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

/
/
gm

Test String

Code Generator

Language

Generated Code

package main import ( "regexp" "fmt" ) func main() { var re = regexp.MustCompile(`(?m)\b((bc|tb)(0([ac-hj-np-z02-9]{39}|[ac-hj-np-z02-9]{59})|1[ac-hj-np-z02-9]{8,87})|([13]|[mn2])[a-km-zA-HJ-NP-Z1-9]{25,39})\b\s`) var str = `BTC Address: 1JHwenDp9A98XdjfYkHKyiE3R99Q72K9X4 BTC Address: 1Unoc4af6gCq3xzdDFmGLpq18jbTW1nZD BTC Address: 1A8Ad7VbWDqwmRY6nSHtFcTqfW2XioXNmj BTC Address: 12CZYvgNZ2ze3fGPFzgbSCELBJ6zzp2cWc BTC Address: 17drmHLZMsCRWz48RchWfrz9Chx1osLe67 Receiving Bitcoin Address: 15LZALXitpbkK6m2QcbeQp6McqMvgeTnY8 Receiving Bitcoin Address: 1MAFzYQhm6msF2Dxo3Nbox7i61XvgQ7og5 -------------------------------------------------------- Other possible BitCoin test cases I added: -------------------------------------------------------- - What if text comes before and/or after on same line? Or doesn't contain BitCoin/BTC/etc. anywhere (or anywhere close to the address)? Send BitCoin payments here 1MAFzYQhm6msF2Dxo3Nbox7i61XvgQ7og5 1MAFzYQhm6msF2Dxo3Nbox7i61XvgQ7og5 to keep your secrets safe. Send payments here 1MAFzYQhm6msF2Dxo3Nbox7i61XvgQ7og5 to keep your secrets safe. - Standalone address: 1Dvd7Wb72JBTbAcfTrxSJCZZuf4tsT8V72 -------------------------------------------------------- Redacted Body content generating FPs from spam emails: -------------------------------------------------------- src=3D"https://example.com/blah=3D2159024400&amp;t=3DXWP9YVkAYwkmif9RgKeoPhw2b1zdMnMzXZSGRD_Oxkk" "cursor:pointer;color:#6A6C6D;-webkit-text-size-blahutm_campaign%253Drdboards%2526e_t%253Dd5c2deeaae5c4a8b8d2bff4d0f87ecdd%2526utm_cont=blah src=3D"https://example.com/blah/74/328e74997261d5228886aab1a2da6874.jpg" src=3D"https://example.com/blah-1c779f59948fc5be8a461a4da8d938aa.jpg" href=3D"https://example.com/blah-0ff3169b28a6e17ae8a369a3161734c1?alert_=id=blah` for i, match := range re.FindAllString(str, -1) { fmt.Println(match, "found at index", i) } }

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/