Regular Expressions 101

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An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression
No Match

/
/
g

Test String

Code Generator

Language

Generated Code

const regex = /(?<opening>\b(?<montage>[a-zA-Z]:[\/\\])|[\/\\][\/\\](?<!http:\/\/)(?<!https:\/\/)(?>[?.][\/\\](?:[^\/\\<>:"|?\n\r ]+[\/\\])?(?&montage)?|(?!(?&montage)))|%\w+%[\/\\]?)(?:[^\/\\<>:"|?\n\r ,'][^\/\\<>:"|?\n\r]*(?<![ ,'])[\/\\])*(?:(?=[^\/\\<>:"'|?\n\r;, ])(?:(?:[^\/\\<>:"|?\n\r;, .](?: (?=[\w\-]))?(?:\*(?!= ))?(?!(?&montage)))+)?(?:\.\w+)*)|(?:'(?&opening)(?=.*'\W|.*'$)(?:[^\/\\<>:'"|?\n\r]+(?:'(?=\w))?[\/\\]?)*')|"(?&opening)(?=.*")(?:[^\/\\<>:"|?\n\r]+[\/\\]?)*"/g; // Alternative syntax using RegExp constructor // const regex = new RegExp('(?<opening>\\b(?<montage>[a-zA-Z]:[\\\/\\\\])|[\\\/\\\\][\\\/\\\\](?<!http:\\\/\\\/)(?<!https:\\\/\\\/)(?>[?.][\\\/\\\\](?:[^\\\/\\\\<>:"|?\\n\\r ]+[\\\/\\\\])?(?&montage)?|(?!(?&montage)))|%\\w+%[\\\/\\\\]?)(?:[^\\\/\\\\<>:"|?\\n\\r ,\'][^\\\/\\\\<>:"|?\\n\\r]*(?<![ ,\'])[\\\/\\\\])*(?:(?=[^\\\/\\\\<>:"\'|?\\n\\r;, ])(?:(?:[^\\\/\\\\<>:"|?\\n\\r;, .](?: (?=[\\w\\-]))?(?:\\*(?!= ))?(?!(?&montage)))+)?(?:\\.\\w+)*)|(?:\'(?&opening)(?=.*\'\\W|.*\'$)(?:[^\\\/\\\\<>:\'"|?\\n\\r]+(?:\'(?=\\w))?[\\\/\\\\]?)*\')|"(?&opening)(?=.*")(?:[^\\\/\\\\<>:"|?\\n\\r]+[\\\/\\\\]?)*"', 'g') const str = `THIS IS SINGLE LINE VERSION to understand and edit it, go https://regex101.com/r/7o2fyy C:/testOk\\dot.Dirname/.nameFileBeginByDot first space after a dot in file name stop the match C:/testOk\\_.._AsDirName/../file name.ext1.ext2 first space after a dot stop the match start text don't match C:/testOk\\lastDir Or FileName WithDouble..dot stop the match C:/testOk\\lastDir Or FileName dot ended. stop the match like an end sentence. So, a last name with a space after a dot is not catch C:/testOk\\LastNameIs/DirName C:/testOk\\2Paths_ _separated/f.ext space after extention stop match C:/testOK\\Last_/_isNotmatched/fgfj.gjjb/uhloext/ and [ ,'] after '\\' stop match \\\\127.0.0.1/this', 'isOkInMidDirName\\butSimple',' stop match in last DirName or FileName \\\\.\\c:/this exotic path begining work\\and\\ space after '\\' stop the match \\\\?\\c:/this exotic path begining work too\\and \\space before '\\' stop the match too \\\\testOk/this' - 'is ok in dirName/and - in lastName.ext i:/dir/fileName with a .space before dot stop the match \\\\?\\server1\\e:\\utilities\\\\filecomparer\\ this double \\\\ is interpretated as new path @"c:\\testOk\\double quote character is more permissive/ '' , ; .txt, .ext2", @"\\\\127.0.0.1\\c\$\\temp\\t'est-file.txt, if end double quote is missing, we use unquote match @"\\c:\\LOCALHOST\\c\$\\ thisIsNotMatched" "temp\\test-file.txt", quoted path must have a right opening to be matched @'\\\\.\\c:\\temp\\te'st-file.txt' simple quoted is ok 'c:\\simpleQuoteInsideStill'Match\\but' stopMatch if next is space character, 'c:\\simpleQuoteInsideStill'Match\\but\\'stopMatch if is fisrt character after \\ 'c:\\simpleQuoteInsideStill'Match\\but''stopMatch if he is double @"\\\\?\\c:\\te ' mp\\est-file.txt", @"\\\\.\\UNC\\LOCALHOST\\c\$\\temp\\test-file.txt", @"\\\\127.0.0.1\\c\$\\temp\\test-file.txt" /\\serverName\\mix/and\\still match" double quote character stop match \\\\\\IfMoreThan2_\\_we take only the 2 lasts.ext first space after ext stop the match /testNotMatch/html /testNotMatch.html testNotMatch.html // -> this simple // or \\\\ is not matched, but this //isMatched ! / -> this simple / is not matched, and this /notMatchedToo b-renice\\sauvegardes\\B-HIER\\GEO\\Geo_NetAct_Atoll_Planet\\UR_Est\\Custom Data" "b-renice\\sauvegardes\\B-HIER\\GEO\\Geo_NetAct_Atoll_Planet\\UR_Est\\Custom Data" "\\\\b-renice\\sauvegardes\\B-HIER\\GEO\\Geo_NetAct_Atoll_Planet\\UR_Est\\Custom Data" error Message test: --------------------------- Tentative d'accès à C:\\Users\\tpgz4017\\App - Data\\Local\\Temp\\tempShapeFile_CrossWave Calibration Zones - Atoll CrossWave Model.shx après sa fin. --------------------------- local url path : file://C:/Users/Downloads/20220516_32289275_1049383.pdf urlPath : file://p-eco2.rd.fr/vol_H0037_01\$/599/livraison/20220516_32289275_1049383.pdf c:\\temp\\test-file.txt", \\\\127.0.0.1\\c\$\\temp\\test-file.txt", \\\\LOCALHOST\\c\$\\ temp\\test-file.txt", \\\\LOCALHOST\\c\$ \\temp\\test-file.txt", \\\\.\\c:\\temp\\t\\est-file.txt", \\\\?\\c:\\temp\\test-file.txt", \\\\.\\UNC\\LOCALHOST\\c\$\\temp\\test-file.txt", \\\\?\\UNC\\ServerName\\ temp\\test-file.txt", \\\\127.0.0.1\\c\$\\temp\\test -file.txt" error Message test: Site0 / 3: - Warning . See log file 'C:\\ProgramData\\InfoVista\\Planet 7.4\\7.4\\RPE\\Log\\Plugins\\Universal_Model_masked\\log_Universal_Model.txt' for details C:/test\\gvk.hv/fgfj.gjjb/uhloext : some random text \\\\b-renice\\sauvegardes\\B-HIER\\GEO\\Geo_NetAct_Atoll_Planet\\UR_Est\\Polygon\\Haguenau\\Building\\Haguenau hgtfhyt "C:/te-st.html" "C:/te-st.html" gd"dhbcsk "C:/te/dsst.ikpo fdsf "C:\\test" "C:// test.html" gd "//te s t/e, llo.html C:/test\\f/uhlo/. C://te?st.html b-renice\\sauvegardes\\B-HIER\\GEO\\Geo_NetAct_Atoll_Planet\\UR_Est\\Custom Data" ; dfsdf "\\\\b-renice\\sauvegardes\\B-HIER\\GEO\\Geo_NetAct_Atoll_Planet\\UR_Est\\Custom Data" ; dfsdf "\\\\ "\\\\b-renice\\sauvegardes\\B-HIER\\GEO\\Geo_NetAct_Atoll_Planet\\UR_Est\\Custom Data"Haguenau_Building.tab : Data format of \\\\b-renice\\sauvegardes\\B-HIER\\GEO\\Geo_NetAct_Atoll_Planet\\UR_Est\\Polygon\\Haguenau\\Building\\Haguenau Building.* C: is invalid Haguenau_Building.tab : Data format of \\\\b-renice\\sauvegardes\\B-HIER\\GEO\\Geo NetAct Atoll_Planet\\UR_Est\\Polygon\\Haguenau\\Building\\Haguenau Building.TAB, is invalid Haguenau_Building.tab : Data format of \\\\b-renice\\sauvegardes\\B-HIER\\GEO\\Geo_NetAct_Atoll_Planet\\UR_Est\\Polygon\\Haguenau\\Building\\Haguenau Buildi*.*ng.*, is invalid C:/test/../hjgbkl C:/test/../hjgbkl.gfgdfgrdgfdgr C:/test/../hjgbkl C:/test.html C://test/ .h/hel,lo.html//test/./hello.html C:/test//hello.html //test //hello.html /test "%tmp%/fsdfs" %tmp%/fsdfs ERROR 8/31/2021 - 6:45:39 PM HighResClutter .RasterFile : \\\\b-ren ice\\sauv egardes\\B-HIER\\GEO%dsq%\\NewJersey_NewYork\\DTM\\DTM\\CENTRAL_JERSE..Y_New_York_2 m_Z18N_0_DTM_02_06.bil : Le fichier spécifié est introuvable. \\\\b-ren ice\\sauv egardes\\..\\B-HIER\\GEO\\NewJersey_NewYork\\DTM\\DTM\\CENTRAL_JERSE..Y_New_York_2 m_Z18N_0_DTM_02_06.bil C:\\b-ren ice\\sauv egardes\\B-HIER\\GEO\\NewJersey_NewYork\\DTM\\DTM\\CENTRAL_JERSE..Y_New_York_2 m_Z18N_0_DTM_02_06.bil \\\\b-ren ice\\sauv egardes\\B-HIER\\GEO\\NewJersey_NewYork\\DTM\\DTM\\CENTRAL_JER SE.Y_New_York_2 m_Z18N_0_DTM_02_06.bil. //test.html \\\\10.1.1.107 //10.1.1.107/test.html //10.1.1.107/te st/hello.html //10.1.1.107/test/hello //test/hello.txt //test/hello.txt. \\\\.\\UNC\\Server\\Share\\Test\\Foo.txt \\\\?\\UNC\\Server\\Share\\Test\\Foo.txt Pour les chemins UNC de périphérique, la partie serveur/partage forme le volume. Par exemple, dans \\\\?\\server1\\e:\\utilities\\filecomparer\\ , la partie serveur/partage est server1\\utilities . Ceci est important quand '\\\\127.0.0.1\\c\$\\temp\\test-fi'le.txt'`; // Reset `lastIndex` if this regex is defined globally // regex.lastIndex = 0; let m; while ((m = regex.exec(str)) !== null) { // This is necessary to avoid infinite loops with zero-width matches if (m.index === regex.lastIndex) { regex.lastIndex++; } // The result can be accessed through the `m`-variable. m.forEach((match, groupIndex) => { console.log(`Found match, group ${groupIndex}: ${match}`); }); }

Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions