When you are trying to work on changing the design of your website, you have to be concerned with the width of the pictures in your article content. I’ve got notoriously large screenshots on most of the articles I’ve written, so if I want to increase the sidebar it’s critical to figure out which pictures are going to be too wide to fit in the new design.
Whether you are responsible for a server or just a programmer doing development, you’ll often have more than one logfile that you want to track at the same time. There’s a nifty little utility for Linux called MultiTail that allows you to monitor multiple logs in a single window, instead of requiring multiple separate shell windows open.
One of the best features in Linux is the way you can control processes from the command line, so if you have an application that locks up your GUI, you can always SSH over from another machine and just kill the offending process.
One of my favorite features from Linux is the Alt + Window drag that allows you to move any window by holding down the Alt key and then just left-click dragging the window anywhere you’d like.
Ubuntu Gutsy is the latest major release of the most popular Linux distro, released on October 18, 2007. Like all Linux distributions you can upgrade easily even while the release is in beta, but now that it’s been released you should have much better luck with it.
If you are running Ubuntu and want to use the Tomcat servlet container, you should not use the version from the repositories as it just doesn’t work correctly. Instead you’ll need to use the manual installation process that I’m outlining here.
Has this ever happened to you? I created a new virtual machine running Ubuntu on my VMware server before I left home, but forgot to install the ssh server… so I couldn’t get to that machine at all from my remote location. Rather than driving back home I decided to find a solution.
A couple of weeks ago when I posted the last Great Geek Sites roundup I had included Jatecblog, a great new blog covering Linux and open source topics. Since that time their blog went down because of hosting problems.
While working on the instructions for compiling MonoDevelop from source, I relied heavily on the dpkg and apt-cache commands to tell me what was already installed vs what packages were available in the repository. After completing that article it occurred to me that I should explain how to show what packages are currently installed… so here we are.
After reading a post from my friend Daniel about the new release of MonoDevelop, I decided to try and install it… which is when I realized that the installation from source is so painful I’d better figure it out and share it with everybody else.
One of the biggest security holes you could open on your server is to allow directly logging in as root through ssh, because any cracker can attempt to brute force your root password and potentially get access to your system if they can figure out your password.
If you like the way Ubuntu requires you to enter your username and password instead of clicking on an icon, you can enable the same thing for Windows Vista in a somewhat similar style logon process. This is really most useful for home users, as domain users should already see this screen.
If you are tired of hacking together commands at the terminal or having to open a giant bloated IDE just to perform search and replace across a number of files, then Regexxer is the tool for you.
This tip won’t be useful for everybody, but for anybody with a dedicated server you’ll probably be familiar with this error message that gets sent weekly from the security scanner on your server.
One of the best ways to speed up your web application is to enable query caching in your database, which caches commonly used SQL queries in memory for virtually instant access by the next page that makes the same request.
If you’ve got an Ubuntu machine that you initially installed with Ubuntu Desktop, but would like to run as a server, you can just disable the graphical environment from starting up in order to save resources. This is also useful for doing system maintenance from the command line that needs to be performed outside of the GUI.
One of the things in Ubuntu that has always driven me crazy is the addition of new items into the grub menu without removing the old entries that likely don’t even work anymore. I’m sure most experienced Ubuntu users already know how to do this, but here’s the method anyway.
Virtualization Technology (VT) is a set of enhancements to newer processors that improve performance for running a virtual machine by offloading some of the work to the new cpu extensions. Both AMD and Intel have processors that support this technology, but how do you tell if your system can handle it?
The calculator options on Linux just blows the Windows calculator away. Imagine a calculator where you can solve extremely complicated expressions, or just convert between different measurements, and you’ve got Qalculate.
I’m the type of geek that has an SSH client open at all times, connected to my most frequently used servers so that I have instant access for monitoring and anything else. As such, it irritates me greatly when I get disconnected, so I’m sharing a few methods for keeping your session alive.
Every time I connect to my Ubuntu development server through my ssh client, I receive the same message and I’m getting tired of seeing it, so I decided to change the message to something else.
How often have you typed in a command in your linux shell, and then realized that you forgot to type sudo, so you end up with an error or editing the dreaded read-only file? This happens to me much more than I’d like to admit, so I’m writing about it.
If you are doing a lot of testing of different builds, there’s nothing more annoying than rebooting and then having the system boot into the wrong choice on the grub menu before you have a chance to pick the one you want. Reader Victor wrote in with this tip: You can just comment out the timeout line entirely to stop grub from picking anything, giving you time to get your morning coffee.
I realize this is probably only relevant to about 3 of the readers, but I’m posting this so I don’t forget how to do it myself! In my efforts to ban the completely insecure FTP protocol from my life entirely, I’ve decided to disable the FTP service running on the How-To Geek server, which is running the CentOS operating system.
Let’s say you have a directory with hundreds of files with the wrong file names, and you’d like to replace every filename containing test with prod. (this is a contrived example). We can easily do this with the “for” command in bash, combined with a little bit of bash goodness. Today we’ll learn how to replace text in a variable in a for loop.