POSIX bracket expressions


show more POSIX bracket expressions provides you with in-depth training on Developer. Taught by Kevin Skoglund as part of the Using Regular Expressions show less
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POSIX bracket expressions

Back in Chapter 1, when we talked about the history of UNIX, we talked about the POSIX standardization that took place, and part of the POSIX standard was to come up with bracket expressions that would help define sets of characters. They are very similar to the character sets and the shorthand that we've been working with, but they do work a little bit different. First of all, they look very different. They all have square brackets around the outside, then colon next to that, followed by a keyword in the middle. So you can see, for example, that alpha is the keyword for all alphabetic characters. Now, it's a little bit more typing than our shorthand, but you can see how it's useful to get only the letters A through Z, whereas our shorthand, \w, included 0 through 9 and the underscore in that.

We can also specify upper- and lowercase letters. You can see there are keywords for lower and upper. That can be very handy as well. And then there's some for things like pick out all...

POSIX bracket expressions
Video duration: 4m 13s 5h 36m Intermediate

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POSIX bracket expressions provides you with in-depth training on Developer. Taught by Kevin Skoglund as part of the Using Regular Expressions

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Developer
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Regular Expressions
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