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

/
/
gm

Test String

Code Generator

Language

Generated Code

import Foundation let pattern = #"[\s'](?:MIMA01|mima01|ERROR\s+Thycotic\.AppCore\.Emailer2|RADIUS|Thycotic\.webapp\.Web\.usercontrols\.Login)[\s']"# let regex = try! NSRegularExpression(pattern: pattern, options: .anchorsMatchLines) let testString = #""" 2019-01-07 18:12:50,548 [57] INFO Thycotic.webapp.Web.usercontrols.Login (null) - Login attempt on node MIMA01 by user gdh failed: Login failed. 2019-01-07 17:39:29,450 [104] ERROR Thycotic.AppCore.Emailer2 (null) - An error occured while sending an email (async internal): to: *redacted* subject: [SecretServer] Password Reset Exception: Value cannot be null. Parameter name: context 2019-01-07 17:43:49,654 [107] ERROR Thycotic.AppCore.Emailer2 (null) - An error occured while sending an email (async internal): to: *redacted* subject: [SecretServer] Password Reset Exception: Value cannot be null. Parameter name: context 2019-01-07 17:43:58,123 [107] INFO Thycotic.webapp.Web.usercontrols.Login (null) - Login attempt on node MIMA01 by user flortx failed: Unable to find a user record from the information provided. 2019-01-07 17:44:30,592 [110] ERROR Thycotic.AppCore.Radius.RadiusAuthenticationProvider (null) - RadiusAuthenticationProvider.Authenticate. Unexpected response code: RadiusCode AccessReject. (Username: flort, Requesting server IP: *redacted*, RADIUS server: 127.0.0.1:1812). 2019-01-07 17:44:30,717 [110] ERROR Thycotic.webapp.Web.usercontrols.Login (null) - Attempt to do a RADIUS Two Factor login failed. Error Message: RADIUS Authentication Failed., ResponseCode: AccessReject, AuditUserError: TWO FACTOR ACCESS REJECTED (Domain: 'Local', Username: 'flort', RADIUS Server: '127.0.0.1:1812', Machine Name: 'MIMA01' Is From Access Challenge: False) 2019-01-07 17:44:30,763 [110] WARN Thycotic.webapp.Web.usercontrols.Login (null) - Two-Factor failed. Error:RADIUS Authentication Failed. AuditUserError: TWO FACTOR ACCESS REJECTED Domain: 'Local', Username: 'flort', RADIUS Server: '127.0.0.1:1812', Machine Name: 'MIMA01' Is From Access Challenge: False 2019-01-07 17:46:23,982 [87] INFO Thycotic.AppCore.KeepAliveMonitor (null) - Keeping endpoints alive 2019-01-07 22:15:21,727 [98] INFO Thycotic.AppCore.KeepAliveMonitor (null) - Keeping endpoints alive 2019-01-07 22:17:19,196 [63] INFO Thycotic.webapp.Web.usercontrols.Login (null) - Login attempt on node MIMA01 by user *redacted* failed: Login failed. 2019-01-07 22:20:54,899 [99] INFO Thycotic.webapp.Web.usercontrols.Login (null) - Login attempt on node MIMA01 by user *redacted* failed: Login failed. 2019-01-07 22:20:58,243 [63] INFO Thycotic.webapp.Web.usercontrols.Login (null) - Login attempt on node MIMA01 by user *redacted* failed: Login failed. 2019-01-07 22:21:02,024 [10] INFO Thycotic.webapp.Web.usercontrols.Login (null) - Login attempt on node MIMA01 by user *redacted* failed: Login failed. 2019-01-07 22:21:47,212 [59] INFO Thycotic.webapp.Web.usercontrols.Login (null) - Login attempt on node MIMA01 by user flortx failed: Unable to find a user record from the information provided. 2019-01-07 22:25:21,947 [62] INFO Thycotic.AppCore.KeepAliveMonitor (null) - Endpoint https://127.0.0.1/SecretServer/healthcheck.aspx?selfRun responded healthy in 80ms for 1/7/2019 2:25:21 PM(1/7/2019 10:25:21 PM) 2019-01-07 22:30:21,978 [92] INFO Thycotic.AppCore.KeepAliveMonitor (null) - Keeping endpoints alive """# let stringRange = NSRange(location: 0, length: testString.utf16.count) let matches = regex.matches(in: testString, range: stringRange) var result: [[String]] = [] for match in matches { var groups: [String] = [] for rangeIndex in 1 ..< match.numberOfRanges { let nsRange = match.range(at: rangeIndex) guard !NSEqualRanges(nsRange, NSMakeRange(NSNotFound, 0)) else { continue } let string = (testString as NSString).substring(with: nsRange) groups.append(string) } if !groups.isEmpty { result.append(groups) } } print(result)

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 Swift 5.2, please visit: https://developer.apple.com/documentation/foundation/nsregularexpression