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
  • Match everything enclosed
    (?:...)
  • Capture everything enclosed
    (...)
  • 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

@
@
xsg

Test String

Substitution

Processing...

Code Generator

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) (?<next_open_tag> [^<]*+ (?i: <++[^<?s][^<]* | <++(?! \?php | \?= | script\s*language\s*=\s*([\'"]?)php\g{-1}\s*> ) [^<]* )*+ (?i: <++(?: \?php | \?= | [^>]+ ) | \z ) ) ) \A (?&next_open_tag) \K | [^'"`\/#<?]*+ (?: '(?:[^'\\]+|\\.)*+' [^\'"`\/#<?]* | "(?:[^"\\]+|\\.)*+" [^\'"`\/#<?]* | `(?:[^`\\]+|\\.)*+` [^\'"`\/#<?]* | \/(?![\/*]) [^\'"`\/#<?]* # stop for \/\/ or \/* | # if close tag ?> \? (?: >(?&next_open_tag)[^\'"`\/#<?]* | ) | < (?: # heredoc or nowdoc <<[\ \t]*([\'"]?) ([a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*) \g{-2}[\ \t]*[\r\n] (?-s:.*+[\r\n])*? \g{-1}[\r\n;] [^\'"`\/#<?]* | (?i: \/script\s*>) (?&next_open_tag) [^\'"`\/#<?]* | [^\'"`\/#<?]* ) )*+ \K (?: (?:\/\/|\#)(?:[^\n?]+|\?(?!>))*+ # single line comment \/\/ и # | \/\*(?:[^*]+|\*(?!\/))*+\*\/ # multi line comment \/* *\/ )? //xsg;t' <<< "<!-- *//* --> <?php $a = \"text */*\"; // comment $b = 'text *//*'; # comment //* if ($a) { echo $b; } /*/ if ($bar) { echo $foo; } // */ ?> <!-- *//* --> <script language = \"php\" > # comment ?> Text <?php $a = '/*'; // comment $b = @`ls ./* -al`; # */ </script> <!-- *//* --> "

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