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 java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String[] args) { final String regex = "^(?<vendor_date>\\d{4}(?:\\-\\d\\d){2} [^,]+,[^:]+):(?<vendor_level>[^:]+):(?<vendor_component>[^:]+):(?<vendor_message>[^\\n\\r]+)(?<vendor_details>(?(?=^\\d{4}(?:\\-\\d\\d){2})|[^\\r])+)?"; final String string = "2019-10-14 11:07:08,727:DEBUG:certbot.cli:Var dry_run=True (set by user).\n" + "2019-10-14 11:07:08,727:DEBUG:certbot.cli:Var server={'dry_run', 'staging'} (set by user).\n" + "2019-10-14 11:07:08,727:DEBUG:certbot.cli:Var dry_run=True (set by user).\n" + "2019-10-14 11:07:08,728:DEBUG:certbot.cli:Var server={'dry_run', 'staging'} (set by user).\n" + "2019-10-14 11:07:08,728:DEBUG:certbot.cli:Var account={'server'} (set by user).\n" + "2019-10-14 11:07:08,757:INFO:certbot.renewal:Cert not due for renewal, but simulating renewal for dry run\n" + "2019-10-14 11:07:08,757:DEBUG:certbot.plugins.selection:Requested authenticator nginx and installer nginx\n" + "2019-10-14 11:07:10,881:DEBUG:certbot.plugins.selection:Single candidate plugin: * nginx\n" + "Description: Nginx Web Server plugin\n" + "Interfaces: IAuthenticator, IInstaller, IPlugin\n" + "Entry point: nginx = certbot_nginx.configurator:NginxConfigurator\n" + "Initialized: \n" + "Prep: True\n" + "2019-10-14 11:07:10,888:DEBUG:certbot.plugins.selection:Single candidate plugin: * nginx\n" + "Description: Nginx Web Server plugin\n" + "Interfaces: IAuthenticator, IInstaller, IPlugin\n" + "Entry point: nginx = certbot_nginx.configurator:NginxConfigurator\n" + "Initialized: \n" + "Prep: True\n" + "2019-10-14 11:07:10,889:DEBUG:certbot.plugins.selection:Selected authenticator and installer \n" + "2019-10-14 11:07:10,889:INFO:certbot.plugins.selection:Plugins selected: Authenticator nginx, Installer nginx\n" + "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'))>\n" + "2019-10-14 11:07:10,911:DEBUG:acme.client:Sending GET request to https://acme-staging-v02.api.letsencrypt.org/directory.\n" + "2019-10-14 11:07:10,998:DEBUG:requests.packages.urllib3.connectionpool:Starting new HTTPS connection (1): acme-staging-v02.api.letsencrypt.org\n" + "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\n" + "2019-10-14 11:07:14,619:DEBUG:acme.client:Received response:\n" + "HTTP 200\n" + "Server: nginx\n" + "Date: Mon, 14 Oct 2019 09:07:14 GMT\n" + "Content-Type: application/json\n" + "Content-Length: 724\n" + "Connection: keep-alive\n" + "Cache-Control: public, max-age=0, no-cache\n" + "X-Frame-Options: DENY\n" + "Strict-Transport-Security: max-age=604800\n" + "{\n" + " \"kRr68eKT_x4\": \"https://community.letsencrypt.org/t/adding-random-entries-to-the-directory/33417\",\n" + " \"keyChange\": \"https://acme-staging-v02.api.letsencrypt.org/acme/key-change\",\n" + " \"meta\": {\n" + " \"caaIdentities\": [\n" + " \"letsencrypt.org\"\n" + " ],\n" + " \"termsOfService\": \"https://letsencrypt.org/documents/LE-SA-v1.2-November-15-2017.pdf\",\n" + " \"website\": \"https://letsencrypt.org/docs/staging-environment/\"\n" + " },\n" + " \"newAccount\": \"https://acme-staging-v02.api.letsencrypt.org/acme/new-acct\",\n" + " \"newNonce\": \"https://acme-staging-v02.api.letsencrypt.org/acme/new-nonce\",\n" + " \"newOrder\": \"https://acme-staging-v02.api.letsencrypt.org/acme/new-order\",\n" + " \"revokeCert\": \"https://acme-staging-v02.api.letsencrypt.org/acme/revoke-cert\"\n" + "}\n" + "2019-10-14 11:07:14,620:INFO:certbot.main:Renewing an existing certificate\n" + "2019-10-14 11:07:14,999:DEBUG:acme.client:Requesting fresh nonce\n" + "2019-10-14 11:07:15,006:DEBUG:acme.client:Sending HEAD request to https://acme-staging-v02.api.letsencrypt.org/acme/new-nonce.\n" + "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\n" + "2019-10-14 11:07:15,158:DEBUG:acme.client:Received response:\n" + "HTTP 200\n" + "Server: nginx\n" + "Date: Mon, 14 Oct 2019 09:07:15 GMT\n" + "Connection: keep-alive\n" + "Cache-Control: public, max-age=0, no-cache\n" + "Link: https://acme-staging-v02.api.letsencrypt.org/directory;rel=\"index\"\n" + "Replay-Nonce: 0002fqXrdxZwV_xxxxx-xxxxxxxx-KdWhvOCtgFh5YNNVM\n" + "X-Frame-Options: DENY\n" + "Strict-Transport-Security: max-age=604800\n" + "2019-10-14 11:07:15,158:DEBUG:acme.client:Storing nonce: 0002fqXrdxZwV_xxxxx-xxxxxxxx-KdWhvOCtgFh5YNNVM \n" + "2019-10-14 11:07:15,160:DEBUG:acme.client:JWS payload:\n" + "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}'\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:\n" + "{\n" + " \"protected\": \"SOmeBASE64Str\",\n" + " \"payload\": \"ANOTHERB64STR\",\n" + " \"signature\": \"YETANOTHERB64STR\"\n" + "}\n" + "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"; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE); final Matcher matcher = pattern.matcher(string); while (matcher.find()) { System.out.println("Full match: " + matcher.group(0)); for (int i = 1; i <= matcher.groupCount(); i++) { System.out.println("Group " + i + ": " + matcher.group(i)); } } } }

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 Java, please visit: https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html