Can you explane string ?

[dirty]

i opened one of the cods found here which converts what ever script filename is into a string.

for example if my script filename is "test.au3" then this variable will be "test"

StringRegExpReplace(@ScriptName, "\.[^\.]*$", "")

My question is:

i almost want to say %&$#&^%$ is this ? but dont want to get in trouble so ill ask this:

Whats all those "\.[^\.]*$" and what they mean and how they work ?

All i know when it comes to directories, is that if you put ".\whatever" means it will go one directory UP like CMD, but this is like a whole language of characters i dont get.

[czardas]

The answer can be found by reading about StringRegExp.in the help file.

Edited October 24, 2011 by czardas

[dirty]

so ure saying that "\.[^\.]*$" is something connected to a function and not just some weird characters that do something with the string ?

[guinness]

Did did you read the topic czardas suggested? Search google for topics about 'regular expressions', there it will give you a definition of what precisely a regular expression is, not a 'bunch of random characters thrown together without thought!'

Edited October 24, 2011 by guinness

[czardas]

Yes, it says : Any string of characters other than backslash or dot appearing after a backsalsh or dot until the end of the line.

I had to think about this a bit - now I think it says : Any string of characters other than a dot appearing after a dot until the end of the line.

So for example:

#include <Array.au3>
 
$regexp = StringRegExp("path\..\app.exe", "\.[^\.]*$", 3)
_ArrayDisplay($regexp)

Edited October 24, 2011 by czardas

[dirty]

hmm interesting.

thanks !

[Robjong]

Hi,

Those "weird characters" are a pattern to tell the regular expression engine how to modify the string, to strip the extension of a file name in this case.

However the pattern is a little bit off, here is my take on it.

"\.[^.]+$"

The pattern starts to match a dot (.), but since the dot is meta-character (modifier) in a regular expression it needs to be escaped, this is done with a backslash (\), so we get:

\.

The next part matches anything that is not a dot.

Anything inside of square brackets is a character set and it will match any character in the set, but in this case the caret (^) tells the engine to match any charter NOT in the set.

The plus (+) after the character set makes the engine match as many characters as possible, but only the ones in the character set and in a continuous stream.

_{* Note that the dot (.) has not been escaped here, this is because inside the character set it is not a meta-character.}

[^.]+

The dollar sign ($) represents the end of the string so the pattern will only be valid at the end of the string.

$

So the pattern matches the last dot and the characters behind it until the end of the string.

Here are some resources:

http://www.autoitscript.com/autoit3/docs/functions/StringRegExp.htm

http://www.regular-expressions.info/

https://developer.mozilla.org/en/Javascript/Guide/Regular_Expressions

http://www.zytrax.com/tech/web/regex.htm

http://www.php.net/manual/en/pcre.pattern.php

Hope this helps clear it up a little.

Edited October 25, 2011 by Robjong