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
  • Match everything enclosed
    (?:...)
  • Capture everything enclosed
    (...)
  • 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

/
/
gmi

Test String

Substitution

Processing...

Code Generator

Language

Generated Code

package main import ( "regexp" "fmt" ) func main() { var re = regexp.MustCompile(`(?mi)<a\b[^>]*href\s*=\s*"cid[^"]*"[^>]*>.*<\/a>`) var str = `<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <meta name="Generator" content="Microsoft Exchange Server"> <!-- converted from rtf --> <style><!-- .EmailQuote { margin-left: 1pt; padding-left: 4pt; border-left: #800000 2px solid; } --></style> </head> <body> <font face="Arial" size="2"><span style="font-size:10pt;"> <div>notes</div> <div><font face="Calibri" size="2"><span style="font-size:11pt;"><img src="cid:0DF540471453B832E300400FF03B0900CFEC1201@1"> <a href="cid:74D8EEA6180AD131B48DC59373FABBABD7E361BB@1">GoodGEMSinstall.docx</a> </span></font></div> <div><font face="Calibri" size="2"><span style="font-size:11pt;">&nbsp;</span></font></div> <div><font face="Calibri" size="2"><span style="font-size:11pt;"><b>some</b> <span style="background-color:yellow;">formatted</span> <font size="6" color="red"><span style="font-size:22pt;">text</span></font></span></font></div> <div><font face="Calibri" size="2" color="red"><span style="font-size:11pt;">&nbsp;</span></font></div> <div><font face="Calibri" size="2"><span style="font-size:11pt;"><a href="cid:A559E9B55081418F53A3B0914D29351714C64825@1">PowerShell_transcript.20140506143510.txt</a> </span></font></div> <div><font face="Calibri" size="2"><span style="font-size:11pt;">&nbsp;</span></font></div> <div><font face="Calibri" size="2"><span style="font-size:11pt;"><a href="http://www.google.com"><font color="blue"><u>www.google.com</u></font></a></span></font></div> <div><font face="Calibri" size="2"><span style="font-size:11pt;">&nbsp;</span></font></div> <div><font face="Calibri" size="2"><span style="font-size:11pt;">some links <a href="http://www.test.fr"><font color="blue"><u>www.test.fr</u></font></a> </span></font></div> <div><font face="Calibri" size="2"><span style="font-size:11pt;">&nbsp;</span></font></div> </span></font> </body> </html> ` var substitution = "" fmt.Println(re.ReplaceAllString(str, substitution)) }

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 Golang, please visit: https://golang.org/pkg/regexp/