Detect if PCRE was built without the --enable-unicode-properties or --enable-utf8 configuration switches
- by Mark Baker
I've a PHP library that uses a number of regular expressions featuring the \P expressions for multibyte strings, e.g.
((((?:\P{M}\p{M}*)+?)|(\'[^\']*\')|(\"[^\"]*\"))!)?\$?([a-z]{1,3})\$?(\d+)
While this works on most builds, I've had a few reports of the regexp returning an error.
Depending on Operating platform, the error messages from PCRE are:
Compilation failed: PCRE does not support \L, \l, \N, \P, \p, \U, \u, or \X at offset n
or
Compilation failed: support for \\P, \\p, and \\X has not been compiled at offset n
I know that I can probably test a regexp at the beginning of my code that uses \P, and trap for a returned error, then use that response to set a compatibility flag and provide a degraded (non UTF-8) regexp without the \P within the main body of my code based on that compatibility flag; but I was wondering if there was any simpler way to identify whether PCRE had been built without the --enable-unicode-properties or --enable-utf8 configuration switches. PHP provides access to PCRE_VERSION constant, but that won't help identify whether \P support is enabled or not.
