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
  • Match everything enclosed
    (?:...)
  • Capture everything enclosed
    (...)
  • 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

/
/
gmi

Test String

Code Generator

Language

Generated Code

// include the latest version of the regex crate in your Cargo.toml extern crate regex; use regex::Regex; fn main() { let regex = Regex::new(r"(?mi)^(?<date>\d{4}-\d{2}-\d{2})\s*(?<time>\d{2}:\d{2}:\d{2}:\d{3})\s*\[\s*(?<level>\w*)\s*(?<module>.*?)\s*\]\s*(?<message>.*)$").unwrap(); let string = "2021-09-27 09:28:25:778 [ debug nextcloud.sync.database ] [ OCC::SyncJournalDb::tableColumns ]: Columns in the current journal: QVector(\"path\", \"chunk\", \"transferid\", \"errorcount\", \"size\", \"modtime\", \"contentChecksum\") 2021-09-27 09:28:25:778 [ debug nextcloud.sync.database.sql ] [ OCC::SqlQuery::exec ]: SQL exec \"PRAGMA table_info('conflicts');\" 2021-09-27 09:28:25:778 [ debug nextcloud.sync.database ] [ OCC::SyncJournalDb::tableColumns ]: Columns in the current journal: QVector(\"path\", \"baseFileId\", \"baseEtag\", \"baseModtime\", \"basePath\") 2021-09-27 09:28:25:778 [ debug nextcloud.sync.database.sql ] [ OCC::SqlQuery::exec ]: SQL exec \"CREATE INDEX IF NOT EXISTS metadata_e2e_id ON metadata(e2eMangledName);\" 2021-09-27 09:28:25:778 [ debug nextcloud.sync.database.sql ] [ OCC::SqlQuery::exec ]: Last exec affected 0 rows. 2021-09-27 09:28:25:778 [ debug nextcloud.sync.database ] [ OCC::SyncJournalDb::commitInternal ]: Transaction commit \"update database structure: add e2eMangledName index\" and starting new transaction 2021-09-27 09:28:25:778 [ debug nextcloud.sync.database.sql ] [ OCC::SqlQuery::exec ]: SQL exec \"PRAGMA table_info('blacklist');\" 2021-09-27 09:28:25:778 [ debug nextcloud.sync.database ] [ OCC::SyncJournalDb::tableColumns ]: Columns in the current journal: QVector(\"path\", \"lastTryEtag\", \"lastTryModtime\", \"retrycount\", \"errorstring\", \"lastTryTime\", \"ignoreDuration\", \"renameTarget\", \"errorCategory\", \"requestId\") 2021-09-27 09:28:25:778 [ debug nextcloud.sync.database.sql ] [ OCC::SqlQuery::exec ]: SQL exec \"CREATE INDEX IF NOT EXISTS blacklist_index ON blacklist(path collate nocase);\" 2021-09-27 09:28:25:778 [ debug nextcloud.sync.database.sql ] [ OCC::SqlQuery::exec ]: Last exec affected 0 rows. 2021-09-27 09:28:25:778 [ debug nextcloud.sync.database ] [ OCC::SyncJournalDb::commitInternal ]: Transaction commit \"checkConnect End\" 2021-09-27 09:28:25:778 [ debug nextcloud.sync.database.sql ] [ OCC::SqlQuery::exec ]: SQL exec \"SELECT COUNT(*) FROM metadata\" 2021-09-27 09:28:25:794 [ info nextcloud.gui.folder.manager ]: Adding folder to Folder Map OCC::Folder(0x2677fdf3ee0) \"1\" 2021-09-27 09:28:25:795 [ info nextcloud.gui.folder.manager ]: Schedule folder \"1\" to sync! 2021-09-27 09:28:25:795 [ info nextcloud.gui.folder.manager ]: Folder is not ready to sync, not scheduled! 2021-09-27 09:28:25:797 [ info nextcloud.gui.application ]: Sync state changed for folder \"\" : \"Not yet Started\" 2021-09-27 09:28:25:797 [ info nextcloud.sync.clientproxy ]: Set proxy configuration to use the preferred system proxy for http tcp connections 2021-09-27 09:28:25:801 [ debug nextcloud.gui.updater ] [ OCC::Updater::create ]: QUrl(\"https://updates.nextcloud.org/client/?version=3.3.4.20210920&platform=win32&osRelease=windows&osVersion=server2016&kernelVersion=10.0.17763&oem=Nextcloud&buildArch=x86_64&currentArch=x86_64&versionsuffix=stable-Win64&updatesegment=43&msi=true\") 2021-09-27 09:28:26:533 [ info nextcloud.sync.credentials.webflow ]: Fetch from keychain! 