Unix Shell: The Art of I/O Redirection

One of the primary tricks in my sysadmin bag-o-tricks is Input/Output Redirection; I have found that while many people use Shell I/O Redirection throughout their day not everyone fully understands why and how it works. The Input and Output In the Unix environment there is always 3 streams open stdin, stdout, & stderr; these special streams are used for interacting with the user input and program output within the Unix/Linux shell environment....

 · 4 min · Benjamin Cane

Sysadmin Tools: Managing Linux from a Windows Desktop

While it is getting more common for companies to allow their IT staff to choose their own OS not every company allows this. In fact most companies require their IT staff to use Windows, as Windows has historically been the dominate OS for the business world. While I personally believe it is easier to administer Linux/Unix servers using a Linux desktop this doesn't mean that I get to be the exception to the rule; sometimes I have had to use a Windows desktop....

 · 5 min · Benjamin Cane

Linux Troubleshooting with strace

Today I want to cover one of the best troubleshooting tools in any sysadmins arsenal; strace. Strace is a command that will trace the system calls and signals from a specified command. What does that mean in layman's terms? Strace will output all of the inner workings of a process you run it against. If a process opens a file or binds a port, strace will print that action; it is a great utility for troubleshooting when a process is not behaving as expected and you can't find any reason in the commands output or log files....

 · 4 min · Benjamin Cane

Sudoedit: Securely allow users to edit files

Allowing unprivileged users to edit files that are normally beyond their rights is a task that is easy to perform however it requires a great deal of forethought to implement without opening security holes. You can give users the ability to edit privileged files by using User/Group Permissions, ACL's, or even sudo; but no matter which way you choose there are some things you must consider. For an example lets take a look at 2 files /etc/services and /etc/cron....

 · 4 min · Benjamin Cane

Why you should avoid running applications as root

I'm going to start this post by saying what I'm really thinking. 90% of the time if an application is running as the root user on a Unix/Linux machine; it is because the sysadmin who setup or designed the environment was being lazy. Now before getting offended, being a lazy sysadmin is a good thing. The fact is that most systems administrators are lazy in some way, and that is the reason why most systems administration tasks end up being scripted....

 · 3 min · Benjamin Cane