Entries Tagged 'Linux' ↓

Hi! If you're new here, you may want to subscribe to the Unix Tutorial RSS feed to get regular tips & tricks for all flavors of Unix. Thanks for visiting!

Mounting an ISO image of a CD/DVD before burning it is one of the basic steps to verifying you're going to get exactly the desired result. It's also a neat trick to access files from a CD/DVD image when you only need a file or two and not a whole CD. Why burn it at all when you can access files much quicker and easier by simply mounting the ISO image?

Every Unix OS has a way to access ISO filesystem, and today I'll only give you examples for Linux and Solaris. In both cases, the two things you need for the example to work are the ISO image itself and an available mount point (basically, an empty directory) on your filesystem to mount it under.

Here's how to mount an ISO in Linux:

# mount -o loop /net/server/linux-bootcd.iso /mnt

Continue reading →

If you run your Ubuntu system behind a firewall and have to use proxy server for http and ftp access, then your apt-get on a newly installed Ubuntu system will probably not work.

To make it use proxy, simply set the http_proxy environment variable. Once you get it working (try something like apt-get update), you'll probably want to add it to your .bashrc file.

Continue reading →

I've recently upgraded Apache and PHP on my VPS, and one of the unpleasant surprises was that some scripts which tried including pages from remote sites (I know, not the most secure approach, but there were reasons for that) got broken.

allow_url_fopen

Traditionally, all the websites Google finds suggest that you double-check that your php.ini config has the allow_url_fopen enabled:

allow_url_fopen = On

Continue reading →

If you have used your fresh Ubuntu install for longer than half an hour, chances are that you've discovered the sudo command already.

sudo allows certain users to execute a command under another user's privileges. Most commonly, using sudo implies running a command as a superuser, but the approach works equally well for allowing you to inherit a user ID (uid) and group ID (gid) of any user on the system.

To gain access, a password is asked, and by default it is your password, and not the password of a user you're trying to run a command as. This allows for the system' s administrator to effectively manage user privileges without having any user share their password.

Continue reading →

Starting with RHEL4, the system only accepts local (socket-based) X11 server connections. This means that if you go to another Unix server and try forwarding X11 output by using DISPLAY variable to point to your RHEL4 box, it will no longer work.

Continue reading →

Different UNIX-like operating systems store information about their release versions differently. If you know what OS you have, but not sure about the version, then here's how you can find out:

RedHat Linux

bash-3.1$ cat /etc/redhat-release
Red Hat Enterprise Linux Client release 5 (Tikanga)

Continue reading →