A PHP regex that just won't work

A PHP regex that just won't work

References

Reference NO 1

http://stackoverflow.com/questions/10661024/why-wont-this-regex-work-with-file-reading-and-php-it-works-for-other-files-th

Reference NO 2

http://stackoverflow.com/questions/2541851/regular-expression-just-group-dont-capture-doesnt-seem-to-work

Reference NO 3

http://php.net/manual/en/function.preg-replace.php

Reference NO 4

https://bugs.php.net/bug.php?id=49594

Reference NO 5

http://php.net/manual/en/ref.regex.php

Reference NO 6

http://php.net/manual/en/function.split.php

Reference NO 7

#EANF#

Reference NO 8

#EANF#