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

~
~
gsixuX

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/(?(DEFINE) (?<tagName> [a-z][a-z\d]*+ (?=[>\s\/]) ) (?<tagAttr> (?> [^>"']++ | " [^"]*+ " | ' [^']*+ ' )*+ ) ) < (li|\/ul) \/?+ (?=[>\s\/]) ((?&tagAttr)) > ((?: [^<]++ | < \/?+ (?!(?:li|ul)(?=[>\s\/])) (?&tagName) (?&tagAttr) > #any tag except <li> and <ul> | < (?! \/?+ (?&tagName) ) #not tag )*) (?= < (?:li|\/ul) (?=[>\s\/]) (?&tagAttr) ) #check for nested <li> and <ul>/<$3$4>$5<\/LI>\r/gsixuX;t' <<< "<ul> <li fhgfhfg ghgfhfghhfgh= ghghg=\"...\" a = 'ghghg'>dfdsfsd <ul> <li>111</li> <li/>2222 <li>mmmmm</li> </ul> <li>dfdsfdsfsdf <b class=\"...\"><br/>fgdfgd<i></b><!-- dfdf--><li> <li> <li>dsfsdfsdfdsf </ul> "

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