We'll come back to Unit 11. Unit 12 is shorter, and we can get it done before lunch, says the instructor. Unit 12: Introduction To String Processing + head displays the first 10 lines (default) of a file. + tail displays the last 10 lines (default) of a file. + wc ("word count") counts words, lines, and characters in a file. + sort sorts text to stdout, on a line-by-line basis. + uniq filters successive duplicate lines in a file. You will need to sort a file ...

The class is still interesting. The notes are still boring. Previous installments can be found by searching my JU blog. Don't bother, though. Unit 10: Advanced Topics in Users, Groups, and Permissions User and Group ID Numbers + User names map to UID numbers. + Group names map to GID numbers. + Data is associated with UID and GID, not Username and Group name. + More importantly, two different usernames with two different passwords can have the same UID. In that case...

If you've gotten this far, you should see all the previous installments on the right. Don't bother reading them, though. They're amazingly boring. This installment won't be much better. Unit 6: Users, Groups, and Permissions Oh my! The Linux Security Model + Users, Groups, and Other + root is not a normal User, nor is it Other. root sits above most security features. + Every process has a User and Group association. Processes can only access resources that ar...

The third installment . (http://stutefish.joeuser.com/index.asp?AID=75646) Unit 4: The bash Shell Whoohoo! (the bang denotes sincerity) + Backward compatible with the Bourne shell (sh) + Apparently the de facto Linux standard shell Some bash Features + Command line completion: TAB + Command line editing + Command line history: history history has a 1k-command buffer and remembers your previous session(s), too. Use bangs to invoke previous commands by n...

The second installment (http://stutefish.joeuser.com/index.asp?AID=75633). Linux File Hierarchy Concepts + Single-rooted, inverted-tree structure + "Root" is represented by a "/" symbol. + Case sensitive element names + Slash-delimited paths (e.g. "/usr/home/asshat") Some Important Directories + Home directories (e.g., "/root", "/home/ ") + Binary directories (e.g., "/bin", "/usr/bin") + System binary directories (e.g., "/sbin", "/usr/sbin", "/usr/local/sbin"...

The first installment (http://stutefish.joeuser.com/index.asp?AID=75620) Unit 2 Running Commands + Syntax: command [options] [arguments] + Each syntax item is space-delimited + Options modify the command's behavior (e.g., "ls -l", "ls -a") + Full-word options usually preceded by "--" + Single-letter options usually preceded by "-" (e.g., "-a, -b, -c" or "-abc") + Arguments are additional info like filenames that the command requires (e.g., "ls -l /bin", where "...

Yeah, so I'm in Red Hat training, finally. I've only been supporting a major Linux-based project here at work for over six months now.[1] So here's some notes, taken during class. Unit 1 UNIX History Bla bla bla. UNIX Principles + Everything is a file + Including hardware (!) + Configuration data is stored in text (files) + Small, single-purpose programs + Avoids captive user interfaces (whatever that means) + The ability to chain programs together to per...

Have you ever been frozen out by a woman? Guys, you know what I mean. You say or do the wrong thing, and suddenly POW! She won't talk to you. She won't even look at you. She just sits there, saying nothing, radiating massive, pummeling, icy waves of anger and frustration. There's nothing you can do about it, except bundle up against the cold and wait for the chill to pass. At times like this, you find yourself wishing for an argument, a shouting match, anything to warm things up a bi...