current directory). I tried ...
163
votes
5answers
250k views

Easiest way to copy ssh keys to another machine?

I am lazy at home and use password authentication for my home machines. I am ready to move to key based authentication. There are many options on the web on how to do this, including catting then ...
163
votes
11answers
383k views

How to install OpenJDK 8 on 14.04 LTS?

As of 2016-04-23 Ubuntu 16.04 has ben released, with both OpenJDK 8 and 9 in the official repositories. I would recommend upgrading to that. As of 2016-01-11 OpenJDK 8 is still not available in an ...
162
votes
12answers
185k views

Progress and speed with 'cp'?

When copying files using cp, is it possible to display the progress and speed of the transfer? Otherwise, is there any alternative command line utility that can achieve this?
162
votes
12answers
163k views

How do I reset my Unity configuration?

I've been messing around with Unity and broke something, how do I "start over"?
162
votes
6answers
158k views

How do I remap certain keys or devices?

I'm searching for a way to remap certain keys in ubuntu. i.e. I'd like to change PgUp to Home or PgDown to End. Does a built-in command or a tool exist reassign keys in Ubuntu/GNOME?
161
votes
9answers
312k views

How do I increase the hard disk size of the virtual machine?

I have run out of space on my WinXP virtual machine, which I only gave 10 GB space for when I created it. Is there an easy way to increase it to, say, 20 GB? I can't see any obvious option in ...
159
votes
8answers
285k views

How do I create a permanent Bash alias?

I would like to create an alias to rm command in order to have a confirmation message after executing this command. So I am creating an alias like this alias rm='rm -i'. But as far as I know this is a ...
159
votes
2answers
179k views

How to enable TRIM?

I know that the Linux kernel supports TRIM as of version 2.6.33, so there should be TRIM support in ubuntu. Is TRIM enabled by default or do I need to change some settings or install additional ...
158
votes
6answers
237k views

Why does a Ubuntu guest in VirtualBox run very, very slowly?

I'm using currently Ubuntu 12.04 LTS as a host machine, and I've virtualized three machines: a Xubuntu 12.04 guest a Windows 7 guest a Ubuntu 12.10 guest All the guests have the same VirtualBox ...
157
votes
10answers
203k views

How do I fix the GPG error “NO_PUBKEY”?

I added some extra repositories with the Software Sources program. But when I reload the package database, I get an error like the following: W: GPG error: http://ppa.launchpad.net trusty ...
157
votes
15answers
385k views

How to install Eclipse?

I want to install the latest version of Eclipse but the Ubuntu Software Centre contains an older version. Is there a PPA or some other way to install latest Eclipse? Please describe the steps for ...
157
votes
14answers
228k views

What are some GUI clients for Git?

I am using git for version control of various projects. Is there easy-to-use software for navigating through commits and branches of a project and for retrieving versions?
156
votes
6answers
1.2m views

How to install Google Chrome?

How do you install Google Chrome on Ubuntu?
156
votes
5answers
363k views

How do I install curl in php5?

I currently have PHP 5.3 installed with Apache in 10.04 Lucid. How can I add the PHP Curl libraries? Do I need to install any other dependencies for curl?
156
votes
5answers
193k views

How to Downgrade a Package via apt-get?

How to downgrade a package to an older version via apt-get?! Another tools are also accepted but apt-get is preferred.
156
votes
14answers
338k views

How can you log out via the terminal?

Is there a command, that will take you back to the login screen?
154
votes
5answers
244k views

How can I fix a 404 Error when using a PPA or updating my package lists?

PPA seems to be constantly offline. Whenever I use sudo apt-get update, this error is shown: W: Failed to fetch http://ppa.launchpad.net/ 404 Not Found How do I fix these errors?
153
votes
5answers
234k views

Why use apt-get upgrade instead of apt-get dist-upgrade?

I usually use apt-get update && apt-get upgrade to run my updates and upgrades instead of the GUI because it seems to run more quickly. However, I've noticed lately that I often get a ...

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