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

~
~
x

Test String

Code Generator

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#"(?x){@ (?<cond>\w+) - (?<stat>\w+(?:%\w+)*) (?: : (?<sub>\w+))? \| # a "THEN" part that doesn't have a nested conditional statement (?<then>[^{|@]*+ (?: {(?!@) [^{|@]* | @(?!}) [^{|@]* )*+ ) # optional "ELSE" part (the content is similar to the "THEN" part) (?: \| (?<else> \g<then> ) )? (*SKIP) @}"#).unwrap(); let string = "{@if-is_not_logged_homepage| <header id=\"header_home\"> <div class=\"in\"> <div class=\"top\"> <h1 class=\"logo\"><a href=\"/\"><img src=\"/img/logo-home.png\" alt=\"\"></a></h1> <div class=\"login_outer_wrapper\"> <button id=\"login\"><div class=\"a\"><i class=\"stripe\"><i></i></i>Log in</div></button> <div id=\"login_wrapper\"> <form method=\"post\" action=\"{^login^}\" id=\"form_login_global\"> <div class=\"form_field no_description\"> <label>{!auth:login_email!}</label> <div class=\"input\"><input type=\"text\" name=\"form[login]\"></div> </div> <div class=\"form_field no_description password\"> <label>{!auth:password!}</label> <div class=\"input\"><input type=\"password\" name=\"form[password]\"></div> </div> <div class=\"remember\"> <input type=\"checkbox\" name=\"remember\" id=\"remember_me_check\" checked> <label for=\"remember_me_check\"><i class=\"fa fa-check\" aria-hidden=\"true\"></i>Remember</label> </div> <div class=\"submit_box\"> <button class=\"btn btn_check\">Log in</button> </div> </form> </div> </div> </div> <div class=\"content clr\"> <div class=\"main_menu\"> <a href=\"\"> <i class=\"ico a\"><i class=\"fa fa-lightbulb-o\" aria-hidden=\"true\"></i></i> <span>Idea</span> <div>&nbsp;</div> </a> <a href=\"\"> <i class=\"ico b\"><i class=\"fa fa-user\" aria-hidden=\"true\"></i></i> <span>FFa</span> </a> <a href=\"\"> <i class=\"ico c\"><i class=\"fa fa-briefcase\" aria-hidden=\"true\"></i></i> <span>Buss</span> </a> </div> <div class=\"text_wrapper\"> <div> <div class=\"register_wrapper\"> <a id=\"main_register\" class=\"btn register\">Załóż konto</a> <form method=\"post\" action=\"{^login^}\" id=\"form_register_home\"> <div class=\"form_field no_description\"> <label>{!auth:email!}</label> <div class=\"input\"><input type=\"text\" name=\"form2[email]\"></div> </div> <div class=\"form_field no_description password\"> <label>{!auth:password!}</label> <div class=\"input tooltip\"><input type=\"password\" name=\"form2[password]\"><i class=\"fa fa-info-circle tooltip_open\" aria-hidden=\"true\" title=\"{!auth:password_format!}\"></i></div> </div> <div class=\"form_field terms no_description\"> <div class=\"input\"> <input type=\"checkbox\" name=\"form2[terms]\" id=\"terms_check\"> <label for=\"terms_check\"><i class=\"fa fa-check\" aria-hidden=\"true\"></i>Agree</label> </div> </div> <div class=\"form_field no_description\"> <div class=\"input captcha_wrapper\"> <div class=\"g-recaptcha\" data-sitekey=\"{%captcha_public_key%}\"></div> </div> </div> <div class=\"submit_box\"> <button class=\"btn btn_check\">{!auth:register_btn!}</button> </div> </form> </div> </div> </div> </div> </div> </header> | babubibo @}"; // result will be a tuple containing the start and end indices for the first match in the string let result = regex.captures(string); let (start, end) = match result { Some((s, e)) => (s, e), None => { // ... } }; println!("{}", &string[start, end]); }

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/