Escape sequences
There is a possibility to use \p{xx} and \P{xx} escape sequences with script names.
From http://www.pcre.org/pcre.txt
When PCRE is built with Unicode character property support, three addi-
tional escape sequences that match characters with specific properties
are available. When not in UTF-8 mode, these sequences are of course
limited to testing characters whose codepoints are less than 256, but
they do work in this mode. The extra escape sequences are:
\p{xx} a character with the xx property
\P{xx} a character without the xx property
\X an extended Unicode sequence
The property names represented by xx above are limited to the Unicode
script names, the general category properties, "Any", which matches any
character (including newline), and some special PCRE properties
(described in the next section). Other Perl properties such as "InMu-
sicalSymbols" are not currently supported by PCRE. Note that \P{Any}
does not match any characters, so always causes a match failure.
Sets of Unicode characters are defined as belonging to certain scripts.
A character from one of these sets can be matched using a script name.
For example:
\p{Greek}
\P{Han}
Those that are not part of an identified script are lumped together as
"Common". The current list of scripts is:
Arabic, Armenian, Avestan, Balinese, Bamum, Bengali, Bopomofo, Braille,
Buginese, Buhid, Canadian_Aboriginal, Carian, Cham, Cherokee, Common,
Coptic, Cuneiform, Cypriot, Cyrillic, Deseret, Devanagari, Egyp-
tian_Hieroglyphs, Ethiopic, Georgian, Glagolitic, Gothic, Greek,
Gujarati, Gurmukhi, Han, Hangul, Hanunoo, Hebrew, Hiragana, Impe-
rial_Aramaic, Inherited, Inscriptional_Pahlavi, Inscriptional_Parthian,
Javanese, Kaithi, Kannada, Katakana, Kayah_Li, Kharoshthi, Khmer, Lao,
Latin, Lepcha, Limbu, Linear_B, Lisu, Lycian, Lydian, Malayalam,
Meetei_Mayek, Mongolian, Myanmar, New_Tai_Lue, Nko, Ogham, Old_Italic,
Old_Persian, Old_South_Arabian, Old_Turkic, Ol_Chiki, Oriya, Osmanya,
Phags_Pa, Phoenician, Rejang, Runic, Samaritan, Saurashtra, Shavian,
Sinhala, Sundanese, Syloti_Nagri, Syriac, Tagalog, Tagbanwa, Tai_Le,
Tai_Tham, Tai_Viet, Tamil, Telugu, Thaana, Thai, Tibetan, Tifinagh,
Ugaritic, Vai, Yi.
Each character has exactly one Unicode general category property, spec-
ified by a two-letter abbreviation. For compatibility with Perl, nega-
tion can be specified by including a circumflex between the opening
brace and the property name. For example, \p{^Lu} is the same as
\P{Lu}.
If only one letter is specified with \p or \P, it includes all the gen-
eral category properties that start with that letter. In this case, in
the absence of negation, the curly brackets in the escape sequence are
optional; these two examples have the same effect:
\p{L}
\pL
Unicode character properties
Since 5.1.0, three additional escape sequences to match generic character types are available when UTF-8 mode is selected. They are:
- \p{xx}
- a character with the xx property
- \P{xx}
- a character without the xx property
- \X
- an extended Unicode sequence
The property names represented by xx above are limited to the Unicode general category properties. Each character has exactly one such property, specified by a two-letter abbreviation. For compatibility with Perl, negation can be specified by including a circumflex between the opening brace and the property name. For example, \p{^Lu} is the same as \P{Lu}.
If only one letter is specified with \p or \P, it includes all the properties that start with that letter. In this case, in the absence of negation, the curly brackets in the escape sequence are optional; these two examples have the same effect:
\p{L}
\pL
| Property | Matches | Notes |
|---|---|---|
| C | Other | |
| Cc | Control | |
| Cf | Format | |
| Cn | Unassigned | |
| Co | Private use | |
| Cs | Surrogate | |
| L | Letter | Includes the following properties: Ll, Lm, Lo, Lt and Lu. |
| Ll | Lower case letter | |
| Lm | Modifier letter | |
| Lo | Other letter | |
| Lt | Title case letter | |
| Lu | Upper case letter | |
| M | Mark | |
| Mc | Spacing mark | |
| Me | Enclosing mark | |
| Mn | Non-spacing mark | |
| N | Number | |
| Nd | Decimal number | |
| Nl | Letter number | |
| No | Other number | |
| P | Punctuation | |
| Pc | Connector punctuation | |
| Pd | Dash punctuation | |
| Pe | Close punctuation | |
| Pf | Final punctuation | |
| Pi | Initial punctuation | |
| Po | Other punctuation | |
| Ps | Open punctuation | |
| S | Symbol | |
| Sc | Currency symbol | |
| Sk | Modifier symbol | |
| Sm | Mathematical symbol | |
| So | Other symbol | |
| Z | Separator | |
| Zl | Line separator | |
| Zp | Paragraph separator | |
| Zs | Space separator |
Extended properties such as "Greek" or "InMusicalSymbols" are not supported by PCRE.
Specifying case-insensitive (caseless) matching does not affect these escape sequences. For example, \p{Lu} always matches only upper case letters.
The \X escape matches any number of Unicode characters that form an extended Unicode sequence. \X is equivalent to (?>\PM\pM*).
That is, it matches a character without the "mark" property, followed by zero or more characters with the "mark" property, and treats the sequence as an atomic group (see below). Characters with the "mark" property are typically accents that affect the preceding character.
Matching characters by Unicode property is not fast, because PCRE has to search a structure that contains data for over fifteen thousand characters. That is why the traditional escape sequences such as \d and \w do not use Unicode properties in PCRE.
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User Contributed Notes
Unicode character properties
hayk at mail dot ru
03-Mar-2011 01:46
o_shes01 at uni-muenster dot de
22-Jan-2011 06:23
For those who wonder: 'letter_titlecase' applies to digraphs/trigraphs, where capitalization involves only the first letter.
For example, there are three codepoints for the "LJ" digraph in Unicode:
(*) uppercase "LJ": U+01C7
(*) titlecase "Lj": U+01C8
(*) lowercase "lj": U+01C9
o_shes01 at uni-muenster dot de
21-Jan-2011 10:08
For those who wonder: 'letter_titlecase' applies to digraphs/trigraphs, where capitalization involves only the first letter.
For example, there are three codepoints for the "LJ" digraph in Unicode:
(*) uppercase "LJ": U+01C7
(*) titlecase "Lj": U+01C8
(*) lowercase "lj": U+01C9
mercury at caucasus dot net
08-May-2010 10:32
An excellent article explaining all these properties can be found here: http://www.regular-expressions.info/unicode.html
suit at rebell dot at
01-Mar-2010 05:13
these properties are usualy only available if PCRE is compiled with "--enable-unicode-properties"
if you want to match any word but want to provide a fallback, you can do something like that:
<?php
if(@preg_match_all('/\p{L}+/u', $str, $arr) {
// fallback goes here
// for example just '/\w+/u' for a less acurate match
}
?>