ubuntu interview questions
Top ubuntu frequently asked interview questions
I was trying to install rails on Ubuntu Natty Narwhal 11.04, using ruby1.9.1.
I installed ruby using apt-get install ruby1.9.1-full which contains the dev package. I googled the error and all have suggested I install the 1.9.1-dev which I already have.
Building native extensions. This could take a while...
ERROR: Error installing rails:
ERROR: Failed to build gem native extension.
/usr/bin/ruby1.8 extconf.rb
extconf.rb:36:in `require': no such file to load -- mkmf (LoadError)
from extconf.rb:36
Gem files will remain installed in /usr/lib/ruby/gems/1.8/gems/bcrypt-ruby-3.0.1 for inspection.
Results logged to /usr/lib/ruby/gems/1.8/gems/bcrypt-ruby-3.0.1/ext/mri/gem_make.out
Source: (StackOverflow)
I'm working on Ubuntu and want to use multiple private keys to connect to different servers or different portions of the same server (My uses are admin of server, admin of git, and normal git usage within the same server). I tried simply stacking the keys in the id_rsa files to no avail.
Apparently the way to do this is use the command ssh -i <key location> login@server.com. That is quite cumbersome.
Any suggestions as to how to go about doing this a bit easier?
Source: (StackOverflow)
I recently saw that the Git console in Windows is colored, e.g. Green for additions, red for deletions, etc. How do I color my Ubuntu Git console like that?
To install it, I used the command: $ apt-get install git-core
Source: (StackOverflow)
I am new to Apache and I wanted to ask, where is my httpd.conf file located? I am running a server from the amazon ec2 (elastic compute cloud) and I can't find my apache config. Can someone please tell me where it is located? Thanks!
Source: (StackOverflow)
After upgrading to Ubuntu 13.10, when I click on any menus in Eclipse (Help, Window, Run) they don’t show up. Only menu stubs and selection are visible.
I tried installing fresh 4.3 and the same thing is happening. Is anyone else experiencing this behavior?
Source: (StackOverflow)
I'm having difficulty installing lxml with easy_install on Ubuntu 11.
When I type $ easy_install lxml I get:
Searching for lxml
Reading http://pypi.python.org/simple/lxml/
Reading http://codespeak.net/lxml
Best match: lxml 2.3
Downloading http://lxml.de/files/lxml-2.3.tgz
Processing lxml-2.3.tgz
Running lxml-2.3/setup.py -q bdist_egg --dist-dir /tmp/easy_install-7UdQOZ/lxml-2.3/egg-dist-tmp-GacQGy
Building lxml version 2.3.
Building without Cython.
ERROR: /bin/sh: xslt-config: not found
** make sure the development packages of libxml2 and libxslt are installed **
Using build configuration of libxslt
In file included from src/lxml/lxml.etree.c:227:0:
src/lxml/etree_defs.h:9:31: fatal error: libxml/xmlversion.h: No such file or directory
compilation terminated.
It seems that libxslt or libxml2 is not installed. I've tried following the instructions at http://www.techsww.com/tutorials/libraries/libxslt/installation/installing_libxslt_on_ubuntu_linux.php and http://www.techsww.com/tutorials/libraries/libxml/installation/installing_libxml_on_ubuntu_linux.php with no success.
If I try wget ftp://xmlsoft.org/libxml2/libxml2-sources-2.6.27.tar.gz I get
<successful connection info>
==> SYST ... done. ==> PWD ... done.
==> TYPE I ... done. ==> CWD (1) /libxml2 ... done.
==> SIZE libxml2-sources-2.6.27.tar.gz ... done.
==> PASV ... done. ==> RETR libxml2-sources-2.6.27.tar.gz ...
No such file `libxml2-sources-2.6.27.tar.gz'.
