<?php

$log = <<<FIM
##################################################
----------------------------------------
Nome: nome_user,
Email: email@user.com,
-------------------------------
,
----------------------------------------
##################################################
FIM;

	echo my_extract( $log, 'Email:', ',' ) . PHP_EOL;
	echo my_extract( $log, 'Nome:', ',' ) . PHP_EOL;
	echo my_extract( $log, 'Batata:', ',' ) . PHP_EOL;


    function my_extract( $text, $start, $end ) {
    	$pos1 = strpos( $text, $start );
		if( false === $pos1 ) return 'Não encontrado';
		$pos1 += strlen( $start );
		$pos2 = strpos( $text, $end, $pos1 );
		return trim( substr( $text, $pos1, $pos2 - $pos1 ) );
    }