Unix is a multi-user, multi-tasking operating system that was initially developed by Bell Labs in the 1970s. Various similar operating systems that are POSIX compliant (ie compatible with Unix) have since been developed (POSIX is an abbreviation for Portable Operating System Interface for UNIX). These include the following: the BSD family (OpenBSD, FreeBSD, NetBSD, Mac OS/X), Solaris, IRIX, AIX, SunOS, UnixWare, OpenServer and Linux.
Software written for POSIX compliant operating systems is generally able to be compiled for all POSIX platforms with little or no platform-specific changes. This makes the commands and utilities available for this extended family of operating systems very similar, and there are few differences between administering them.
The articles in this section are about useful command line utilities and commonly used application software on POSIX compliant operating systems. For Mac OSX specific articles see my OSX section.
This post looks at the error message "mysql-server : Depends: mysql-server-5.1 but it is not going to be installed" when attempting to install MySQL on a fresh install of Debian 6, when Debian 7 is the current up to date distro.
I recently reinstalled the operating system on my MacBookPro and discovered when trying to SSH into a new server for the first time I was getting the error "Failed to add the host to the list of known hosts (/Users/chris/.ssh/known_hosts)." This post shows what I needed to do to fix them problem.
If you’re a web developer like me who needs to test sending emails from a development version of a website, but your ISP blocks port 25 outbound, then it’s possible to set up a "tunnel" via SSH. You then send mail to port 25 on localhost and it actually sends the mail from the server at the other end.
When migrating a mono application / web service running on one server to a new server I got an error telling me that the "Argument cannot be null" and "Parameter name: path". This post shows the full error message and the additional configuration options that needed to be set to fix it.
Lynx is a command line web browser which I often use for checking the behaviour of redirection headers and content types in a web page’s http headers. The previous post showed how to get the headers with Lynx and this post how to set the user agent.
Lynx is a command line web browser which I often use for checking the behaviour of redirection headers and content types in a web page’s http headers. This first post shows how to get the headers and the second post how to set the user agent.