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

/
/
g

Test String

Code Generator

Language

Generated Code

const regex = /(?P<cdn_node_ip>\S+) - (?P<client_ip>\S+) - - \[(?P<date>\S+)\] "(?P<verb>\w+) (?P<url>\/(?P<delivery_type_code>\S+?)\/(?P<delivery_type>\S+?)\/(?P<bucket_id>\S+?)\/(?P<file_path>.*)) (?P<version>\S+) (?P<referrer_url>\S+)" (?P<status_code>\d+) (?P<content_length>\d+) (?P<bytes_transferred>\d+) (?P<duration>\d+) (?P<cached>-|\d+) "(?P<user_agent>.*?)" "(?P<ep_region_id>\d+) (?P<user_region_id>\d+) (?P<ep_pid>\d+) (?P<user_pid>\d+) (?P<hash_content>\S+)" "("|(?P<download_id>\d+) (?P<origin>\S+) (?P<retries>\d+) (?P<code>\d+) (?P<time>\d+) (?P<p2p>\d+)") (?P<host>\S+) (?P<request_id>\d+) (?P<http_request>\d+) (?P<cache_tier_name>\S+) (?P<layer>\d)/g; // Alternative syntax using RegExp constructor // const regex = new RegExp('(?P<cdn_node_ip>\\S+) - (?P<client_ip>\\S+) - - \\[(?P<date>\\S+)\\] "(?P<verb>\\w+) (?P<url>\\\/(?P<delivery_type_code>\\S+?)\\\/(?P<delivery_type>\\S+?)\\\/(?P<bucket_id>\\S+?)\\\/(?P<file_path>.*)) (?P<version>\\S+) (?P<referrer_url>\\S+)" (?P<status_code>\\d+) (?P<content_length>\\d+) (?P<bytes_transferred>\\d+) (?P<duration>\\d+) (?P<cached>-|\\d+) "(?P<user_agent>.*?)" "(?P<ep_region_id>\\d+) (?P<user_region_id>\\d+) (?P<ep_pid>\\d+) (?P<user_pid>\\d+) (?P<hash_content>\\S+)" "("|(?P<download_id>\\d+) (?P<origin>\\S+) (?P<retries>\\d+) (?P<code>\\d+) (?P<time>\\d+) (?P<p2p>\\d+)") (?P<host>\\S+) (?P<request_id>\\d+) (?P<http_request>\\d+) (?P<cache_tier_name>\\S+) (?P<layer>\\d)', 'g') const str = `10.95.151.28 - 10.95.151.253 - - [22/Jan/2019:10:41:45.956] "GET /P/0/_53/video_68473.fakevideo HTTP/1.1 -" 404 42 42 4019 - "curl/7.29.0" "1 2 1 2 03" "" b53.1.qacdndev.cdn.hi.inet 3 0 hdd 0`; // 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