Installation

The PCRE extension is a core PHP extension, so it
is always enabled. By default, this extension is compiled using the
bundled PCRE library. Alternatively, an external PCRE library can
be used by passing in the –with-pcre-regex=DIR configuration
option where DIR is the location of PCRE’s include and
library files. It is recommended to use PCRE 8.10 or newer for PHP
5.6 and 7.0.

As of PHP 7.0.0 PCRE’s just-in-time compilation is
supported by default, which can be disabled with the –without-pcre-jit configuration option
as of PHP 7.0.12.

The Windows version of PHP has built-in support
for this extension. You do not need to load any additional
extensions in order to use these functions.

Note:

Before PHP 5.3.0, this extension could be disabled
by passing in the –without-pcre-regex configuration
option.

PCRE is an active project and as it changes so does
the PHP functionality that relies upon it. It is possible that
certain parts of the PHP documentation is outdated, in that it may
not cover the newest features that PCRE provides. For a list of
changes, see the » PCRE library changelog and also
the following bundled PCRE history: