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

/
/
igm

Test String

Code Generator

Language

Generated Code

import Foundation let pattern = #"\b(^(http|https|wss|ws|ftp|ftps):\/\/127[.](?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)[.](?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)[.](?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)|^(http|https|wss|ws|ftp|ftps):\/\/0.0.0.0|^(http|https|wss|ws|ftp|ftps):\/\/(10)([.](25[0-5]|2[0-4][0-9]|1[0-9]{1,2}|[0-9]{1,2})){3}|^(http|https|wss|ws|ftp|ftps):\/\/localhost|^(http|https|wss|ws|ftp|ftps):\/\/172[.](0?16|0?17|0?18|0?19|0?20|0?21|0?22|0?23|0?24|0?25|0?26|0?27|0?28|0?29|0?30|0?31)[.](?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)[.](?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)|^(http|https|wss|ws|ftp|ftps):\/\/192[.]168[.](?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)[.](?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)|^(http|https|wss|ws|ftp|ftps):\/\/169[.]254[.](?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)[.](?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))(?:\/([789]|1?[0-9]{2}))?\b"# let regex = try! NSRegularExpression(pattern: pattern, options: [.anchorsMatchLines, .caseInsensitive]) let testString = ##""" # loopback http://127.0.0.0:80 https://127.0.0.0000 # only three digits supported here # 0.0.0.0 Day http://0.0.0.0 ws://0.0.0.0 # Localhost http://localhost:25 https://localhost:8080 HTTP://LoCALhosT:99 # Case insensitive ws://localhost:7777 wss://LOCALHOST:9200 https://google.com/blah/localhost/ # This should not alert # Web Sockets ws://localhost:2121/sockjs-node wss://localhost:5882/ # FTP ftp://192.168.0.1 ftps://127.0.0.1 ftps://localhost # A (/8 CIDR) wss://10.0.0.1/10 ws://10.255.22.33 # B (/12 CIDR) http://172.17.100.155/32 # 172.16.0.0 to 172.31.255.255 http://172.15.1.1 # This should not fire http://172.32.1.1 # This should not fire # C (/16 CIDR) https://192.168.1.1/random/path wss://192.168.1.255 http://192.168.9.9 # IPv6 http://fc00:833e:d648:f196:5c6c:1d9a:a14b:0d59 # Private IPv6 wss://fc01:67e5::6a66:34a7 ftp://FC02:5fcf:e093:bb10:ce77:b5c9::/112 http://fc03:49bd:b7c1:5685:fa0a:87e9::2/128 ws://fc04:::2 hmpf http://0de9:b022:883f:2c3c:7dba:a184:7576:4531 # public IP addresses https://04e4:e53b:0c2f:2990:27ad:0464:6dd3:b6b3 wss://0319:3b4a:546e:d480:4814:f885:3396:bba2 ws://5394:03f5:606f:273e:e343:d94a:610a:3f2e ftp://63cd:ad1f:7ffb:62c7:cc17:6e20:9b59:2f7d # IPV6 with brackets http://[::1] # Private IPv6 http://[fc00:833e:d648:f196:5c6c:1d9a:a14b:0d59] wss://[fc01:67e5::6a66:34a7] ftp://[FC02:5fcf:e093:bb10:ce77:b5c9::]/112 http://[fc03:49bd:b7c1:5685:fa0a:87e9::2]/128 ws://[fc04:::2] hmpf http://[0de9:b022:883f:2c3c:7dba:a184:7576:4531] # public IP addresses None of these should fire https://[04e4:e53b:0c2f:2990:27ad:0464:6dd3:b6b3] wss://[0319:3b4a:546e:d480:4814:f885:3396:bba2] ws://[5394:03f5:606f:273e:e343:d94a:610a:3f2e] ftp://[63cd:ad1f:7ffb:62c7:cc17:6e20:9b59:2f7d] # More "crap" should not fire ws://30.168.1.255.1 wss://127.1 https://192.168.1.256 http://-1.2.3.4 wss://1.1.1.1. ftp://3...3 wss://255.255.255.255 ftps://0.0.0.0 wss://1.1.1.01 https://10207287.fls.doubleclick.net/ # decimal vs. octal mix http://172.031.33.33 http://172.021.133.01 # octal - not supported here http://0254.0021.0062.0041 # Should not fire # link-local addresses IPv4 http://169.254.1.0 http://169.254.254.255 # link-local addresses IPv6 http://fe90:1234::/64 http://feaf:ffff::/128 http://febf:ffff:ffff:ffff:ffff:ffff:ffff:ffff """## 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