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

`
`
g

Test String

Code Generator

Language

Generated Code

package main import ( "regexp" "fmt" ) func main() { var re = regexp.MustCompile(`\[((?P<serial>\d{14}){0,1}[\.\w]*-(?P<pccode>[\dA-Z]{8}))\] +`) var str = `2017-06-15 06:05:25*6 --- ERROR "?? ?.?.?. ??? ????? ????????"--- FieldName:AFM, OldValue:, NewValue:125433937 2017-06-15 06:05:25*6 [01102409405015-02CB3A00] setData ---- ESoftOneError: ?? ?.?.?. ??? ????? ???????? ***** 2017-06-15 06:05:25*6 [01102409405015-02CB3A00] getData ---- EDatabaseError: [42S22] [Microsoft][ODBC Driver 11 for SQL Server][SQL Server]Invalid column name 'false'. (207) [42S22] [Microsoft][ODBC Driver 11 for SQL Server][SQL Server]Invalid column name 'false'. (207) [42S22] [Microsoft][ODBC Driver 11 for SQL Server][SQL Server]Invalid column name 'false'. (207) 2017-06-15 06:05:46*3 [01100279451010-0D6626F0] calculate ---- Time: 4922 ms QCount: 29 QTime: 4624 DataIn: 1990 DataOut: 2576 [37 Trs - 224 MB - 18 %] 2017-06-15 06:05:51*3 [01100279451010-0D6626F0] setData ---- Time: 3437 ms QCount: 62 QTime: 265 DataIn: 1054 DataOut: 30 2017-06-15 06:06:14*5 [01102396363715-0839E1A0] Report (customer) ---- Time: 719 ms QCount: 1 QTime: 703 [176 Trs - 161 MB - 11 %] 2017-06-15 09:35:00*1 [01102342340813-86ED1F51] ******EXCEPTION ProcessPacket disp_ExecuteSQL EDatabaseError: [42000] [Microsoft][SQL Server Native Client 11.0][SQL Server]Incorrect syntax near 'SAMSUNG'. (102) [42000] [Microsoft][SQL Server Native Client 11.0][SQL Server]The identifier that starts with '</productDesc> <svcLevel>EDX0W</svcLevel> <svcLevelDesc>Express ; Customer requested day service</svcLevelDesc> <' is too long. Maximum length is 128. (103) 2017-06-14 08:42:49*2 [01102455824916-C29C87D0] ******EXCEPTION ProcessPacket disp_GetSQLResults EDatabaseError: [42S22] [Microsoft][ODBC Driver 11 for SQL Server][SQL Server]Invalid column name 'FIDNOC'. (207) [UPDATE ML SET ML.FINALDATE = CONVERT(VARCHAR,DATEADD(DD,M.CCCLOTDURATION,FD.TRNDATE),103) FROM FINDOC AS FD INNER JOIN MTRLINES AS FDL ON FDL.FINDOC = FD.FINDOC INNER JOIN MTRL AS M ON M.MTRL = FDL.MTRL AND M.CCCLOTDURATION IS NOT NULL INNER JOIN MTRLOT AS ML ON ML.MTRL = M.MTRL AND ML.MT] [13100 Trs - 464 MB - 5 %]` 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/