Command line tips & tricks - concatenation with cat

If you've done any sort of command line stuff on a Unix-like OS, you've probably come across cat. It stands for 'concatenate', but most often we use it to simply spit out the contents of a file, like this:

$ cat myfile

So hang on - why is it called concatenate if we're only showing the contents of one file? Well, if you give cat one file, it just ...

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Use key-based authentication with SSH

Back in November, I took a quick look at how to set up secure remote login with SSH.

It's really simple to login with your username/password combination on the remote machine, but sometimes it can be a better idea to use key-based authentication.

Key-based authentication is where instead of authenticating that you are you with the remote machine credentials, you use a cryptographic key pair. I won't ...

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Explanation of the hash-bang (#!)

If you do any amount of scripting with any Unix-like operating system, you are probably familiar with the hash-bang (also known as the shebang).

The hash-bang, put at the start of a script, instructs the OS to use the program following the #! to interpret the script. For example, if you've got a Perl script and you set the permissions to executable, you won't automatically be able to just ...

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