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]
  • Character class intersection
    [\w&&[^\d]]
  • 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

re = /^(\/.*)\n(.+)\n*|(?<=^(\/.*)\n(?:.+\n)*)(.+)\n*/m str = 'こんにちは 質問です ●Regular Expressionの使用環境 普通のテキストファイル いま Sublime text を使ってますが無料のエディタなら何でも使います ●検索か置換か？ 置換 ●説明 各パラグラフの1行目を２行目以下の全ての行に加えたい １行目はパラグラフごとに異なり、２行目以下はすべて異なる ●対象データ /system/app AntHalService AutoRegistration BasicDreams /system/priv-app AutoKillService BackupRestoreConfirmation ●希望する結果 AntHalService＾=/system/app/AntHalService AutoRegistration＾=/system/app/AutoRegistration BasicDreams＾=/system/app/BasicDreams AutoKillService＾=/system/priv-app/AutoKillService BackupRestoreConfirmation＾=/system/priv-app/BackupRestoreConfirmation よろしくお願いします' subst = '$2$4＾=$1$3/$2$4\\n' result = str.gsub(re, subst) # Print the result of the substitution puts result

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 Ruby, please visit: http://ruby-doc.org/core-2.2.0/Regexp.html