php man page for preg_last_error

PREG_LAST_ERROR(3)							 1							PREG_LAST_ERROR(3)

preg_last_error - Returns the error code of the last PCRE regex execution

SYNOPSIS
       int preg_last_error (void  )

DESCRIPTION
	Returns the error code of the last PCRE regex execution.

       Example #1

	      preg_last_error(3) example

	      <?php

	      preg_match('/(?:D+|<d+>)*[!?]/', 'foobar foobar foobar');

	      if (preg_last_error() == PREG_BACKTRACK_LIMIT_ERROR) {
		  print 'Backtrack limit was exhausted!';
	      }

	      ?>

	      The above example will output:

	      Backtrack limit was exhausted!

RETURN VALUES
	Returns one of the following constants (explained on their own page):

	      o PREG_NO_ERROR

	      o PREG_INTERNAL_ERROR

	      o PREG_BACKTRACK_LIMIT_ERROR (see also pcre.backtrack_limit)

	      o PREG_RECURSION_LIMIT_ERROR (see also pcre.recursion_limit)

	      o PREG_BAD_UTF8_ERROR

	      o PREG_BAD_UTF8_OFFSET_ERROR (since PHP 5.3.0)

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