Regular Expressions 101

Save & Share

Flavor

  • PCRE2 (PHP >=7.3)
  • PCRE (PHP <7.3)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java 8
  • .NET 7.0 (C#)
  • Rust
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests

Tools

Sponsors
There are currently no sponsors. Become a sponsor today!
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

`
`
gmi

Test String

Substitution

Processing...

Code Generator

Language

Generated Code

# If you'd like to omit non-matching lines from the result; add ';d' to the end of the expression. sed -E 's/((?<field>[a-z0-9]*)=>)(?<value>"[a-z0-9-_'\/=> ]*")/'${field}' => ${value},/gmi;t' <<< "FldSelectAllowAdd=>\"0\" FldSelectFilter=>\"\" FldSelectFilterFld=>\"\" FldSelectForceSelection=>\"0\" FldSelectMultiple=>\"0\" FldSelectSize=>\"\" FldSelectType=>\"Values\" FldTagLnkDisp2=>\"\" FldTagLnkDisplay=>\"\" FldTagLnkDistinct=>\"0\" FldTagLnkFld=>\"\" FldTagLnkOrderBy=>\"\" FldTagLnkOrderType=>\"\" FldTagLnkTbl=>\"\" FldTagAPrefix=>\"None\" FldTagASuffix=>\"\" FldTagATarget=>\"\" FldTagAType=>\"\" FldTagCols=>\"\" FldTagHiddenValue=>\"\" FldTagImgHeight=>\"\" FldTagImgWidth=>\"\" FldTagMaxLength=>\"\" FldTagRows=>\"\" FldTagSize=>\"\" FldTagValues=>\"\" FldAdd=>\"0\" FldAddOpt=>\"1\" FldAggregate=>\"\" FldAjax=>\"0\" FldAlias=>\"0\" FldAlign=>\"\" FldAlt=>\"\" FldAttribute=>\"100\" FldAutoFill=>\"0\" FldAutoIncrement=>\"0\" FldAutoUpdateValue=>\"\" FldBasicSearch=>\"0\" FldBold=>\"0\" FldCaption=>\"Updated At\" FldCheckDuplicate=>\"0\" FldColumnWidth=>\"\" FldColumnWrap=>\"0\" FldDefault=>\"\" FldDtFormat=>\"7\" FldEdit=>\"0\" FldEditCustomAttributes=>\"\" FldEditTableField=>\"\" FldErrMsg=>\"\" FldExport=>\"0\" FldExtendedBasicSearch=>\"0\" FldFmtType=>\"Date/Time\" FldGenerate=>\"1\" FldGpDigits=>\"-2\" FldGroupBy=>\"0\" FldGroupByShowSummary=>\"0\" FldHrefFld=>\"\" FldHrefFldOrig=>\"0\" FldHtmlTag=>\"TEXT\" FldHtmlTagReadOnly=>\"0\" FldIncLeadDigit=>\"-2\" FldIsPrimaryKey=>\"0\" FldItalic=>\"0\" FldList=>\"0\" FldMax=>\"\" FldMemoCRLFReplace=>\"0\" FldMemoMaxLength=>\"0\" FldMin=>\"\" FldMultiUpdate=>\"0\" FldNumDigits=>\"0\" FldOrder=>\"\" FldOrderBy=>\"0\" FldPageIndex=>\"1\" FldParentSelect=>\"\" FldPopCalendar=>\"0\" FldQuoteE=>\"'\" FldQuoteS=>\"'\" FldRegister=>\"0\" FldRepeatColumns=>\"0\" FldReq=>\"0\" FldRequired=>\"0\" FldResizeHeight=>\"0\" FldResizeQuality=>\"75\" FldResizeWidth=>\"0\" FldRptAggAvg=>\"0\" FldRptAggMax=>\"0\" FldRptAggMin=>\"0\" FldRptAggSum=>\"0\" FldSearch=>\"0\" FldSize=>\"26\" FldSourceField=>\"\" FldSourceName=>\"\" FldSourceTable=>\"\" FldSrchOpr=>\"=>\" FldSrchOpr2=>\"\" FldStrFunc=>\"\" FldSupport=>\"1\" FldTitle=>\"\" FldType=>\"135\" FldTypeName=>\"TIMESTAMP\" FldUniqueIdx=>\"0\" FldUploadPath=>\"\" FldUploadResize=>\"0\" FldUseDHTMLEditor=>\"0\" FldUseParen=>\"-2\" FldValidate=>\"EURODATE\" FldView=>\"0\" FldViewCustomAttributes=>\"\" FldViewTag=>\"FORMATTED TEXT\" FldViewThumbnail=>\"0\" FldZeroLen=>\"1\" FileNameFld=>\"\" FileSizeFld=>\"\" FileTypeFld=>\"\" ImageHeightFld=>\"\" ImageWidthFld=>\"\" NativeDataType=>\"7\""

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 SED, please visit: https://www.gnu.org/software/sed/manual/html_node/The-_0022s_0022-Command.html