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

using System; using System.Text.RegularExpressions; public class Example { public static void Main() { string pattern = @"^(?<vendor_date>\d{4}(?:\-\d\d){2} [^,]+,[^:]+):(?<vendor_level>[^:]+):(?<vendor_component>[^:]+):(?<vendor_message>[^\n\r]+)(?<vendor_details>(?(?=^\d{4}(?:\-\d\d){2})|[^\r])+)?"; string input = @"2019-10-14 11:07:08,727:DEBUG:certbot.cli:Var dry_run=True (set by user). 2019-10-14 11:07:08,727:DEBUG:certbot.cli:Var server={'dry_run', 'staging'} (set by user). 2019-10-14 11:07:08,727:DEBUG:certbot.cli:Var dry_run=True (set by user). 2019-10-14 11:07:08,728:DEBUG:certbot.cli:Var server={'dry_run', 'staging'} (set by user). 2019-10-14 11:07:08,728:DEBUG:certbot.cli:Var account={'server'} (set by user). 2019-10-14 11:07:08,757:INFO:certbot.renewal:Cert not due for renewal, but simulating renewal for dry run 2019-10-14 11:07:08,757:DEBUG:certbot.plugins.selection:Requested authenticator nginx and installer nginx 2019-10-14 11:07:10,881:DEBUG:certbot.plugins.selection:Single candidate plugin: * nginx Description: Nginx Web Server plugin Interfaces: IAuthenticator, IInstaller, IPlugin Entry point: nginx = certbot_nginx.configurator:NginxConfigurator Initialized: Prep: True 2019-10-14 11:07:10,888:DEBUG:certbot.plugins.selection:Single candidate plugin: * nginx Description: Nginx Web Server plugin Interfaces: IAuthenticator, IInstaller, IPlugin Entry point: nginx = certbot_nginx.configurator:NginxConfigurator Initialized: Prep: True 2019-10-14 11:07:10,889:DEBUG:certbot.plugins.selection:Selected authenticator and installer 2019-10-14 11:07:10,889:INFO:certbot.plugins.selection:Plugins selected: Authenticator nginx, Installer nginx 2019-10-14 11:07:10,902:DEBUG:certbot.main:Picked account: )>), only_return_existing=None, contact=('mailto:trol@yopmail.com',), agreement='https://letsencrypt.org/documents/LE-SA-v1.2-November-15-2017.pdf')), 019763ae9d0030f2ffa8f8cb689e7976, Meta(creation_dt=datetime.datetime(2018, 2, 27, 14, 17, 55, tzinfo=), creation_host='sd-99715.dedibox.fr'))> 2019-10-14 11:07:10,911:DEBUG:acme.client:Sending GET request to https://acme-staging-v02.api.letsencrypt.org/directory. 2019-10-14 11:07:10,998:DEBUG:requests.packages.urllib3.connectionpool:Starting new HTTPS connection (1): acme-staging-v02.api.letsencrypt.org 2019-10-14 11:07:14,617:DEBUG:requests.packages.urllib3.connectionpool:https://acme-staging-v02.api.letsencrypt.org:443 ""GET /directory HTTP/1.1"" 200 724 2019-10-14 11:07:14,619:DEBUG:acme.client:Received response: HTTP 200 Server: nginx Date: Mon, 14 Oct 2019 09:07:14 GMT Content-Type: application/json Content-Length: 724 Connection: keep-alive Cache-Control: public, max-age=0, no-cache X-Frame-Options: DENY Strict-Transport-Security: max-age=604800 { ""kRr68eKT_x4"": ""https://community.letsencrypt.org/t/adding-random-entries-to-the-directory/33417"", ""keyChange"": ""https://acme-staging-v02.api.letsencrypt.org/acme/key-change"", ""meta"": { ""caaIdentities"": [ ""letsencrypt.org"" ], ""termsOfService"": ""https://letsencrypt.org/documents/LE-SA-v1.2-November-15-2017.pdf"", ""website"": ""https://letsencrypt.org/docs/staging-environment/"" }, ""newAccount"": ""https://acme-staging-v02.api.letsencrypt.org/acme/new-acct"", ""newNonce"": ""https://acme-staging-v02.api.letsencrypt.org/acme/new-nonce"", ""newOrder"": ""https://acme-staging-v02.api.letsencrypt.org/acme/new-order"", ""revokeCert"": ""https://acme-staging-v02.api.letsencrypt.org/acme/revoke-cert"" } 2019-10-14 11:07:14,620:INFO:certbot.main:Renewing an existing certificate 2019-10-14 11:07:14,999:DEBUG:acme.client:Requesting fresh nonce 2019-10-14 11:07:15,006:DEBUG:acme.client:Sending HEAD request to https://acme-staging-v02.api.letsencrypt.org/acme/new-nonce. 2019-10-14 11:07:15,156:DEBUG:requests.packages.urllib3.connectionpool:https://acme-staging-v02.api.letsencrypt.org:443 ""HEAD /acme/new-nonce HTTP/1.1"" 200 0 2019-10-14 11:07:15,158:DEBUG:acme.client:Received response: HTTP 200 Server: nginx Date: Mon, 14 Oct 2019 09:07:15 GMT Connection: keep-alive Cache-Control: public, max-age=0, no-cache Link: https://acme-staging-v02.api.letsencrypt.org/directory;rel=""index"" Replay-Nonce: 0002fqXrdxZwV_xxxxx-xxxxxxxx-KdWhvOCtgFh5YNNVM X-Frame-Options: DENY Strict-Transport-Security: max-age=604800 2019-10-14 11:07:15,158:DEBUG:acme.client:Storing nonce: 0002fqXrdxZwV_xxxxx-xxxxxxxx-KdWhvOCtgFh5YNNVM 2019-10-14 11:07:15,160:DEBUG:acme.client:JWS payload: b'{\n ""identifiers"": [\n {\n ""type"": ""dns"",\n ""value"": ""site.tld""\n },\n {\n ""type"": ""dns"",\n ""value"": ""cdn-css. site.tld ""\n },\n {\n ""type"": ""dns"",\n ""value"": ""cdn-js-body. site.tld ""\n },\n {\n ""type"": ""dns"",\n ""value"": ""cdn-js-footer. site.tld ""\n },\n {\n ""type"": ""dns"",\n ""value"": ""cdn-js-head. site.tld ""\n },\n {\n ""type"": ""dns"",\n ""value"": ""www. site.tld ""\n }\n ]\n}' 2019-10-14 11:07:15,173:DEBUG:acme.client:Sending POST request to https://acme-staging-v02.api.letsencrypt.org/acme/new-order: { ""protected"": ""SOmeBASE64Str"", ""payload"": ""ANOTHERB64STR"", ""signature"": ""YETANOTHERB64STR"" } 2019-10-14 11:07:15,387:DEBUG:requests.packages.urllib3.connectionpool:https://acme-staging-v02.api.letsencrypt.org:443 ""POST /acme/new-order HTTP/1.1"" 201 1104"; RegexOptions options = RegexOptions.Multiline; foreach (Match m in Regex.Matches(input, pattern, options)) { Console.WriteLine("'{0}' found at index {1}.", m.Value, m.Index); } } }

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 C#, please visit: https://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex(v=vs.110).aspx