Ubuntu is a Linux distribution with an emphasis on ease of use and installation. Note that http://askubuntu.com is specifically dedicated to Ubuntu questions.

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What happens in each step of the Linux kernel-building process?

I've read many tutorials about how to build custom kernels and boot Ubuntu using those kernels, and successfully followed the guides and booted custom kernels, but I have no understanding about what ...
17
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4answers
10k views

bulk rename (or correctly display) files with special characters

I have a bunch of directories and subdirectories that contain files with special characters, like this file: robbie@phil:~$ ls test�sktest.txt test?sktest.txt Find reveals an escape sequence: ...
17
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3answers
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Are multiple @daily crontab entries processed in order, serially?

I want two jobs to run sometime every day, serially, in exactly the order I specify. Will this crontab reliably do what I want? @daily job1 @daily job2 I'm assuming they run one after the other, ...
16
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4answers
13k views

Mount a filesystem read-only, and redirect writes to RAM?

Is it possible to mount a loopback file as read-only, and redirect all writes to RAM?
16
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2answers
6k views

Why is vi apparently broken (viminfo error E576), and how can I fix it?

I am proficient at using Unix/Linux, but I am not an expert. If I want to open a file (for example, file.txt), I use vi: vi file.txt This opens the file, and if I want to close it, I use :q!. I ...
16
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1answer
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What does a kernel source tree contain? Is this related to Linux kernel headers?

In books, I typically read references to the Linux Source Tree at /usr/src/linux with the usual set of subdirectories (arch, block, crypto, ...). I was expecting this tree to contain the binary files ...
16
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1answer
13k views

How do I set a user's default .bashrc file?

On Ubuntu 10.4 I have edited the /etc/bash.bashrc file to set some variables like the command history size (HISTSIZE=5000), however if I create a new users Ubuntu by default gives them a .bashrc file ...
16
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2answers
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Vulnerability demonstration on Ubuntu 9.04

For a class on IT security, I want to demonstrate privilege escalation to the students. To do so, I looked through the exploit/linux/local list in the Metasploit Framework, finding (among others) ...
16
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2answers
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What is the “/usr/local/src” folder meant for?

I wanted to put my work files (code) in /usr/local/src, but I think it's already a folder that has some other semantic meaning. What is that? Should I put source code there, or is there a better ...
15
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2answers
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Recovering from 'grub rescue>' crash [closed]

Originally posted to AskUbuntu.com ... AskUbuntu has adopted a policy of closing questions about EOL (End Of Life) versions. There's a vocal contingent to remove them as well. To prevent ...
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5answers
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How is sudo set to not change $HOME in Ubuntu and how to disable this behavior?

On Ubuntu 12.04, when I sudo -s the $HOME variable is not changed, so if my regular user is regularuser, the situation goes like this: $ cd $ pwd /home/regularuser $ sudo -s # cd # pwd /home/...
15
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1answer
20k views

Hide curl output

I'm making a curl request where it displays an html output in the console like this <b>Warning</b>: Cannot modify header information - headers already sent by (output started at /home/...
15
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3answers
20k views

Linux, disable /dev/fd0 (floppy)

Is it possible to make Linux kernel completely ignore the floppy disk controller? I do not have the drive but obviously my motherboard does contain the controller. I would like to disable the /dev/fd0 ...
15
votes
2answers
112k views

How to recover files I deleted now by running rm *? [duplicate]

By mistake I ran rm * on the current directory where I created many c program files. I had been working on these since morning. Now I can't take out again the time that I spent since morning on ...
15
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3answers
26k views

How to configure external IP addresses for LXC guests?

I'm exploring the LXC features in Ubuntu 12.04 and I really want to set up a network like this: client1: 192.168.56.101/24 lxc-host: 192.168.56.102/24 guest1 192.168.56.201/24 guest2 192....
15
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3answers
23k views

How to boot EFI kernel using QEMU (kvm)?

Hey guys I'm trying to emulate a EFI enviroment using QEMU (kmv), virtualbox takes 15 minutes to boot in EFI mode using archboot. Using legacy BIOS mode I can boot using this command: root@...
15
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5answers
21k views

Why doesn't docker container start at boot w/ upstart script on Ubuntu 12.04?

