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
Processing...

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/<outcomeDeclaration(.*?)\\/>/<outcomeDeclaration$1>\n\t<defaultValue>\n\t\t<value>0<\/value>\n\t<\/defaultValue>\n<\/outcomeDeclaration>/g;t' <<< "<assessmentItem xmlns=\"http://www.imsglobal.org/xsd/imsqti_v2p1\" xmlns:m=\"http://www.w3.org/1998/Math/MathML\" xmlns:xi=\"http://www.w3.org/2001/XInclude\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xsi:schemaLocation=\"http://www.imsglobal.org/xsd/imsqti_v2p1 http://www.imsglobal.org/xsd/qti/qtiv2p1/imsqti_v2p1.xsd\" identifier=\"IT0000300\" title=\"IT0000300\" label=\"Item Label\" adaptive=\"false\" timeDependent=\"false\" toolName=\"TAO\" toolVersion=\"3.1.0-sprint23\"> <responseDeclaration identifier=\"_64B7CBD9-8ED4-EC27-D190-BD0751A38A95\" cardinality=\"single\" baseType=\"string\"/> <outcomeDeclaration identifier=\"SCORE\" cardinality=\"single\" baseType=\"float\"> <defaultValue> <value>0</value> </defaultValue> </outcomeDeclaration> <outcomeDeclaration identifier=\"SCORE\" cardinality=\"single\" baseType=\"float\"/> <stylesheet href=\"style/custom/tao-user-styles.css\" type=\"text/css\" media=\"all\" title=\"\"/> <itemBody> <div class=\"grid-row\"> <div class=\"col-12\"><prompt> <p>300</p> </prompt> <extendedTextInteraction responseIdentifier=\"_64B7CBD9-8ED4-EC27-D190-BD0751A38A95\" base=\"10\" minStrings=\"0\" format=\"plain\" class=\"\"> </extendedTextInteraction> </div> </div> </itemBody>"

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