The vnode table represents all file activity in UNIX. There is a unique vnode allocated in the vnode table for each active file, each current directory, each mounted-on file, text file, and the root. To see the number of vnodes available in Mac OS X, look to sysctl for the kern.maxvnodes variable using something similar to the following command: sysctl -A | grep vnode
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Regular Expressions
Basically, a regular expression is a pattern describing a certain amount of text. Their name comes from the mathematical theory on which they are based. But we will not dig into that. Since most people including myself are lazy to type, you will usually find the name abbreviated to regex or regexp. I prefer regex, because it is easy to pronounce the plural “regexes”. On this website, regular expressions are printed as regex. If your browser has proper support for cascading style sheets, the regex should be highlighted in red. This first example is actually a perfectly valid regex. It is the most basic pattern, simply matching the literal text…
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The Basics of pico (or nano)
At your Unix shell prompt, type: pico filename Replace filename with the name of the file you want to create or edit. For example, to create a file and name it indiana.txt, type: pico charles.txt If the file already exits, Pico opens it for you to edit. If it doesn’t exist yet, Pico creates it and places you in an editing buffer. Pico displays a menu bar of commonly-used commands at the bottom of the screen. Pico accepts commands from your keyboard but not from your mouse. To insert text into your Pico editing screen at the cursor, just begin typing. Pico inserts the text to the left of the…