Using instructions for Docker auto-start on Linode VPS running Ubuntu 12.04 and Docker 0.8.1, the specified container does not start on reboot. Once booted, I am able to ~$ sudo start [service-name] ...
14
votes
4answers
3k views

Is there a way to auto turn-on Ubuntu?

Like a command line or a small piece of software I know that there are many ways to auto-shutdown, but I'm concerned about auto-turn-on.
14
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3answers
2k views

How can I de-fragment a drive using Ubuntu?

Is it necessary to defrag drives in Ubuntu? If so, how do I do it and how often should it be done?
14
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4answers
527 views

What specific vulnerabilities am I creating by disabling the sudo password?

Here are some instructions on how to disable your sudo password. These carry the following warning If you disable the sudo password for your account, you will seriously compromise the security of ...
14
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3answers
9k views

l, ls & la — what are the differences, and are there more of these commands?

So, through typing several commands I've found that there's not only ls, but l and la too. There doesn't appear to be any man entries on Ubuntu 12.14. They all appear to do similar things with minor ...
14
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7answers
3k views

Can I label a disk device rather than a partition?

I know about the e2label and friends program for attaching a label to a disk partition e.g. e2label /dev/sda1 bla What I want to do is something different: I want to create a label for a hard drive,...
14
votes
3answers
13k views

What is the proper way to manage multiple python versions?

I have a machine with Python 2.6 installed as the default Python. Then, I installed Python 2.7, and manually created /usr/bin/python as a symlink to the new installation. Then, I was running into ...
14
votes
1answer
27k views

How to permanently disable a network interface?

I've brought down a network interface with ifconfig wlan0 down, but every few hours or so, the wlan0 interface comes back up and I can't figure out why. I don't restart the machine, never changed /...
14
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3answers
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How can I track who SSH'es into my linux machine?

I'm running Ubuntu 10.04. Is there a way I can get a daily report of who has logged onto the box, what time, and even - this may be asking too much - a report of the commands they used? This is a low-...
14
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1answer
6k views

Installing two glibc alongside in debian/ubuntu

Is it possible to install and use two different glibc versions on the same machine. Where one version is only used to run legacy software, which relies on old glibc binaries? Is it possible to do ...
13
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6answers
2k views

Is there a root password on OS X and Ubuntu?

When you setup a new Ubuntu or OS X installation a user is generally created for you. On OS X it is whatever username you pick. On Ubuntu (the server version) usually the ubuntu user is created. The ...
13
votes
7answers
17k views

Linux equivalent for Windows Startup

Is there any way to add an application/script to the Linux startup so every time the system is on it executes [i'm looking for some automated way, user should not add this by cron job or something ...
13
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4answers
9k views

/etc/rc.d vs /etc/init.d

Is ubuntu's /etc/init.d directory exactly equivalent (functionally) to what I presume to be the more standard /etc/rc.d/ (at least on arch)? Is there any particular reason canonical used init.d ...
13
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4answers
755 views

Monitor hard disk activity

In a Ubuntu 14.04 server I am experiencing a massive hard disk activity which has no apparent justification: it comes as a burst, it lasts a few minutes and then disappears. It consumes system ...
13
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2answers
9k views

Installing mysql-server in vagrant bootstrap shell script (how to skip setup?)

I did try to install mysql-server on my Vagrant Ubuntu 12.04 LTS virtual machine. When I did so, the setup auto-starts. I can see this in the Vagrant output: While not mandatory, it is highly ...
13
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4answers
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How to find out if Ubuntu is using DHCP (Ubuntu 12.04 LTS GUI)

How can I find out if my IP address is DHCP, Fixed or Dynamic? I need to tell my network administrator what the IP address is, that my Virtual Machine is using. I know the numbers, but I don't know ...
13
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4answers
2k views

In Debian based systems, how do we purge configuration files of packages that have already been uninstalled?

To be more specific, I would like to do the equivalent of adding the --purge flag to the following command sudo apt-get autoremove --purge [package name] to packages that are no longer on the ...
13
votes
4answers
7k views

How to /dev/null background processes “informational” output?

