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

Substitution

Processing...

Code Generator

Language

Generated Code

// include the latest version of the regex crate in your Cargo.toml extern crate regex; use regex::Regex; fn main() { let regex = Regex::new(r"(?m)(?<=[a-z])(=+)(?!\w)").unwrap(); let string = "<!-- This is an automatically generated file. It will be read and overwritten. DO <META HTTP-EQUIV=\"Content-Type\" CONTENT=\"text/html; charset=UTF-8\"> <TITLE>Bookmarks</TITLE> <H1>Bookmarks</H1> <DL><p> <DT><A HREF=\"https://translate.google.com/details?sl=en&tl=ar&text=groundwork&op=translate\" ADD_DATE=\"1666511420\" ICON=\"data:image/png;base64,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\">underlag/groundwork/foundation/العمل التحضيري/الأساس/</A> <DT><H3 ADD_DATE=\"1727566144\" LAST_MODIFIED=\"1727566144\">produksjonsunderlag=production basis=()(أساس الإنتاج )</H3> </DL><p> <DT><H3 ADD_DATE=\"1727566144\" LAST_MODIFIED=\"1727566144\">antitrust==(مكافحة الاحتكار)</H3> <DL><p>"; let substitution = "|"; // result will be a String with the substituted value let result = regex.replace_all(string, substitution); println!("{}", result); }

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 Rust, please visit: https://docs.rs/regex/latest/regex/