Get alpha characters and stop when special character detected

[gcue]

Hi world

I am trying to get JNNR or JZU from these strings. 

$zip_file = "JNNR.zip"
$zip_file = "JZU-(excel).zip"

There can be different number of alpha characters and either in lower/uppercase.  I would like to stop when a special character is detected (in other words remove anything after a special character including a space is detected)

Here is what I've tried so far - feel like I'm getting close but cant seem to figure it out

$initials = StringRegExpReplace($zip_file, "([A-Z])\w+[^a-z0-9]*", "")

thank you in advance!

[mikell]

Did you say "alpha" ? 

$initials = StringRegExpReplace($zip_file, '^([[:alpha:]]+).*$', "$1")

[gcue]

works great!

just for my knowledge i am trying to understand the need for 2 brackets?  and how the dollar sign works?  is it to consider a new line?

thank you so very much!!!!

[Musashi]

1 hour ago, gcue said:

i am trying to understand the need for 2 brackets?

I'm sure @mikell can explain it much better . Anyway, have a look at the StringRegExp help (in particular : Character classes and POSIX classes).

The outer brackets represent a character class, which means a defined set of allowed/disallowed characters .  

The inner brackets represent a POSIX class, here [:alnum:]

So if you use a POSIX class within a character class ,the notation is  [[:alnum:]]

[mikell]

23 minutes ago, Musashi said:

I'm sure @mikell can explain it much better

No no it was absolutely perfekt - and pretty good for my laziness btw, so thank you 

The holy Help File says :
POSIX classes : These are named sets specifications to be used themselves within a character class
It says too (see "Anchors") :
the dollar matches at the end of the subject text, and also just before a newline sequence if option (?m) is active

[gcue]

very helpful thanks again!

[jchd]

Shameless plug: the AutoIt regex help is there for you.