If I try the other first, I'll get to ./configure --prefix=/usr/local/libxslt --with-libxml-prefix=/usr/local/libxml2 and that will fail eventually with:
checking for libxml libraries >= 2.6.27... configure: error: Could not find libxml2 anywhere, check ftp://xmlsoft.org/.
I've tried both versions 2.6.27 and 2.6.29 of libxml2 with no difference.
Leaving no stone unturned, I have successfully done sudo apt-get install libxml2-dev, but this changes nothing.
Source: (StackOverflow)
I am using nginx on Rackspace cloud following a tutorial, searched the net and so far can't get this sorted.
I want www.mysite.com to go to mysite.com as normal in .htaccess for seo and other reasons.
My vi /etc/nginx/sites-available/www.example.com.vhost code:
server {
listen 80;
server_name www.example.com example.com;
root /var/www/www.example.com/web;
if ($http_host != "www.example.com") {
rewrite ^ http://example.com$request_uri permanent;
}
I have also tried
server {
listen 80;
server_name example.com;
root /var/www/www.example.com/web;
if ($http_host != "www.example.com") {
rewrite ^ http://example.com$request_uri permanent;
}
I also tried. Both the second attempts give redirect loop errors.
if ($host = 'www.example.com' ) {
rewrite ^ http://example.com$uri permanent;
}
My DNS is setup as standard:
site.com 192.192.6.8 A type at 300 seconds
www.site.com 192.192.6.8 A type at 300 seconds
(example IPs and folders have been used for examples and to help people in future). I use Ubuntu 11.
Source: (StackOverflow)
NodeJS interpreter name(node) on Ubuntu has been renamed to nodejs because of name conflict with another package. Here's what the readme.debian says:
The upstream name for the Node.js interpreter command is "node".
In Debian the interpreter command has been changed to "nodejs".
This was done to prevent a namespace collision: other commands use
the same name in their upstreams, such as ax25-node from the "node"
package.
Scripts calling Node.js as a shell command must be changed to instead
use the "nodejs" command.
However, using nodejs mucks up installing packages using npm. Package installation fails with the following error:
sh: 1: node: not found
npm WARN This failure might be due to the use of legacy binary "node"
npm WARN For further explanations, please read /usr/share/doc/nodejs/README.Debian
How do I make npm understand that nodejs is already installed on the system but the interpreter name is different?
Source: (StackOverflow)
Every time I try to open Eclipse in Ubuntu 12.04 I get an Unsatisfied Link Error and it will not open. I have recently installed the java JDK and Android SDK, could this be the problem? I followed this tutorial.
Here is the log info:
!SESSION 2012-04-15 21:05:46.902 -----------------------------------------------
eclipse.buildId=I20110613-1736
java.version=1.7.0
java.vendor=Oracle Corporation
BootLoader constants: OS=linux, ARCH=x86_64, WS=gtk, NL=en_GB
Command-line arguments: -os linux -ws gtk -arch x86_64
!ENTRY org.eclipse.osgi 4 0 2012-04-15 21:05:47.885
!MESSAGE Application error
!STACK 1
java.lang.UnsatisfiedLinkError: Could not load SWT library. Reasons:
no swt-gtk-3740 in java.library.path
no swt-gtk in java.library.path
Can't load library: /home/tom/.swt/lib/linux/x86_64/libswt-gtk-3740.so
Can't load library: /home/tom/.swt/lib/linux/x86_64/libswt-gtk.so
at org.eclipse.swt.internal.Library.loadLibrary(Library.java:285)
at org.eclipse.swt.internal.Library.loadLibrary(Library.java:194)
at org.eclipse.swt.internal.C.<clinit>(C.java:21)
at org.eclipse.swt.internal.Converter.wcsToMbcs(Converter.java:63)
at org.eclipse.swt.internal.Converter.wcsToMbcs(Converter.java:54)
at org.eclipse.swt.widgets.Display.<clinit>(Display.java:132)
at org.eclipse.ui.internal.Workbench.createDisplay(Workbench.java:695)
at org.eclipse.ui.PlatformUI.createDisplay(PlatformUI.java:161)
at org.eclipse.ui.internal.ide.application.IDEApplication.createDisplay(IDEApplication.java:153)
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:95)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:344)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:179)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:622)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:577)
at org.eclipse.equinox.launcher.Main.run(Main.java:1410)
at org.eclipse.equinox.launcher.Main.main(Main.java:1386)
I have tried uninstalling and reinstalling, and removing the ~/.eclipse directory but it still doesn't work
Source: (StackOverflow)
This is the PATH variable without sudo:
$ echo 'echo $PATH' | sh
/opt/local/ruby/bin:/usr/bin:/bin
This is the PATH variable with sudo:
$ echo 'echo $PATH' | sudo sh
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/X11R6/bin
As far as I can tell, sudo is supposed to leave PATH untouched. What's going on? How do I change this? (This is on Ubuntu 8.04).
