Match/extract all characters between 2 strings - php

Question

I want to extract John Doe from the string \n*DRIVGo*\nVolledige naam: John Doe\nTelefoonnummer: 0612345678\nIP: 94.214.168.86\n
So I guess the regex pattern needs to extract all characters between 'Volledige naam:' and '\n'. Is there anyone who can help me out?

Answer 1

You may use this regex to capture the name in group 1,
naam:\s+([a-zA-Z ]+)
As the name can only contain alphabets and spaces hence use of [a-zA-Z ]+ charset.
Php sample codes,
$str = "\n*DRIVGo*\nVolledige naam: John Doe\nTelefoonnummer: 0612345678\nIP: 94.214.168.86\n";
preg_match('/naam:\s+([a-zA-Z ]+)/', $str, $matches);
print_r($matches[1]);
Prints,
John Doe
Online demo

Answer 2

You can use
^Volledige naam:\s*\K.+
in multiline mode. That is
^ # start of line
Volledige naam:\s*\K # Volledige naam:, whitespaces and "forget" what#s been matched
.+ # rest of the line
In PHP:
<?php
$string = <<<DATA
*DRIVGo*
Volledige naam: John Doe
Telefoonnummer: 0612345678
IP: 94.214.168.86
DATA;
$regex = '~^Volledige naam:\s*\K.+~m';
if (preg_match($regex, $string, $match)) {
print_r($match);
}
?>
See a demo on ideone.com as well as on regex101.com.

Answer 3

The required string exists constantly at indexOf(':') and ends at the same call using the previously obtained value of indexOf as the offset in the subsequent call. (Given that the first call doesn't indicate that the result was not found and also that result of the send call [which would indicate the complete segment is not contained in the string])
Using a regular expression for this seems less useful because the source string will not varry in some way which requires automata.
Consider a simple split('\n') operation [optionally given a length of matches to obtain] which can be followed by further such calls if necessary to obtain the desired value without the need of any underlying engine.
The logic provided would be the same as a Regex is doing for you with it's underlying implementation although the associated cost both in terms of memory and performance is usually only justified for certain scenarios [for instance involving code page or locale conversions but not limited to, another case would be finding words with incorrect Declension, Punctuation etc.] which in this case do not seem to be needed.
Consider a parser construct with fields and methods that can obtain [point to] and also verify the integrity of the data when requires; This will also allow you to quickly serialize and deserialize the results in most cases.
Finally since you indicated your language is PHP I figured I should also let you know that equivalent of indexOf is strpos and the following code will demonstrate various ways to solve this problem without the use of regex.
$str = "\n*DRIVGo*\nVolledige naam: John Doe\nTelefoonnummer: 0612345678\nIP: 94.214.168.86\n";
$search = chr(10);
$parts = explode($search, $str);
$partsCount = count($parts);
print_r($parts);
if($partsCount > 1) print($parts[1]); //*DRIVGo*
print('-----Same results via different methodology------');
$groupStart = 0;
$groupEnd = $groupStart;
$max = strlen($str);
//While the groupEnd has not approached the length of str
while($groupEnd <= $max &&
($groupStart = strpos($str, $search, $groupStart)) >= 0 && // find search in str starting at groupStart, assign result to groupStart
($groupEnd = strpos($str, $search, $groupEnd + 1)) > $groupStart) // find search in str starting at groupEnd + 1, assign result to groupEnd
{
//Show the start, end, length and resulting substring
print_r([$groupStart, $groupEnd, $groupEnd - $groupStart, substr($str, $groupStart, $groupEnd - $groupStart)]);
//advance the parsing
$groupStart = $groupEnd;
}