2021-09-27 09:28:26:536 [ info nextcloud.gui.folder.navigationpane ]: Explorer Cloud storage provider: saving path \"\" to CLSID \"{5cefc208-e391-444c-af93-61c636da9853}\" 2021-09-27 09:28:26:537 [ info nextcloud.gui.socketapi ]: New connection QLocalSocket(0x267027e4570) 2021-09-27 09:28:26:538 [ warning nextcloud.sync.credentials.keychainchunk ]: Unable to read \"Nextcloud_clientCertificatePEM:0\" chunk \"0\" \"Password entry not found\" 2021-09-27 09:28:26:538 [ warning nextcloud.sync.credentials.keychainchunk ]: Unable to read \"Nextcloud_clientKeyPEM\" chunk \"0\" \"Password entry not found\" 2021-09-27 09:28:26:538 [ warning nextcloud.sync.credentials.webflow ]: Unable to read client key \"Password entry not found\" 2021-09-27 09:28:26:538 [ warning nextcloud.sync.credentials.keychainchunk ]: Unable to read \"Nextcloud_su_mssrv01_clientCaCertificatePEM0\" chunk \"0\" \"Password entry not found\" 2021-09-27 09:28:26:538 [ warning nextcloud.sync.credentials.webflow ]: Unable to read client CA cert slot \"0\" \"Password entry not found\" 2021-09-27 09:28:26:538 [ debug nextcloud.sync.account ] [ OCC::Account::slotCredentialsFetched ]: User id already fetched. 2021-09-27 09:28:26:539 [ info nextcloud.gui.account.state ]: Fetched credentials for \"\" attempting to connect 2021-09-27 09:28:26:539 [ debug nextcloud.sync.account ] [ OCC::Account::resetNetworkAccessManager ]: Resetting QNAM 2021-09-27 09:28:26:539 [ info nextcloud.sync.credentials.webflow ]: Get QNAM 2021-09-27 09:28:26:539 [ debug nextcloud.sync.connectionvalidator ] [ OCC::ConnectionValidator::checkServerAndAuth ]: Checking server and authentication 2021-09-27 09:28:26:539 [ debug nextcloud.sync.connectionvalidator ] [ OCC::ConnectionValidator::checkServerAndAuth ]: Trying to look up system proxy 2021-09-27 09:28:26:540 [ info nextcloud.sync.connectionvalidator ]: No system proxy set by OS 2021-09-27 09:28:26:541 [ info nextcloud.sync.accessmanager ]: 2 \"\" \"\" has X-Request-ID \"75765e8e-2b52-4dd9-b67b-62b450feafdc\" 2021-09-27 09:28:26:541 [ debug nextcloud.sync.cookiejar ] [ OCC::CookieJar::cookiesForUrl ]: QUrl(\"\") requests: (QNetworkCookie(\"nc_sameSiteCookielax=true; secure; HttpOnly; expires=Fri, 31-Dec-2100 23:59:59 GMT), QNetworkCookie(\"nc_sameSiteCookiestrict=true; secure; HttpOnly; expires=Fri, 31-Dec-2100 23:59:59 GMT)) 2021-09-27 09:28:26:541 [ info nextcloud.sync.networkjob ]: OCC::CheckServerJob created for \"\" + \"status.php\" \"OCC::ConnectionValidator\" 2021-09-27 09:28:26:795 [ debug nextcloud.gui.folderwatcher ] [ OCC::FolderWatcher::pathIsIgnored ]: * Ignoring file \"D:/Shared/NextcloudMirror/.owncloudsync.log\" 2021-09-27 09:28:28:826 [ info nextcloud.gui.updater ]: Checking for available update 2021-09-27 09:28:28:826 [ info nextcloud.sync.accessmanager ]: 2 \"\" \"https://updates.nextcloud.org/client/?version=3.3.4.20210920&platform=win32&osRelease=windows&osVersion=server2016&kernelVersion=10.0.17763&oem=Nextcloud&buildArch=x86_64&currentArch=x86_64&versionsuffix=stable-Win64&updatesegment=43&msi=true\" has X-Request-ID \"2fbd3d8d-a4e6-486f-b0f7-dbd441225cd3\" 2021-09-27 09:28:28:826 [ debug nextcloud.sync.cookiejar ] [ OCC::CookieJar::cookiesForUrl ]: QUrl(\"https://updates.nextcloud.org/client/?version=3.3.4.20210920&platform=win32&osRelease=windows&osVersion=server2016&kernelVersion=10.0.17763&oem=Nextcloud&buildArch=x86_64&currentArch=x86_64&versionsuffix=stable-Win64&updatesegment=43&msi=true\") requests: () 2021-09-27 09:28:29:638 [ info nextcloud.sync.credentials.webflow ]: request finished"; // result will be an iterator over tuples containing the start and end indices for each match in the string let result = regex.captures_iter(string); for mat in result { println!("{:?}", mat); } }

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 Rust, please visit: https://docs.rs/regex/latest/regex/