[USER@SERVER ~] sleep 3 & [1] 5232 [USER@SERVER ~] [1]+ Done sleep 3 [USER@SERVER ~] How do I /dev/null these two messages?: [1] 5232 [1]+ Done sleep ...
13
votes
1answer
4k views

Using Atlas from scipy

I installed Ubuntu 12.04 64 bit. I need to work with python and scipy, I installed them and when I run the test: python -c "import scipy; scipy.test()" I get the message: ImportError: libatlas....
13
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4answers
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XFS vs Ext4 vs Others - which file system is stable, reliable, for long run such as 24/7 case [closed]

XFS and Ext4 file system which one is really stable and reliable for long run with heavy disk write and read? the system will be used in a place where 24/7 is in service, and every second there is ...
13
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4answers
13k views

I changed my hostname, why is my bash PS1 prompt unchanged

I changed my hostname by editing /etc/hostname and can see the new hostname using the hostname and hostname -F commands. But the shell prompt is still showing the old hostname. This is Ubuntu 11.0.4 ...
13
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4answers
11k views

How to get rid of the “scanning for btrfs file systems” at start-up?

After upgrading from Ubuntu 12.04 to Ubuntu 12.10, I get a message "scanning for btrfs file systems" at starting-up. I don't have any BTRFS filesystem. It delays the booting for about 15 seconds. How ...
13
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2answers
2k views

Is it possible to simulate installation of Debian packages, still marking them installed?

Here's what I would like. Start with a virtual system with no installed packages. Then I invoke a tool similar to apt-get to ask it to compute the dependencies and mark all the packages that would be ...
12
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2answers
45k views

Where does postfix store email?

I can't find any documentation on how postfix stores email. Where is it stored, and in what format? I'm using Ubuntu server 11
12
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5answers
23k views

Can't apply chmod to a file

I have a file on my HDD, cd /media/celebisait/5AC69788C6976355 There is my file called myFile.tar.gz. I do als -l, -rw------- 2 celebisait celebisait 1387745311 Jun 6 2013 myFile.tar.gz ...
12
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6answers
33k views

Where is Netbeans installed on Ubuntu?

I installed Netbeans on my Ubuntu 11.10 machine. I used the combined method, so Netbeans and JDK are installed from a single file. However, now that it's installed I can't figure out how to start ...
12
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5answers
682 views

Is there a more succinct alternative to piping to wc for counting files in a directory

If I do ls -1 target_dir | wc -l, I get a count of files in a directory. I find this a bit cumbersome. Is there a more elegant or succinct way?
12
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5answers
27k views

Can a linux user change their password without knowing the current password?

I'm setting up a few ubuntu boxes, and using opscode's chef as a configuration tool. It would be fairly easy to install public keys for each user on each of these servers, and disable password ...
12
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2answers
3k views

How to implement package install suggestion on Debian?

I have noticed that while on Ubuntu, if I type the following: mc and it isnt installed, I get the message below: The program 'mc' is currently not installed. You can install it by typing: sudo apt-...
12
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3answers
6k views

Why don't my arrow keys work in sh?

I recently installed Ubuntu and when I run sh on the Terminal my arrow keys don't work so I can't go through my call history or edit whatever I'm typing. It just comes out as weird characters like ^[[...
12
votes
1answer
355 views

Partitioning done incorrectly?

Long story short, we had issues installing linux on this system. It magically decided to work, but now I'm unsure about the hard drive partitioning. One hard drive has linux installed on it and the ...
12
votes
6answers
8k views

Screen turns on automatically (xset dpms force off)

I am using xset dpms force off to manually turn my screen off to save power. However, it turns back on after some time (20 - 40 seconds). Distro: Ubuntu-Lucid Graphics: Intel 4500 MHD ...
12
votes
1answer
5k views

How can I monitor CPU usage by user?

I need to monitor CPU usage by users of two servers' (Ubuntu and CentOS). For example: user1 5% user2 10% ... Is there a tool similar to top or htop that can do that?
12
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2answers
18k views

How can I make this daemon/init run as a non root user?

I have an init script to kick off a daemon. The problem is it runs as root. I would like it to run as a user called "deploy". Ubuntu 12.04 #! /bin/sh # File: /etc/init.d/unicorn ### BEGIN INIT ...