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Mastering cat

A fictitious (literally, it's not a real book) book about mastering the UNIX/Linux 'cat' command. "Written" by Shlomi Fish, the acclaimed author of 'Mastering rm', and 'Mastering mv'.
O'Reilly Net: Hi Shlomi!

Shlomi Fish: Hi!

O'Reilly Net: So, what has motivated you to write the book?

Shlomi Fish: Well, I realised people use cat so often that they don't take the time to fully investigate it and learn it. For example, many people I worked with believed that cat can only be used to output one file at a time. So to output several files they used something like:

(cat file1.txt ; cat file2.txt ; cat file3.txt) | command

The horror! cat accepts several files as arguments. So you can write it as:

cat file1.txt file2.txt file3.txt | command

This has motivated me to write the book, to make people fully understand the command.

O'Reilly Net: Isn't mastering cat supposed to be quite easy? Does it really necessitates its own book?

Shlomi Fish: Hell no! Mastering cat is not easy at all. In fact, mastering cat is almost as difficult as herding cats.

For example, one case where I found that people truly underestimate the power of cat is in the prefixing a line example. You can do that with:

echo "This would be the first line" | cat - myfile.txt > myfile.txt.new
mv -f myfile.txt.new myfile.txt

But people do not realize that and instead opted to use sed, awk, or even perl (!). It can be taken further, of course. If the prefix is already in its own file, you can simply use cat prefix.txt myfile.txt

Of course, if you want to append the same text to both the start and the end of a file, you can't do that with cat - myfile.txt -. It simply doesn't work that way. So, I end up explaining a lot about UNIX pipeline concepts in the book.

O'Reilly Net: So what else does your book cover?

Well, I cover many things there. Among them are:

1. History of the cat command.

2. Differences between the various cat implementations. (GNU, the BSDs, System V, etc.)

3. cat equivalents in other operating systems (DOS, Win32, VMS, OS/390, etc.)

4. Overview of the GNU cat codebase (for programmers).

I'm also focusing on the various cat flags, which aid in its interactive use. For example the -E/--show-ends flag, that places dollar signs at the end of the lines.

Except for that I'm also covering dog which is a program that provides a superset of the cat program. I should also mention mouse which aimed to provide an even greater superset, and was never released. Rumors say some parts of it are based on code of the leaked Windows 2000 sources.

O'Reilly Net: Your book seems bound to be popular. (for some values of popularity) What can we expect from you next?

Shlomi Fish: Well, I hope many people will buy the book, or read it online so they'll be educated about cat. If you like "Mastering cat", look forward to my next book - "Mastering echo". I expect it to be published next fall.
by ivantis May 17, 2009
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Mastercock

The mammoth cock that always seems to show up when on the website chatroulette.com
oh man i gotta find me som titties on chatroulette.com. OH SHIT! MASTERCOCK! PRESS F9 PRESS F9!!!
by roosterstroke March 7, 2010
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Mastermonica

A vaginal disease in which a vagina develops a hunger and eats things.
"Damn, that mastermonica bitch ate my dick off."

"After my recent mastermonica infection, I no longer crave penises up in there as much as I do Vatamin C."

"Now that I have mastermonica I have to order food for two lips."
by Clarice Suckadick March 21, 2009
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casterton school

At Casterton school they're Slut Bags
by EPICLOL October 11, 2011
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Owen Masterson

A boy who flirts with every single girl on the planet, like anyone really.
"Yeah i saw billy flirting with another girl, she was our teacher!"
"damn he is such an owen masterson"
by Julia_penis_glitter January 23, 2018
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Masterliness

An indication of extreme approval and admiration. May be used towards any entity or object one desires to express extreme approval and/or admiration for. however, usually not used to describe girls. Maybe used with the prefix "the essence of", or by itself.
ok:

-"How was the concert?"
-"Masterliness!!"

"Dark Side of the Moon by Pink Floyd is the essence of masterliness"

"The weather's masterliness"

Not ok:

"Damn, that girl's tits are the essence of masterliness!" <<this sounds corny
by General G. Thompsky May 4, 2010
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Masterforebation

To make a mental porn of a person you know in your mind and performing the act of foreplay and masterbation simultaneously.
I remember that night..It was so epic. Performs masterforebation a different variation of the word Masterforeplaytion
by Suite Seduction November 20, 2011
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