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

/
/
gm

Test String

Code Generator

Language

Generated Code

package main import ( "regexp" "fmt" ) func main() { var re = regexp.MustCompile(`(?m)^file *"?([^" ]*)"[\s\S]*?((?:{[\s\S]*?)*?}[\s\S]})`) var str = `############################################################################# # DB substitution file generated by http://github.com/epics-containers/ibek # ############################################################################# file "$(IOCSTATS)/db/iocAdminSoft.db" { pattern { "IOC" } { "BL01T-EA-TST-02" } } file "$(IOCSTATS)/db/iocAdminScanMon.db" { pattern { "IOC" } { "BL01T-EA-TST-02" } } file "$(ADSIMDETECTOR)/db/simDetector.template" { pattern { "P", "R", "PORT", "TIMEOUT", "ADDR" } { "BL01T-EA-TST-02", ":DET:", "DET.DET", "1", "0" } } file "$(ADCORE)/db/NDPva.template" { pattern { "NDARRAY_PORT", "ADDR", "SCANRATE", "NDARRAY_ADDR", "ENABLED", "P", "R", "TIMEOUT", "PORT" } { "DET.DET", "0", "I/O Intr", "0", "0", "BL01T-EA-TST-02", ":PVA:", "1", "DET.PVA" } } file "$(ADCORE)/db/NDStdArrays.template" { pattern { "NDARRAY_PORT", "FTVL", "ADDR", "SCANRATE", "NELEMENTS", "NDARRAY_ADDR", "ENABLED", "P", "R", "TIMEOUT", "TYPE", "PORT" } { "DET.DET", "CHAR", "0", "I/O Intr", "1048576", "0", "0", "BL01T-EA-TST-02", ":ARR:", "1", "Int8", "DET.ARR" } } file "simDetector.pvi.template" { pattern { "P", "R" } { "BL01T-EA-TST-02", ":DET:" } } file "NDPluginPva.pvi.template" { pattern { "P", "R" } { "BL01T-EA-TST-02", ":PVA:" } } file "NDPluginStdArrays.pvi.template" { pattern { "P", "R" } { "BL01T-EA-TST-02", ":ARR:" } } ` 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/