Ubuntu is a free open source operating system based on the Debian GNU/Linux distribution. Consider using http://askubuntu.com/ to ask questions about it.

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34
votes
8answers
7k views

How do you track which packages were installed on Ubuntu (Linux)?

(This question is very similar to 10458. It was suggested that Fedora and Ubuntu/Debian are different enough to warrant different answers.) As I use any Ubuntu setup I gradually install a number of ...
33
votes
3answers
16k views

Convert a PDF to greyscale on the command line in FLOSS?

I have a colour PDF file, and I'm going to print it out and then photocopy it in black and white. I'd like to know what it's like in B&W before photocopying it. Is it possible to 'greyscale' a PDF ...
33
votes
3answers
91k views

How does one change user's home directory in Ubuntu 9.04?

Does anyone know how I might change my home directory in the shell please?
33
votes
9answers
17k views

Clipboard manager for Ubuntu?

I'm looking for a good program for managing clipboard history on the Ubuntu desktop used primaraly for software development. Ditto is exactly what I need, except it wont run on Ubuntu.
33
votes
4answers
90k views

How to update Google chrome in Ubuntu?

How to update Google chrome in Ubuntu?
32
votes
7answers
54k views

tar: Exiting with failure status due to previous errors

I have written a little script that tars and compresses a list of directories + files. The script appears to run succesfully, in that a useable .tar.gz file is created after the script runs. ...
32
votes
3answers
67k views

How can I update gcc to the latest version in Ubuntu 10.04?

I have Ubuntu 10.04 32-bit with gcc 4.4.3 currently installed on it. I want to upgrade it to gcc 4.6.1. How to update using Ubuntu Package Manager: apt-get upgrade/install As a second option I ...
32
votes
3answers
13k views

Bad font anti-aliasing in Ubuntu

I'm switching from Fedora 8 to Ubuntu 9.04, and I can't seem to get it to get a good font anti-aliasing to work. It seems that Ubuntu's fontconfig tries to keep characters in integral pixel widths. ...
31
votes
2answers
25k views

Are there any real advantages to assigning more “cores” to VirtualBox?

I have an 2.8 quad core i7 with a VirtualBox. I have the option of assigning up to 4 cores to a guest machine, but I have only been doing two. What are the advantages/disadvantages of assigning more ...
31
votes
3answers
33k views

Disable MySQL startup in Ubuntu 10.04

I want to prevent MySQL from starting in Ubuntu 10.04 I have used update-rc.d -f mysql remove and confirmed that there is no link to the /etc/inid.d/mysql script from any of the rc?.d directories. ...
30
votes
8answers
13k views

Swap partition size on a 64 GB RAM computer for memory-intensive work

I have 64 GB RAM and 240 GB SSD on my computer, which I'm going to use for memory-intensive calculations (machine learning, data mining, etc.). Most of the advice I found on the Internet are ...
30
votes
7answers
5k views

Is it possible to “virtualize” an existing PC?

I'm running Ubuntu Desktop 12.04, and I was wondering if it was possible to somehow take my whole filesystem (everything under /) and create an ISO from it. Then, perhaps, use that ISO as the file ...
30
votes
2answers
5k views

on ubuntu 13.10 multiple hits on ctrl+tab makes my intellij 13 keyboard stuck (no key works)

I have to restart my intellij every like 20 minutes whenever I hit multiple times ctrl+tab. It looks like clicking this multiple time on my ubuntu 13.10 + intellij 13.01 makes my intellij stuck. on ...
30
votes
10answers
39k views

How to extract text with OCR from a PDF on Linux?

How do I extract text from a PDF that wasn't built with an index? It's all text, but I can't search or select anything. I'm running Kubuntu, and Okular doesn't have this feature.
30
votes
3answers
80k views

How do I log out of `sudo su`?

I'm using sudo su to start mysql and do some homework with it. When I finish with mysql (or any other command), then I'm still in sudo. How do I "log out", so my prompt changes back from # to $?
30
votes
8answers
14k views

Find all user-installed packages

Is there any way to get a list of all user-installed packages on an Ubuntu system, i.e. the packages that were installed on top of the default installed packages? (The idea is to get a comprehensive ...
29
votes
3answers
58k views

How to run a cron job as a specific user?

I would like to run a cron job as a specific user on my machine. How may I specify the user for a cron job to run as?. I am running on Ubuntu 10.0.4 [Edit] The cron jobs will be running on a ...
29
votes
5answers
30k views

How do I stop services from starting on boot on Ubuntu?

I have lots of servers installed (Apache, MySQL, etc.), but I don't want them all to start at boot time (they drain power, and I'm on batteries most of the time). How do I configure this?
29
votes
4answers
72k views

How do you add a certificate authority (CA) to Ubuntu?

My work has decided to issue their own certificate authority (CA) to handle different aspects of our work securely without paying for certificates. Cryptographically sign emails Encrypt email ...
29
votes
6answers
37k views

How can I view results of my cron jobs?

I see so many guides on how to run crontab, but what I need right now is to learn how to Find log files about cron jobs Configure what gets logged
29
votes
12answers
37k views

Enable system beep in Ubuntu

I have tried to get the system beep working, but with no success. I used echo -e '\a' and the beep application. I have tried entering modprobe pcspkr at the command line, and made sure pcspkr is not ...
28
votes
6answers
61k views

play mp3 or wav file via Linux command line

I would like to make an alarm system backed by a Ubuntu (no graphical interface) box, which plays various announcement and alarm audio tracks (.mp3 or .wav) via the command line. For example: $ ...
28
votes
5answers
93k views

How can I add a regular user to the sudoers file?

How can I add more users to the "sudoers" file?
28
votes
2answers
54k views

Where can I get the repositories for old Ubuntu versions?

Where can I get the old repositories for Ubuntu versions? In my case, it's 9.04 Jaunty? I found all the official repositories and their mirrors have been removed. I am wondering where I can get the ...
28
votes
2answers
21k views

How can I check the version of packages to be installed with apt-get?

After running apt-get upgrade, I get a list of the packages that will be upgraded. I would like to know the version number for one of these packages. (Not the current one but the one that will be ...
27
votes
7answers
50k views

'No such file or directory' error in bash, but the file exists?

On Ubuntu, I get a 'No such file or directory' error when I try to execute a command. I have checked with ls -la , the file adb is there and it has 'x' flag So why I am getting a 'No such file or ...
27
votes
4answers
2k views

How to create a file which is named like a command line argument?

I was wondering how to make a file named as a flag, e.g., if I wanted to make a folder named -a, what commands would do the trick? I tried mkdir '-a', mkdir \-a, and neither worked. I'm on Ubuntu.
27
votes
9answers
22k views

Remote desktop to Mac from various platforms (Windows, Ubuntu)

I fear I know the answer to this already, but I would like to be able to connect to my Mac Mini in a 'remote desktop' fashion. I would like to connect to my Mac as if I were sat at my desk, but I ...
26
votes
2answers
4k views

Why is it so hard to find a file in Ubuntu?

It's very hard to find files in Ubuntu. In Windows, you could just go to C:\Program Files and you would find what you need. In Ubuntu, you must use search to find something you need. Maybe I am ...
26
votes
4answers
6k views

How do you run the previous command in emacs shell?

I am in terminal mode on Ubuntu, and I'm running emacs with 2 buffers open, one is a ruby file, and the other is a shell (opened by typing M-x shell ), and when I switch to the shell buffer, I want to ...
26
votes
7answers
5k views

Why create many partitions?

I have noticed that when installing Ubuntu some people create multiple partitions for directories. Like one for root, one for home, one for boot. What is the advantage to doing this over installing ...
26
votes
6answers
65k views

How do you disable an upstart service in ubuntu 10.10?

In 10.10 upstart is being used instead of sysvinit. It's possible to remove annoying upstart services which you do not want by removing the appropriate file in /etc/init/blah.conf However, this ...
25
votes
4answers
35k views

How do I find (and kill) process running on a certain port? [duplicate]

Possible Duplicate: Finding the process that is using a certain port in Linux I'm using Ubuntu Linux 11.04. How do I write a shell script expression that will find the process running on ...
25
votes
2answers
50k views

What does /dev/sda for linux mean?

