Category: Linux/Unix/BSD

Information And Reviews On Linux, Unix And Bsd Operating Systems

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.

Show the headers only for a request with cURL

cURL is an extremely useful command line tool for making HTTP requests and can be used for diagnosing errors, downloading content and so. But what if you just want to see the response headers to see, for example, if a page is doing the right sort of redirect?

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Failed to add the host to the list of known hosts

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.

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How to tunnel port 25 with SSH

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.

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