Regex in dynamic string X characters, in dynamic content

Question

Next, I have a page that generates a shuffled content with dynamic and non-dynamic strings, I need to take a dynamic value between separators |, it contains random data/strings around, which change when loading the page. The variable I want to pick has a fixed number of 32 characters composed of letters, numbers and _ (a-zA-Z0-9_).

Example:

PAGE CONTENTS

...new "x";test>'ok'=blabla-bla;||inicio||var77|var2|44AsFGq72A7_7Aq770vAr45|variavel|randomvariavel75|87df".fim("0"...

I wish to take the value of 33 characters (44AsFGq72A7_7Aq770vAr45) but I don’t know how because when the page is updated the values of the Lada of the 23 characters change order, and the string itself also because it is random.

Example page update.

(PS: The start and end values are always in the same place)

...new "x";test>'ok'=blaalb-bla;||inicio||r_a_n_d99|var2|84DF8|7s79DFGDsf8ssfs84D84d8D|var77|8526".fim("0"...

I need to use regex in the php to take this random variable on this random page excluding any other code that may appear.

Is there any way to do that?

Answer 1

$str = 'new "x";test>\'ok\'=blabla-bla;||inicio||var77|var2|44AsFGq72A7_7Aq770vAr45|variavel|randomvariavel75|87df".fim("0"...';
preg_match_all( '/\|[a-zA-Z0-9_]{23}\|/' , $str , $out );
print_r( $out );

You can use {N} to set the length of the string you want to find. In the above example you will find the 23-character string containing a-zA-Z0-9_ that is within the bounder |.

Output: 44AsFGq72A7_7Aq770vAr45

Example in Ideone

Answer 2

As @Papacharlie commented you can use {N} to delimit the exact number of characters of wish.

As for regex:

You can use the auxiliary \w which it rightly represents a-zA-Z0-9_

preg_match( '~(?<=\|)(\w{23})(?=\|)~' , $str , $out );

(?<=\|) auxiliary - should contain before, but not capture
(?=\|) auxiliary - must contain afterwards, but not capture

or simply

preg_match( '~\|(\w{23})\|~' , $str , $out );
$var = $out[1]; the value will be in group 1;