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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
Supported property codes
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 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.

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:

Supported scripts
Arabic Armenian Avestan Balinese Bamum
Batak Bengali Bopomofo Brahmi Braille
Buginese Buhid Canadian_Aboriginal Carian Chakma
Cham Cherokee Common Coptic Cuneiform
Cypriot Cyrillic Deseret Devanagari Egyptian_Hieroglyphs
Ethiopic Georgian Glagolitic Gothic Greek
Gujarati Gurmukhi Han Hangul Hanunoo
Hebrew Hiragana Imperial_Aramaic Inherited Inscriptional_Pahlavi
Inscriptional_Parthian Javanese Kaithi Kannada Katakana
Kayah_Li Kharoshthi Khmer Lao Latin
Lepcha Limbu Linear_B Lisu Lycian
Lydian Malayalam Mandaic Meetei_Mayek Meroitic_Cursive
Meroitic_Hieroglyphs Miao 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
Sharada Shavian Sinhala Sora_Sompeng Sundanese
Syloti_Nagri Syriac Tagalog Tagbanwa Tai_Le
Tai_Tham Tai_Viet Takri Tamil Telugu
Thaana Thai Tibetan Tifinagh Ugaritic
Vai Yi        

The \X escape matches a Unicode extended grapheme cluster. An extended grapheme cluster is one or more Unicode characters that combine to form a single glyph. In effect, this can be thought of as the Unicode equivalent of . as it will match one composed character, regardless of how many individual characters are actually used to render it.

In versions of PCRE older than 8.32 (which corresponds to PHP versions before 5.4.14 when using the bundled PCRE library), \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 10 notes

up
16
huhwatnouDONTspamPLEASE at hotmail dot com
8 years ago
To select UTF-8 mode for the additional escape sequences (\p{xx}, \P{xx}, and \X) , use the "u" modifier (see http://php.net/manual/en/reference.pcre.pattern.modifiers.php).

I wondered why a German sharp S (ß) was marked as a control character by \p{Cc} and it took me a while to properly read the first sentence: "Since 5.1.0, three additional escape sequences to match generic character types are available when UTF-8 mode is selected. " :-$ and then to find out how to do so.
up
3
Steve
7 months ago
Examples are always useful! See https://unicodeplus.com/category for more.

C Other
Cc Control (Unicode code points in the ranges U+0000-U+001F and U+007F-U+009F)
Cf Format (Soft hyphen (U+00AD), zero width space (U+200B), etc.)
Cn Unassigned (Any code point that is not in the Unicode table)
Co Private use
Cs Surrogate (Characters in the range U+D800 to U+DFFF, which are invalid in utf-8)

L Letter
Ll Lower case letter (a-z, µßàáâãäåæçèéêëìíîïðñòóôõöøùúûüýþÿ and more)
Lm Modifier letter (Letter-like characters that are usually combined with others, but here they stand alone:
ʰʱʲʳʴʵʶʷʸʹʺʻʼʽʾʿˀˁˆˇˈˉˊˋˌˍˎˏːˑˠˡˢˣˤˬˮʹͺՙ and more)
Lo Other letter (ªºƻǀǁǂǃʔ and many more ideographs and letters from unicase alphabets)
Lt Title case letter (DžLjNjDzᾈᾉᾊᾋᾌᾍᾎᾏᾘᾙᾚᾛᾜᾝᾞᾟᾨᾩᾪᾫᾬᾭᾮᾯᾼῌῼ)
Lu Upper case letter (A-Z, ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖØÙÚÛÜÝÞ and more)
L& Ordinary letter (Any character that has the Lu, Ll, or Lt property)

M Mark
Mc Spacing mark (None in latin scripts)
Me Enclosing mark (Combining enclosing square (U+20DE) like in a⃞ , combining enclosing circle backslash (U+20E0) like in a⃠)
Mn Non-spacing mark (Combining diacritical marks U+0300-U+036f, like the accents on this letter a: áâãāa̅ăȧäảåa̋ǎa̍a̎ȁa̐ȃ)