What does : /dev/sda stand for? What does it mean? I have both Fedora and Ubuntu installed and if I explore them using Ext2explore from windows, I see these names : /dev/sda6 /dev/sda9 Please ...
25
votes
2answers
25k views

Is it possible to install the Helvetica font on linux?

I don't know too much about the licensing issues surrounding fonts, but I would like to install Helvetica on my machine for my own personal use. I haven't been able to find a whole lot about this on ...
25
votes
1answer
15k views

sh: make: not found

I got the following error message: sh: make: not found I guess I need to install make, or a compiler on my Ubuntu 9.04 Could you tell me what I exactly need to type to install it?
25
votes
4answers
39k views

How do I install Maven 3?

I am using Ubuntu and need to upgrade to Maven 3 from Maven 2. Can someone please help me install Maven 3?
25
votes
5answers
51k views

How can I make mdadm auto-assemble RAID after each boot?

I successfully created a RAID (mirroring) by utilizing mdadm. However, I must run the following commands after each boot: mdadm --stop --scan // to stop /dev/md127 - I don't know where the number 127 ...
24
votes
5answers
26k views

How Do I Find The Hardware Block Read Size for My Hard Drive?

I'm trying to figure out the optimal size for a large copy from my hard drive using dd. I'm trying to figure out what the best blocksize to use it, which I would assume is the hardware block size for ...
24
votes
9answers
6k views

How to track LAN usage? (AKA 'top for LAN')

There's an evil application that is eating ALL my upload bandwidth (I'm brazilian, it's only ~35kbps) for like 80% of the time my PC is turned on. I would like to know if there's any way to track ...
24
votes
2answers
14k views

How can I get virtualbox to run with a hosts-only adapter?

I'm trying to setup a Hosts-only Adapter so I can connect to it. It says that invalid settings detected and the name: drop-down isn't populated. What am I doing wrong and how can I rectify it? My ...
24
votes
8answers
13k views

Linux keylogger without root or sudo! Is it real?

Somebody on Youtube claims to have a keylogger on Ubuntu that was neither executed nor installed as root. The link below shows a demo of it working. http://www.youtube.com/watch?v=Y1fZAZTwyPQ ...
24
votes
4answers
14k views

How do I “identify with services” on IRC?

I am using irrsi as my irc cilent on ubuntu I have entered "/join #android-dev" in my command window. But I am getting this error message: 22:05 -!- #android-dev Cannot join channel (+r) - you need ...
24
votes
6answers
64k views

Why do I need to enter a password for the Default Keyring to unlock?

When I log into Ubuntu, I am prompted every time to: Enter Password for Default Keyring to Unlock I want to avoid this step since I am the only person using this machine and I see no reason to have ...
23
votes
9answers
51k views

Mouse clicks suddenly stopped working in Ubuntu

This is a weird one. For some reason, last night my mouse partially stopped working. Movement is fine, but the mouse buttons don't work. Mainly it's the left button, but occasionally the right click ...
23
votes
3answers
7k views

How do you find the Ubuntu version (release number / name) from the command line?

How do you find the Ubuntu version (release number / name) from the command line?
23
votes
5answers
17k views

How can I open a .7z file in Ubuntu?

How can I open a .7z file in Ubuntu?
23
votes
5answers
25k views

Synergy Key Mapping

I'm running a Synergy server on Ubuntu and a Synergy+ client on OSX. The server has a standard windows keyboard with shift, ctrl, windows, and alt keys. My MacBookPro has shift, fn, control, ...
23
votes
5answers
65k views

How can I edit the $PATH on linux?

I am using ubuntu 9.04 I need to add some folder to my $PATH. I know how to read the path: echo $PATH I want to be able to edit it and add 2 other paths. Thanks
23
votes
5answers
12k views

What is the difference between Debian and Ubuntu?

From what I heard Ubuntu is a basically a Debian Linux with some extra applications and drivers pre-installed in order to make it more user friendly. Is that all? Or are there deeper, more ...