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

/
/

Test String

Code Generator

Language

Generated Code

package main import ( "regexp" "fmt" ) func main() { var re = regexp.MustCompile(`(?!.*\/)(.*)-(([^-]+)-([0-9]+))-([^.]+)(\.chi\.zst)`) var str = `http://localhost/ http://localhost/packages/a/ http://localhost/packages/b/ http://localhost/packages/c/ http://localhost/packages/core/ http://localhost/packages/d/ http://localhost/packages/e/ http://localhost/packages/f/ http://localhost/packages/g/ http://localhost/packages/h/ http://localhost/packages/i/ http://localhost/packages/j/ http://localhost/packages/k/ http://localhost/packages/l/ http://localhost/packages/m/ http://localhost/packages/meta/ http://localhost/packages/n/ http://localhost/packages/o/ http://localhost/packages/p/ http://localhost/packages/q/ http://localhost/packages/r/ http://localhost/packages/s/ http://localhost/packages/t/ http://localhost/packages/u/ http://localhost/packages/v/ http://localhost/packages/w/ http://localhost/packages/x/ http://localhost/packages/y/ http://localhost/packages/z/ http://localhost/packages/a/atkmm-2.28.2-2-x86_64.chi.zst http://localhost/packages/a/atom-1.61.0beta0-2-x86_64.chi.zst http://localhost/packages/a/atril-1.26.0-1-x86_64.chi.zst http://localhost/packages/a/attica-5.94.0-1-x86_64.chi.zst http://localhost/packages/a/attr-2.5.1-2-x86_64.chi.zst http://localhost/packages/a/aubio-0.4.9-13-x86_64.chi.zst http://localhost/packages/a/aubio-0.4.9-7-x86_64.chi.zst http://localhost/packages/a/audacious-4.0.5-1-x86_64.chi.zst http://localhost/packages/a/audacious-plugins-4.0.5-1-x86_64.chi.zst http://localhost/packages/a/audacity-1:2.4.1-7-x86_64.chi.zst http://localhost/packages/a/audiofile-0.3.6-6-x86_64.chi.zst http://localhost/packages/a/audit-3.0.8-1-x86_64.chi.zst http://localhost/packages/a/augeas-1.12.0-2-x86_64.chi.zst http://localhost/packages/a/auracle-git-r366.8739929-4-x86_64.chi.zst ` if len(re.FindStringIndex(str)) > 0 { fmt.Println(re.FindString(str),"found at index",re.FindStringIndex(str)[0]) } }

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/