N Number
Nd Decimal number (0123456789, ٠١٢٣٤٥٦٧٨٩ and digits in many other scripts.)
Nl Letter number (ⅠⅡⅢⅣⅤⅥⅦⅧⅨⅩⅪⅫⅬⅭⅮⅯⅰⅱⅲⅳⅴⅵⅶⅷⅸⅹⅺⅻⅼⅽⅾⅿ and some more)
No Other number (⁰¹²³⁴⁵⁶⁷⁸⁹ ₀₁₂₃₄₅₆₇₈₉ ½⅓⅔¼¾⅕⅖⅗⅘⅙⅚⅐⅛⅜⅝⅞⅑⅒ ①②③④⑤⑥⑦⑧⑨⑩⑪⑫⑬⑭⑮⑯⑰⑱⑲⑳, etc.)

P Punctuation
Pc Connector punctuation (_ underscore (U+005F), ‿ undertie U+203F, ⁀ character tie (U+2040), etc.)
Pd Dash punctuation (- hyphen-minus (U+002D), ‐ hyphen (U+2010), ‑ non-breaking hyphen (U+2011), ‒ figure dash (U+2012),
– en dash (U+2013), — em dash (U+2014), ― horizontal bar (U+2015), etc.)
Pe Close punctuation (right parenthesis, bracket, or brace: `)` (U+0029), `]` (U+005D), `}` (U+007D), etc.)
Pf Final punctuation (right quotation marks: » (U+00BB), ’ (U+2019), ” (U+201D), etc.)
Pi Initial punctuation (left quotation marks: « (U+00AB), ‘ (U+2018), “ (U+201C), etc.)
Po Other punctuation (!"#%&'*,./:;?@\¡§¶·¿)
Ps Open punctuation (left parenthesis, bracket, or brace: `(` (U+0028), `[` (U+005B), `{` (U+007B), etc.)

S Symbol
Sc Currency symbol ($¢£¤¥, ₠ ₡ ₢ ₣ ₤ ₥ ₦ ₧ ₨ ₩ ₪ ₫ € ₭ ₮ ₯ ₰ ₱ ₲ ₳ ₴ ₵ ₶ ₷ ₸ ₹ ₺ ₻ ₼ ₽ ₾ ₿ (U+20A0-U+20BF), etc.)
Sk Modifier symbol (Symbol-like characters that are usually combined with others, but here they stand alone:
^`¨¯´¸ and more)
Sm Mathematical symbol (+<=>|~¬±×÷϶ and many more)
So Other symbol (¦ broken bar (U+00A6), © copyright sign (U+00A9), ® registered sign (U+00AE), ° degree sign (U+00B0);
arrows, signs, emojis and many many more)

Z Separator
Zl Line separator (line separator (U+2028))
Zp Paragraph separator (paragraph separator (U+2029))
Zs Space separator (space, no-break space, en quad, em quad, en space, em space, figure space, thin space, hair space, etc.)
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10
mercury at caucasus dot net
13 years ago
An excellent article explaining all these properties can be found here: http://www.regular-expressions.info/unicode.html
up
8
xuantoaiph at gmail dot com
10 years ago
My country, Vietnam, have our own alphabet table:
http://en.wikipedia.org/wiki/Vietnamese_alphabet
I hope PHP will support better than in Vietnamese.
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3
o_shes01 at uni-muenster dot de
13 years ago
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
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2
suit at rebell dot at
14 years ago
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
}
?>
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0
php at lnx-bsp dot net
6 years ago
Not made clear in the top of page explanation, but these escaped character classes can be included within square brackets to make a broader character class. For example:

<?php preg_match( '/[\p{N}\p{L}]+/', $data ) ?>

Will match any combination of letters and numbers.
up
0
Yzmir Ramirez
10 years ago
If you are working with older environments you will need to first check to see if the version of PCRE will work with unicode directives described above:

