Regular Expressions 101

Save & Share

  • Regex Version: ver. 1
  • Update Regex
    ctrl+⇧+s
  • Save new Regex
    ctrl+s
  • Add to Community Library

Flavor

  • PCRE2 (PHP >=7.3)
  • PCRE (PHP <7.3)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java 8
  • .NET 7.0 (C#)
  • Rust
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests

Tools

Sponsors
There are currently no sponsors. Become a sponsor today!
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 = @"\""event_sub_type\"":\""((WAN\s+Firewall)|TLS)"; string input = @"1. event_sub_type"":""WAN {""event_count"":1,""ISP_name"":""Shanghai internet"",""rule"":""Initial Connectivity Rule"",""dest_is_site_or_vpn"":""Site"",""src_isp_ip"":""0.0.0.0"",""time_str"":""2023-11-28T04:27:40Z"",""src_site"":""CHINA-AZURE-E2"",""src_ip"":""0.0.0.1"",""internalId"":""54464646"",""dest_site_name"":""china_112,""event_type"":""Security"",""src_country_code"":""CN"",""action"":""Monitor"",""subnet_name"":""cn-001.net-vnet-1"",""pop_name"":""Shanghai_1"",""dest_port"":443,""dest_site"":""china_connect"",""rule_name"":""Initial Connectivity Rule"",""event_sub_type"":""WAN Firewall"",""insertionDate"":1701188916690,""ip_protocol"":""TCP"",""rule_id"":""101238"",""src_is_site_or_vpn"":""Site"",""account_id"":5555,""application"":""HTTP(S)"",""src_site_name"":""china_connect"",""src_country"":""China"",""dest_ip"":""0.0.0.0"",""os_type"":""OS_ANDROID"",""app_stack""TCP"",""TLS"",""HTTP(S)""],""time"":1701188860834} 2. ""event_sub_type"":""TLS"","" {""event_count"":4,""http_host_name"":""isp.vpn"",""ISP_name"":""China_internet"",""src_isp_ip"":""0.0.0.0"",""tls_version"":""TLSv1.3"",""time_str"":""2023-11-28T04:27:16Z"",""src_site"":""china_mtt"",""src_ip"":""0.0.0.0"",""internalId"":""rtrgrtr"",""domain_name"":""china.gh.com"",""event_type"":""Security"",""src_country_code"":""CN"",""tls_error_description"":""unknown CA"",""action"":""Alert"",""subnet_name"":""0.0.0.0/24"",""pop_name"":""china_1"",""dest_port"":443,""event_sub_type"":""TLS"",""insertionDate"":1701188915580,""dest_country_code"":""SG"",""tls_error_type"":""fatal"",""dns_name"":""china.com"",""traffic_direction"":""OUTBOUND"",""src_is_site_or_vpn"":""Site"",""account_id"":56565,""application"":""Netskope"",""src_site_name"":""CHINA-44"",""src_country"":""China"",""dest_ip"":""0.0.0.0"",""os_type"":""OS_WINDOWS"",""time"":1701188836011,""dest_country"":""Singapore""}"; 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