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

/
/
gU

Test String

Substitution

Processing...

Code Generator

Language

Generated Code

re = /<a(.*)href="([^"]*)"(.*)>/ str = '<p><b>Piano:</b><br /></p><p><a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3374"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2302.jpg" alt="Griglie in ghisa" title="Griglie in ghisa" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3368"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2300.jpg" alt="Bruciatore Ultrarapido" title="Bruciatore Ultrarapido" /></a> <br /></p><p class="dot">7 bruciatori a gas, di cui 1 Ultrarapido (4,2 kW)<br /></p><p><br /></p><p><b>Forno principale, superiore:</b><br /></p><p><a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3372"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/A.jpg" alt="A" title="A" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/4225"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func1548.jpg" alt="4 livelli di cottura" title="4 livelli di cottura" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3369"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2320.jpg" alt="Smalto Ever Clean" title="Smalto Ever Clean" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3665"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func1518.jpg" alt="Volta Mobile" title="Volta Mobile" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3371"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2318.jpg" alt="Interno porta tuttovetro" title="Interno porta tuttovetro" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3671"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2316.jpg" alt="Vetro interno rimovibile" title="Vetro interno rimovibile" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3373"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2314.jpg" alt="Porta a triplo vetro" title="Porta a triplo vetro" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3370"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2324.jpg" alt="Raffreddamento tangenziale" title="Raffreddamento tangenziale" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3675"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2328.jpg" alt="Guide telescopiche" title="Guide telescopiche" /></a> <br /></p><p class="dot">Forno elettrico multifunzione termoventilato, 7 funzioni<br /></p><p>compresa funzione di pulizia Vapor Clean<br /></p><p class="dot">Opzione programmazione di inizio e fine cottura con allarme<br /></p><p>acustico di fine cottura<br /></p><p class="dot">Display / Orologio: elettronico a 5 tasti<br /></p><p><b>Forno secondario, inferiore:</b><br /></p><p><a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3372"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/A.jpg" alt="A" title="A" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/4225"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func1548.jpg" alt="4 livelli di cottura" title="4 livelli di cottura" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3369"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2320.jpg" alt="Smalto Ever Clean" title="Smalto Ever Clean" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3665"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func1518.jpg" alt="Volta Mobile" title="Volta Mobile" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3371"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2318.jpg" alt="Interno porta tuttovetro" title="Interno porta tuttovetro" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3671"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2316.jpg" alt="Vetro interno rimovibile" title="Vetro interno rimovibile" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3373"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2314.jpg" alt="Porta a triplo vetro" title="Porta a triplo vetro" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3370"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2324.jpg" alt="Raffreddamento tangenziale" title="Raffreddamento tangenziale" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3675"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2328.jpg" alt="Guide telescopiche" title="Guide telescopiche" /></a> <br /></p><p class="dot">Forno elettrico multifunzione ventilato, 7 funzioni<br /></p><p>compresa funzione di pulizia Vapor Clean<br /></p><p><b>Forno ausiliario, superiore:</b><br /></p><p><a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/4710"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func1552.jpg" alt="2 livelli di cottura" title="2 livelli di cottura" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3369"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2320.jpg" alt="Smalto Ever Clean" title="Smalto Ever Clean" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3665"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func1518.jpg" alt="Volta Mobile" title="Volta Mobile" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3371"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2318.jpg" alt="Interno porta tuttovetro" title="Interno porta tuttovetro" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3671"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2316.jpg" alt="Vetro interno rimovibile" title="Vetro interno rimovibile" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3373"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2314.jpg" alt="Porta a triplo vetro" title="Porta a triplo vetro" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3370"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2324.jpg" alt="Raffreddamento tangenziale" title="Raffreddamento tangenziale" /></a> <br /></p><p class="dot">Forno elettrico 1 funzione<br /></p><p><br /></p><p class="dot">Vano portaoggetti con apertura a cassetto<br /></p><p class="dot"><b>Porta dei forni principale e secondario con apertura <br /></p><p>laterale</b><br /></p><p class="dot">DIMENSIONI: LxPxH 110x60x91 cm</p>' subst = '<a$1href="javascript:alert(\\\'Test\\\');"$3>' result = str.gsub(re, subst) # Print the result of the substitution puts 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 Ruby, please visit: http://ruby-doc.org/core-2.2.0/Regexp.html