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

const regex = /(?:URLSICategory|DNSSICategory|IPReputationSICategory)/gm; // Alternative syntax using RegExp constructor // const regex = new RegExp('(?:URLSICategory|DNSSICategory|IPReputationSICategory)', 'gm') const str = `Rcvd:2021-04-15T11:17:46.673993+10:00 From:firewall-1.site.com Time:2021-04-15T01:17:45 Host:firewall-1 Pri:alert.info Msg: %FTD-6-430002: EventPriority: High, DeviceUUID: 00000000-0000-0000-0000-000000000001, InstanceID: 16, FirstPacketSecond: 2021-04-15T01:17:45Z, ConnectionID: 35916, AccessControlRuleAction: Block, AccessControlRuleReason: IP Block, SrcIP: 10.0.0.8, DstIP: 1.2.3.9, SrcPort: 16403, DstPort: 16386, Protocol: udp, IngressInterface: Inside, EgressInterface: Outside, IngressZone: INSIDE, EgressZone: OUTSIDE, IngressVRF: Global, EgressVRF: Global, ACPolicy: ACP-XX-20210329, Prefilter Policy: PFP-XX-20210329, InitiatorPackets: 1, ResponderPackets: 0, InitiatorBytes: 58, ResponderBytes: 0, NAPPolicy: No Rules Active, SecIntMatchingIP: Destination, IPReputationSICategory: Global-Blacklist_1 Rcvd:2021-04-15T11:17:49.924536+10:00 From:firewall-1.site.com Time:2021-04-15T01:17:49 Host:firewall-1 Pri:alert.info Msg: %FTD-6-430003: EventPriority: Low, DeviceUUID: 00000000-0000-0000-0000-000000000001, FirstPacketSecond: 2021-04-15T01:17:49Z, ConnectionID: 0, AccessControlRuleAction: Allow, SrcIP: 10.0.0.1, DstIP: 1.2.3.4, SrcPort: 54102, DstPort: 443, Protocol: tcp, IngressInterface: Inside, EgressInterface: Outside, IngressZone: INSIDE, EgressZone: OUTSIDE, IngressVRF: Global, EgressVRF: Global, ACPolicy: ACP-XX-20210329, AccessControlRuleName: From-IPv4-allowed-users, Prefilter Policy: PFP-XX-20210329, User: Not Found, ConnectionDuration: 0, InitiatorPackets: 12, ResponderPackets: 15, InitiatorBytes: 1419, ResponderBytes: 12575, NAPPolicy: No Rules Active Rcvd:2021-04-15T12:53:40.111154+10:00 From:firewall-1.site.com Time:2021-04-15T02:53:39 Host:firewall-1 Pri:alert.info Msg: %FTD-6-430003: EventPriority: Low, DeviceUUID: 00000000-0000-0000-0000-000000000001, FirstPacketSecond: 2021-04-15T02:53:39Z, ConnectionID: 0, AccessControlRuleAction: Allow, SrcIP: 10.0.0.2, DstIP: 1.2.3.5, SrcPort: 48012, DstPort: 443, Protocol: tcp, IngressInterface: Inside, EgressInterface: Outside, IngressZone: INSIDE, EgressZone: OUTSIDE, IngressVRF: Global, EgressVRF: Global, ACPolicy: ACP-XX-20210329, AccessControlRuleName: From-IPv4-allowed-users, Prefilter Policy: PFP-XX-20210329, User: Not Found, ConnectionDuration: 0, InitiatorPackets: 10, ResponderPackets: 15, InitiatorBytes: 1678, ResponderBytes: 12575, NAPPolicy: No Rules Active Rcvd:2021-04-15T12:53:40.112896+10:00 From:firewall-1.site.com Time:2021-04-15T02:53:40 Host:firewall-1 Pri:alert.info Msg: %FTD-6-430003: EventPriority: Low, DeviceUUID: 00000000-0000-0000-0000-000000000001, FirstPacketSecond: 2021-04-15T02:53:40Z, ConnectionID: 0, AccessControlRuleAction: Allow, SrcIP: 10.0.0.3, DstIP: 1.2.3.6, SrcPort: 48019, DstPort: 443, Protocol: tcp, IngressInterface: Inside, EgressInterface: Outside, IngressZone: INSIDE, EgressZone: OUTSIDE, IngressVRF: Global, EgressVRF: Global, ACPolicy: ACP-XX-20210329, AccessControlRuleName: From-IPv4-allowed-users, Prefilter Policy: PFP-XX-20210329, User: Not Found, ConnectionDuration: 0, InitiatorPackets: 11, ResponderPackets: 15, InitiatorBytes: 1678, ResponderBytes: 12575, NAPPolicy: No Rules Active Rcvd:2021-04-15T12:53:40.123993+10:00 From:firewall-1.site.com Time:2021-04-15T01:17:45 Host:firewall-1 Pri:alert.info Msg: %FTD-6-430002: EventPriority: High, DeviceUUID: 00000000-0000-0000-0000-000000000002, InstanceID: 16, FirstPacketSecond: 2021-04-15T01:17:45Z, ConnectionID: 35916, AccessControlRuleAction: Block, AccessControlRuleReason: IP Block, SrcIP: 10.0.0.4, DstIP: 1.2.3.7, SrcPort: 16403, DstPort: 16386, Protocol: udp, IngressInterface: Inside, EgressInterface: Outside, IngressZone: INSIDE, EgressZone: OUTSIDE, IngressVRF: Global, EgressVRF: Global, ACPolicy: ACP-XX-20210329, Prefilter Policy: PFP-XX-20210329, InitiatorPackets: 1, ResponderPackets: 0, InitiatorBytes: 58, ResponderBytes: 0, NAPPolicy: No Rules Active, SecIntMatchingIP: Destination, IPReputationSICategory: Global-Blacklist_1 Rcvd:2021-04-15T12:53:40.130404+10:00 From:firewall-2.site.com Time:2021-04-15T12:53:40 Host:firewall-2 Pri:local4.err Msg::Apr 15 02:53:40 UTC: %FTD-session-3-106014: Deny inbound icmp src Inside:10.1.0.1 dst nlp_int_tap:169.254.1.2 (type 3, code 3) `; // Reset `lastIndex` if this regex is defined globally // regex.lastIndex = 0; let m; while ((m = regex.exec(str)) !== null) { // This is necessary to avoid infinite loops with zero-width matches if (m.index === regex.lastIndex) { regex.lastIndex++; } // The result can be accessed through the `m`-variable. m.forEach((match, groupIndex) => { console.log(`Found match, group ${groupIndex}: ${match}`); }); }

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 JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions