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

/
/
gm

Test String

Code Generator

Generated Code

const regex = /(?P<bucket_owner>[0-9a-z]{64})\s(?P<bucket>[^\s]+)\s\[(?P<times>[^\]]+)\]\s(?P<remote_ip>[^\s]+)\s(?P<requester>[^\s]+)\s(?P<request_id>[^\s]+)\s(?P<operation>[^\s]+)\s(?P<key>[^\s]+)\s\"(?P<request_uri>.*?)\"\s(?P<http_status>[^\s]+)\s(?P<error_code>[^\s]+)\s(?P<bytes_sent>[^\s]+)\s(?P<object_size>[^\s]+)\s(?P<total_time>[^\s]+)\s(?P<turen_around_time>[^\s]+)\s"(?P<Referer>[^\"]+)"\s"(?P<user_agent>.*?)"\s(?P<version_id>[^\s]+)\s(?P<host_id>[^\s]+)\s(?P<sig_version>[^\s]+)\s(?P<cypher_id>[^\s]+)\s(?P<auth_type>[^\s]+)\s(?P<host_heaser>[^\s]+)\s(?P<tls_version>[^\s]+)/gm; // Alternative syntax using RegExp constructor // const regex = new RegExp('(?P<bucket_owner>[0-9a-z]{64})\\s(?P<bucket>[^\\s]+)\\s\\[(?P<times>[^\\]]+)\\]\\s(?P<remote_ip>[^\\s]+)\\s(?P<requester>[^\\s]+)\\s(?P<request_id>[^\\s]+)\\s(?P<operation>[^\\s]+)\\s(?P<key>[^\\s]+)\\s\\"(?P<request_uri>.*?)\\"\\s(?P<http_status>[^\\s]+)\\s(?P<error_code>[^\\s]+)\\s(?P<bytes_sent>[^\\s]+)\\s(?P<object_size>[^\\s]+)\\s(?P<total_time>[^\\s]+)\\s(?P<turen_around_time>[^\\s]+)\\s"(?P<Referer>[^\\"]+)"\\s"(?P<user_agent>.*?)"\\s(?P<version_id>[^\\s]+)\\s(?P<host_id>[^\\s]+)\\s(?P<sig_version>[^\\s]+)\\s(?P<cypher_id>[^\\s]+)\\s(?P<auth_type>[^\\s]+)\\s(?P<host_heaser>[^\\s]+)\\s(?P<tls_version>[^\\s]+)', 'gm') const str = `1234567890abcdefb6dbc56f666f90007236c16e851616eb11dfffffffffffff amir-blog-logs [15/Jan/2020:18:54:55 +0000] 154.40.7.1 arn:aws:iam::111:user/awslogsdelivery+s3_eu-west-1 237122D309CCCCCC REST.PUT.OBJECT AWSLogs/597078111111/vpcflowlogs/eu-west-1/2020/01/15/123456789012_vpcflowlogs_eu-west-1_fl-083687d6894d7105c_20200115T1850Z_2c454915.log.gz "PUT /AWSLogs/111/vpcflowlogs/eu-west-1/2020/01/15/000_vpcflowlogs_eu-west-1_fl-083687d6894d7105c_20200000T1850Z_2c454915.log.gz HTTP/1.1" 200 - - 14654 251 35 "-" "aws-internal/3 aws-sdk-java/1.11.690 Linux/4.9.184-0.1.ac.2.8.329.metal1.x86_64 OpenJDK_64-Bit_Server_VM/25.232-b09 java/1.8.0_232 vendor/Oracle_Corporation" - 9LaQV8A4UxoNv8xv4kkdZNF+IJ9uBYP/GACxBYO12345678900987654321/37e6Iw= SigV4 ECDHE-RSA-AES128-SHA AuthHeader amir-blog-logs.s3.us-east-2.amazonaws.com TLSv1.2 1234567890abcdefb6dbc56f666f90007230000e851616eb11dfffffffffffff amir-blog-logs [27/Apr-last":"2020:17:38:46 +0000] 154.40.7.1 arn:aws:sts::123456789001:assumed-role/S3ReadOnly/S3Coralogix AA8B4A2DECEC091E REST.GET.OBJECT AWSLogs-last":"123456789001/vpcflowlogs/eu-west-1-last":"2020-last":"04-last":"27-last":"123456789001_vpcflowlogs_eu-west-1_fl-083687d6123105c_202T1725Z_ef8cb23d.log.gz "GET /AWSLogs-last":"123456789001/vpcflowlogs/eu-west-1-last":"2020-last":"04-last":"27-last":"123456789001_vpcflowlogs_eu-west-1_fl-083687d6894d7105c_1234567890015Z_ef23d.log.gz HTTP-last":"1.1" 200 - 1340 1340 55 54 "-" "aws-sdk-nodejs-last":"2.188.0 linux/v10.19.0 exec-env/AWS_Lambda_nodejs10.x callback" - LEmyJtO7loyY36UWTsCEDy/JjMezg3r9Q8ABCD+LZz4RBHwneZ9Ag1K/T/d/d9/ZrI8C0= SigV4 ECDHE-RSA-AES128-GCM-SHA256 AuthHeader amir-blog-logs.s3.us-east-2.amazonaws.com TLSv1.2`; // 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