{"id":1266,"date":"2018-08-16T20:53:08","date_gmt":"2018-08-16T13:53:08","guid":{"rendered":"https:\/\/lagonet.vn\/?p=1266"},"modified":"2018-08-16T20:53:08","modified_gmt":"2018-08-16T13:53:08","slug":"regular-expression-cheat-sheets","status":"publish","type":"post","link":"https:\/\/kb.lagonet.vn\/?p=1266","title":{"rendered":"Regular Expression Cheat Sheets"},"content":{"rendered":"

PCRE Regex Cheatsheet<\/h2>\n

<\/p>\n

\n\n\n\n
\n\n\n\n\n\n\n\n\n\n
Regular Expression Basics<\/th>\n<\/tr>\n
.<\/td>\nAny character except newline<\/td>\n<\/tr>\n
a<\/td>\nThe character a<\/td>\n<\/tr>\n
ab<\/td>\nThe string ab<\/td>\n<\/tr>\n
a|b<\/td>\na or b<\/td>\n<\/tr>\n
a*<\/td>\n0 or more a’s<\/td>\n<\/tr>\n
\\<\/td>\nEscapes a special character<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n\n\n\n\n\n\n\n
Regular Expression Quantifiers<\/th>\n<\/tr>\n
*<\/td>\n0 or more<\/td>\n<\/tr>\n
+<\/td>\n1 or more<\/td>\n<\/tr>\n
?<\/td>\n0 or 1<\/td>\n<\/tr>\n
{2}<\/td>\nExactly 2<\/td>\n<\/tr>\n
{2, 5}<\/td>\nBetween 2 and 5<\/td>\n<\/tr>\n
{2,}<\/td>\n2 or more<\/td>\n<\/tr>\n
Default is greedy. Append ? for reluctant.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Regular Expression Groups<\/th>\n<\/tr>\n
(…)<\/td>\nCapturing group<\/td>\n<\/tr>\n
(?P<Y>…)<\/td>\nCapturing group named Y<\/td>\n<\/tr>\n
(?:…)<\/td>\nNon-capturing group<\/td>\n<\/tr>\n
(?>…)<\/td>\nAtomic group<\/td>\n<\/tr>\n
(?|…)<\/td>\nDuplicate group numbers<\/td>\n<\/tr>\n
\\Y<\/td>\nMatch the Y’th captured group<\/td>\n<\/tr>\n
(?P=Y)<\/td>\nMatch the named group Y<\/td>\n<\/tr>\n
(?R)<\/td>\nRecurse into entire pattern<\/td>\n<\/tr>\n
(?Y)<\/td>\nRecurse into numbered group Y<\/td>\n<\/tr>\n
(?&Y)<\/td>\nRecurse into named group Y<\/td>\n<\/tr>\n
\\g{Y}<\/td>\nMatch the named or numbered group Y<\/td>\n<\/tr>\n
\\g<Y><\/td>\nRecurse into named or numbered group Y<\/td>\n<\/tr>\n
(?#…)<\/td>\nComment<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/td>\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Regular Expression Character Classes<\/th>\n<\/tr>\n
[ab-d]<\/td>\nOne character of: a, b, c, d<\/td>\n<\/tr>\n
[^ab-d]<\/td>\nOne character except: a, b, c, d<\/td>\n<\/tr>\n
[\\b]<\/td>\nBackspace character<\/td>\n<\/tr>\n
\\d<\/td>\nOne digit<\/td>\n<\/tr>\n
\\D<\/td>\nOne non-digit<\/td>\n<\/tr>\n
\\s<\/td>\nOne whitespace<\/td>\n<\/tr>\n
\\S<\/td>\nOne non-whitespace<\/td>\n<\/tr>\n
\\w<\/td>\nOne word character<\/td>\n<\/tr>\n
\\W<\/td>\nOne non-word character<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Regular Expression Assertions<\/th>\n<\/tr>\n
^<\/td>\nStart of string<\/td>\n<\/tr>\n
\\A<\/td>\nStart of string, ignores m flag<\/td>\n<\/tr>\n
$<\/td>\nEnd of string<\/td>\n<\/tr>\n
\\Z<\/td>\nEnd of string, ignores m flag<\/td>\n<\/tr>\n
\\b<\/td>\nWord boundary<\/td>\n<\/tr>\n
\\B<\/td>\nNon-word boundary<\/td>\n<\/tr>\n
\\G<\/td>\nStart of match<\/td>\n<\/tr>\n
(?=…)<\/td>\nPositive lookahead<\/td>\n<\/tr>\n
(?!…)<\/td>\nNegative lookahead<\/td>\n<\/tr>\n
(?<=…)<\/td>\nPositive lookbehind<\/td>\n<\/tr>\n
(?<!…)<\/td>\nNegative lookbehind<\/td>\n<\/tr>\n
(?()|)<\/td>\nConditional<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n\n
Regular Expression Escapes<\/th>\n<\/tr>\n
\\Q..\\E<\/td>\nRemove special meaning<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/td>\n\n\n\n\n\n\n\n\n\n\n\n
Regular Expression Flags<\/th>\n<\/tr>\n
i<\/td>\nIgnore case<\/td>\n<\/tr>\n
m<\/td>\n^ and $ match start and end of line<\/td>\n<\/tr>\n
s<\/td>\n. matches newline as well<\/td>\n<\/tr>\n
x<\/td>\nAllow spaces and comments<\/td>\n<\/tr>\n
J<\/td>\nDuplicate group names allowed<\/td>\n<\/tr>\n
U<\/td>\nUngreedy quantifiers<\/td>\n<\/tr>\n
(?iLmsux)<\/td>\nSet flags within regex<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n\n\n\n\n\n\n\n\n
Regular Expression Special Characters<\/th>\n<\/tr>\n
\\n<\/td>\nNewline<\/td>\n<\/tr>\n
\\r<\/td>\nCarriage return<\/td>\n<\/tr>\n
\\t<\/td>\nTab<\/td>\n<\/tr>\n
\\0<\/td>\nNull character<\/td>\n<\/tr>\n
\\YYY<\/td>\nOctal character YYY<\/td>\n<\/tr>\n
\\xYY<\/td>\nHexadecimal character YY<\/td>\n<\/tr>\n
\\x{YY}<\/td>\nHexadecimeal character YY<\/td>\n<\/tr>\n
\\cY<\/td>\nControl character Y<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Regular Expression Posix Classes<\/th>\n<\/tr>\n
[:alnum:]<\/td>\nLetters and digits<\/td>\n<\/tr>\n
[:alpha:]<\/td>\nLetters<\/td>\n<\/tr>\n
[:ascii:]<\/td>\nAscii codes 0 – 127<\/td>\n<\/tr>\n
[:blank:]<\/td>\nSpace or tab only<\/td>\n<\/tr>\n
[:cntrl:]<\/td>\nControl characters<\/td>\n<\/tr>\n
[:digit:]<\/td>\nDecimal digits<\/td>\n<\/tr>\n
[:graph:]<\/td>\nVisible characters, except space<\/td>\n<\/tr>\n
[:lower:]<\/td>\nLowercase letters<\/td>\n<\/tr>\n
[:print:]<\/td>\nVisible characters<\/td>\n<\/tr>\n
[:punct:]<\/td>\nVisible punctuation characters<\/td>\n<\/tr>\n
[:space:]<\/td>\nWhitespace<\/td>\n<\/tr>\n
[:upper:]<\/td>\nUppercase letters<\/td>\n<\/tr>\n
[:word:]<\/td>\nWord characters<\/td>\n<\/tr>\n
[:xdigit:]<\/td>\nHexadecimal digits<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

New to Debuggex? Check out the\u00a0regex tester<\/a>!<\/span><\/p>\n

PCRE Regex Cheatsheet<\/h2>\n

<\/span><\/p>\n

\n\n\n\n
\n\n\n\n\n\n\n\n\n\n
Regular Expression Basics<\/th>\n<\/tr>\n
.<\/td>\nAny character except newline<\/td>\n<\/tr>\n
a<\/td>\nThe character a<\/td>\n<\/tr>\n
ab<\/td>\nThe string ab<\/td>\n<\/tr>\n
a|b<\/td>\na or b<\/td>\n<\/tr>\n
a*<\/td>\n0 or more a’s<\/td>\n<\/tr>\n
\\<\/td>\nEscapes a special character<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n\n\n\n\n\n\n\n
Regular Expression Quantifiers<\/th>\n<\/tr>\n
*<\/td>\n0 or more<\/td>\n<\/tr>\n
+<\/td>\n1 or more<\/td>\n<\/tr>\n
?<\/td>\n0 or 1<\/td>\n<\/tr>\n
{2}<\/td>\nExactly 2<\/td>\n<\/tr>\n
{2, 5}<\/td>\nBetween 2 and 5<\/td>\n<\/tr>\n
{2,}<\/td>\n2 or more<\/td>\n<\/tr>\n
Default is greedy. Append ? for reluctant.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Regular Expression Groups<\/th>\n<\/tr>\n
(…)<\/td>\nCapturing group<\/td>\n<\/tr>\n
(?P<Y>…)<\/td>\nCapturing group named Y<\/td>\n<\/tr>\n
(?:…)<\/td>\nNon-capturing group<\/td>\n<\/tr>\n
(?>…)<\/td>\nAtomic group<\/td>\n<\/tr>\n
(?|…)<\/td>\nDuplicate group numbers<\/td>\n<\/tr>\n
\\Y<\/td>\nMatch the Y’th captured group<\/td>\n<\/tr>\n
(?P=Y)<\/td>\nMatch the named group Y<\/td>\n<\/tr>\n
(?R)<\/td>\nRecurse into entire pattern<\/td>\n<\/tr>\n
(?Y)<\/td>\nRecurse into numbered group Y<\/td>\n<\/tr>\n
(?&Y)<\/td>\nRecurse into named group Y<\/td>\n<\/tr>\n
\\g{Y}<\/td>\nMatch the named or numbered group Y<\/td>\n<\/tr>\n
\\g<Y><\/td>\nRecurse into named or numbered group Y<\/td>\n<\/tr>\n
(?#…)<\/td>\nComment<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/td>\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Regular Expression Character Classes<\/th>\n<\/tr>\n
[ab-d]<\/td>\nOne character of: a, b, c, d<\/td>\n<\/tr>\n
[^ab-d]<\/td>\nOne character except: a, b, c, d<\/td>\n<\/tr>\n
[\\b]<\/td>\nBackspace character<\/td>\n<\/tr>\n
\\d<\/td>\nOne digit<\/td>\n<\/tr>\n
\\D<\/td>\nOne non-digit<\/td>\n<\/tr>\n
\\s<\/td>\nOne whitespace<\/td>\n<\/tr>\n
\\S<\/td>\nOne non-whitespace<\/td>\n<\/tr>\n
\\w<\/td>\nOne word character<\/td>\n<\/tr>\n
\\W<\/td>\nOne non-word character<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Regular Expression Assertions<\/th>\n<\/tr>\n
^<\/td>\nStart of string<\/td>\n<\/tr>\n
\\A<\/td>\nStart of string, ignores m flag<\/td>\n<\/tr>\n
$<\/td>\nEnd of string<\/td>\n<\/tr>\n
\\Z<\/td>\nEnd of string, ignores m flag<\/td>\n<\/tr>\n
\\b<\/td>\nWord boundary<\/td>\n<\/tr>\n
\\B<\/td>\nNon-word boundary<\/td>\n<\/tr>\n
\\G<\/td>\nStart of match<\/td>\n<\/tr>\n
(?=…)<\/td>\nPositive lookahead<\/td>\n<\/tr>\n
(?!…)<\/td>\nNegative lookahead<\/td>\n<\/tr>\n
(?<=…)<\/td>\nPositive lookbehind<\/td>\n<\/tr>\n
(?<!…)<\/td>\nNegative lookbehind<\/td>\n<\/tr>\n
(?()|)<\/td>\nConditional<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n\n
Regular Expression Escapes<\/th>\n<\/tr>\n
\\Q..\\E<\/td>\nRemove special meaning<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/td>\n\n\n\n\n\n\n\n\n\n\n\n
Regular Expression Flags<\/th>\n<\/tr>\n
i<\/td>\nIgnore case<\/td>\n<\/tr>\n
m<\/td>\n^ and $ match start and end of line<\/td>\n<\/tr>\n
s<\/td>\n. matches newline as well<\/td>\n<\/tr>\n
x<\/td>\nAllow spaces and comments<\/td>\n<\/tr>\n
J<\/td>\nDuplicate group names allowed<\/td>\n<\/tr>\n
U<\/td>\nUngreedy quantifiers<\/td>\n<\/tr>\n
(?iLmsux)<\/td>\nSet flags within regex<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n\n\n\n\n\n\n\n\n
Regular Expression Special Characters<\/th>\n<\/tr>\n
\\n<\/td>\nNewline<\/td>\n<\/tr>\n
\\r<\/td>\nCarriage return<\/td>\n<\/tr>\n
\\t<\/td>\nTab<\/td>\n<\/tr>\n
\\0<\/td>\nNull character<\/td>\n<\/tr>\n
\\YYY<\/td>\nOctal character YYY<\/td>\n<\/tr>\n
\\xYY<\/td>\nHexadecimal character YY<\/td>\n<\/tr>\n
\\x{YY}<\/td>\nHexadecimeal character YY<\/td>\n<\/tr>\n
\\cY<\/td>\nControl character Y<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Regular Expression Posix Classes<\/th>\n<\/tr>\n
[:alnum:]<\/td>\nLetters and digits<\/td>\n<\/tr>\n
[:alpha:]<\/td>\nLetters<\/td>\n<\/tr>\n
[:ascii:]<\/td>\nAscii codes 0 – 127<\/td>\n<\/tr>\n
[:blank:]<\/td>\nSpace or tab only<\/td>\n<\/tr>\n
[:cntrl:]<\/td>\nControl characters<\/td>\n<\/tr>\n
[:digit:]<\/td>\nDecimal digits<\/td>\n<\/tr>\n
[:graph:]<\/td>\nVisible characters, except space<\/td>\n<\/tr>\n
[:lower:]<\/td>\nLowercase letters<\/td>\n<\/tr>\n
[:print:]<\/td>\nVisible characters<\/td>\n<\/tr>\n
[:punct:]<\/td>\nVisible punctuation characters<\/td>\n<\/tr>\n
[:space:]<\/td>\nWhitespace<\/td>\n<\/tr>\n
[:upper:]<\/td>\nUppercase letters<\/td>\n<\/tr>\n
[:word:]<\/td>\nWord characters<\/td>\n<\/tr>\n
[:xdigit:]<\/td>\nHexadecimal digits<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

 <\/p>\n

Details: https:\/\/www.google.com.vn\/search?q=pcre+regex&oq=pcre+&aqs=chrome.3.69i57j69i60j0l4.2639j0j7&client=ubuntu&sourceid=chrome&ie=UTF-8<\/p>\n","protected":false},"excerpt":{"rendered":"

PCRE Regex Cheatsheet Regular Expression Basics . Any character except newline a The character a ab The string ab a|b […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[29,30,31,32,33,25,16,19,20,26,27,28,21,6,8],"tags":[],"class_list":["post-1266","post","type-post","status-publish","format-standard","hentry","category-ccie-rs","category-ccna","category-ccnp-route","category-ccnp-switch","category-ccnp-tshoot","category-cisco","category-courses","category-issues","category-issues-system","category-jncia","category-jncie","category-jncip","category-juniper","category-networking","category-system"],"_links":{"self":[{"href":"https:\/\/kb.lagonet.vn\/index.php?rest_route=\/wp\/v2\/posts\/1266","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kb.lagonet.vn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kb.lagonet.vn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kb.lagonet.vn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/kb.lagonet.vn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1266"}],"version-history":[{"count":0,"href":"https:\/\/kb.lagonet.vn\/index.php?rest_route=\/wp\/v2\/posts\/1266\/revisions"}],"wp:attachment":[{"href":"https:\/\/kb.lagonet.vn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1266"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kb.lagonet.vn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1266"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kb.lagonet.vn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1266"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}