<?php

// Need to check PCRE version because some environments are
// running older versions of the PCRE library
// (run in *nix environment `pcretest -C`)

$allowInternational = false;
if (
defined('PCRE_VERSION')) {
if (
intval(PCRE_VERSION) >= 7) { // constant available since PHP 5.2.4
$allowInternational = true;
}
}
?>

Now you can do a fallback regex (e.g. use "/[a-z]/i"), when the PCRE library version is too old or not available.
up
-5
o_shes01 at uni-muenster dot de
13 years ago
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
up
-3
phpnet at N_O_S_P_A_M dot osps dot net
1 year ago
I found the predefined "supported" scripts helpful, except that there's no apparent definition of what Unicode character ranges are covered by those definitions. So I wrote this to determine them and print out the equivalent PCRE character class definitions. An example fragment of output is (I can't include all output due to PHP.net Note-posting limits)

Canadian_Aboriginal=[\x{1400}-\x{167f}\x{18b0}-\x{18f5}]

The program:

<?php

$scriptNames
= array(
'Arabic',
'Armenian',
'Avestan',
'Balinese',
'Bamum',
'Batak',
'Bengali',
'Bopomofo',
'Brahmi',
'Braille',
'Buginese',
'Buhid',
'Canadian_Aboriginal',
'Carian',
'Chakma',
'Cham',
'Cherokee',
'Common',
'Coptic',
'Cuneiform',
'Cypriot',
'Cyrillic',
'Deseret',
'Devanagari',
'Egyptian_Hieroglyphs',
'Ethiopic',
'Georgian',
'Glagolitic',
'Gothic',
'Greek',
'Gujarati',
'Gurmukhi',
'Han',
'Hangul',
'Hanunoo',
'Hebrew',
'Hiragana',
'Imperial_Aramaic',
'Inherited',
'Inscriptional_Pahlavi',
'Inscriptional_Parthian',
'Javanese',
'Kaithi',
'Kannada',
'Katakana',
'Kayah_Li',
'Kharoshthi',
'Khmer',
'Lao',
'Latin',
'Lepcha',
'Limbu',
'Linear_B',
'Lisu',
'Lycian',
'Lydian',
'Malayalam',
'Mandaic',
'Meetei_Mayek',
'Meroitic_Cursive',
'Meroitic_Hieroglyphs',
'Miao',
'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',
'Sharada',
'Shavian',
'Sinhala',
'Sora_Sompeng',
'Sundanese',
'Syloti_Nagri',
'Syriac',
'Tagalog',
'Tagbanwa',
'Tai_Le',
'Tai_Tham',
'Tai_Viet',
'Takri',
'Tamil',
'Telugu',
'Thaana',
'Thai',
'Tibetan',
'Tifinagh',
'Ugaritic',
'Vai',
'Yi'
);
$scriptTypes = array();
foreach(
$scriptNames as $n ) $scriptTypes[ $n ] = array();
for(
$i=0; $i <= 0x10fff; $i++ ) {
//echo $i.PHP_EOL;
foreach( $scriptNames as $scriptName ) {

if (
preg_match( '/[\p{'. $scriptName .'}]/u', mb_chr( $i, 'UTF-8') ) ) {

if (empty(
$scriptTypes[ $scriptName ])
|| ( (
$i - $scriptTypes[ $scriptName ][ count( $scriptTypes[ $scriptName ] ) - 1 ][1]) > 1)
) {

$scriptTypes[ $scriptName ][] = [$i, $i];

} else {

$scriptTypes[ $scriptName ][ count( $scriptTypes[ $scriptName ] ) - 1 ][1] = $i;
}
}
}
}
foreach(
$scriptTypes as $scriptName => $unicodeRanges ) {

printf(
'%s=[',
$scriptName
);
foreach(
$unicodeRanges as $r ) {

printf(
'\x{%04x}',
$r[0]
);
if (
$r[1] > $r[0] )
printf(
'-\x{%04x}',
$r[1]
);
}
printf(
']'.PHP_EOL
);
}
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