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

/
/
gm

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/(^[%@]\tfor\t)(.*[\w\s:]??)(?![→←].*)(\[sound.*)/\1\2\t\3/gm;t' <<< "% for 1 <i><font color=\"#ab0000\">British English</font></i> to make something seem less successful, interesting, good etc than it really is: [sound:_p008-000614203.mp3] the pessimists who are talking down Britain →贬低英国的悲观主义者 @ for to talk to someone as if they are stupid, although they are not ←以高人一等的口气对〔某人〕说话； <i><font color=\"#efefef\" style=\"background-color: rgb(141, 141, 141);\">SYN</font></i> patronize: [sound:_p008-000614218.mp3] The students felt that they were talked down to as though they were children. →这些学生感到和他们说话的都是一副居高临下的口气，好像他们是小孩一样。 @ for talk somebody into doing something [sound:_p008-000614234.mp3] My husband talked me into going skiing. →我的丈夫说服我去滑雪。 "

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