UPDATE: as far as I can see, none of the scripts started as root change PATH in any way.
From man sudo:
To prevent command spoofing, sudo
checks ``.'' and ``'' (both denoting
current directory) last when searching
for a command in the user's PATH (if
one or both are in the PATH). Note,
however, that the actual PATH
environment variable is not modified
and is passed unchanged to the program
that sudo executes.
Source: (StackOverflow)
I have the following error during sqlite3-ruby install:
Building native extensions. This could take a while...
ERROR: Error installing sqlite3-ruby:
ERROR: Failed to build gem native extension.
/usr/bin/ruby1.8 extconf.rb
checking for sqlite3.h... no
sqlite3.h is missing. Try 'port install sqlite3 +universal' or 'yum install sqlite3-devel'
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of
necessary libraries and/or headers. Check the mkmf.log file for more
details. You may need configuration options.
Provided configuration options:
--with-opt-dir
--without-opt-dir
--with-opt-include
--without-opt-include=${opt-dir}/include
--with-opt-lib
--without-opt-lib=${opt-dir}/lib
--with-make-prog
--without-make-prog
--srcdir=.
--curdir
--ruby=/usr/bin/ruby1.8
--with-sqlite3-dir
--without-sqlite3-dir
--with-sqlite3-include
--without-sqlite3-include=${sqlite3-dir}/include
--with-sqlite3-lib
--without-sqlite3-lib=${sqlite3-dir}/lib
Gem files will remain installed in /usr/lib/ruby/gems/1.8/gems/sqlite3-ruby-1.3.1 for inspection.
Results logged to /usr/lib/ruby/gems/1.8/gems/sqlite3-ruby-1.3.1/ext/sqlite3/gem_make.out
sqlite3.h is located in /usr/include/
sudo gem install sqlite3-ruby --without-sqlite3-include=/usr/include
doesn't work
ERROR: While executing gem ... (OptionParser::InvalidOption)
invalid option: --without-sqlite3-include=/usr/include
Ubuntu 10.04
Source: (StackOverflow)
I have a private key protected with a password to access a server via SSH.
I have 2 linux (ubuntu 10.04) machines and the behavior of ssh-add command is different in both of them.
In one machine, once I use "ssh-add .ssh/identity" and entered my password, the key was added permanently, i.e., every time I shutdown the computer and login again, the key is already added.
In the other one, I have to add the key every time I login.
As far as I remember, I did the same thing on both. The only difference is that the key was created on the one that is added permanently.
Does anyone know how to add it permanently to the other machine as well?
Source: (StackOverflow)
I have two files, file1 and file2. How do I append the contents of file2 to file1, without overwriting the current file1. How do I do this on Ubuntu Linux?
Source: (StackOverflow)
I have both python2.7 and python3.2 installed in Ubuntu 12.04.
The symbolic link python links to python2.7.
When I type:
sudo pip install package-name
It will default install python2 version of package-name.
Some package supports both python2 and python3.
How to install python3 version of package-name via pip?
Source: (StackOverflow)