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

/
/
gms

Test String

Code Generator

Generated Code

import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String[] args) { final String regex = "(?<text>N?'((?:''|[^'])*)'|N?\"((?:\"\"|[^\"])*)\")"; final String string = "USE [master]\n" + "GO\n\n" + "IF OBJECT_ID('dbo.sp_foreach_db') IS NOT NULL\n" + " DROP PROCEDURE [dbo].[sp_foreach_db] \n" + "GO\n\n" + "CREATE PROCEDURE [dbo].[sp_foreach_db] \n" + "(\n" + " @tsql NVARCHAR(MAX) = NULL\n" + " ,@replacedatabasenamepattern NVARCHAR(20) = N'?'\n\n" + " ,@break_on_error BIT = 1\n\n" + " ,@db_name_like NVARCHAR(128) = NULL\n" + " ,@db_name_in NVARCHAR(4000) = NULL\n" + " ,@db_name_not_in NVARCHAR(4000) = NULL\n" + " ,@db_use_system_db BIT = 0\n" + " ,@db_use_temp_db BIT = 0\n\n" + " ,@push_info_msg BIT = 1\n" + ")\n" + "WITH EXECUTE AS CALLER \n" + "AS\n" + "/*\n" + "Version: 1.0.1.0\n" + "Developer: Paw Jershauge\n" + "Created: 18-03-2016 13:01:00\n" + "*/\n" + "BEGIN\n" + " IF @tsql IS NULL\n" + " RETURN 0;\n" + " \n" + " SET NOCOUNT ON;\n" + " DECLARE @dbtsql NVARCHAR(MAX)\n" + " ,@firecode NVARCHAR(MAX)\n" + " ,@db_name NVARCHAR(128)\n" + " ,@dbnames NVARCHAR(MAX) = N''\n" + " ,@has_replacement BIT = 0\n" + " ,@msg_str NVARCHAR(2044)\n\n" + " SET @dbtsql = N'SELECT @dbnames += [name] + CHAR(10) FROM [master].[sys].[databases] WHERE [state] = 0'\n" + " SET @dbtsql += IIF(ISNULL(@db_use_temp_db, 0) = 1, N'', N' AND [database_id] <> 2')\n" + " SET @dbtsql += IIF(ISNULL(@db_use_system_db, 0) = 1, N'', N' AND [database_id] > 4')\n" + " SET @dbtsql += IIF(NULLIF(@db_name_like, N'') IS NULL, N'', N' AND [name] LIKE ''' + @db_name_like + N'''')\n" + " SET @dbtsql += IIF(NULLIF(@db_name_in, N'') IS NULL, N'', N' AND [name] IN (' + @db_name_in + N')')\n" + " SET @dbtsql += IIF(NULLIF(@db_name_not_in, N'') IS NULL, N'', N' AND [name] NOT IN (' + @db_name_not_in + N')')\n" + " \n" + " EXEC sp_executesql @dbtsql, N'@dbnames NVARCHAR(MAX) OUTPUT', @dbnames = @dbnames OUTPUT;\n\n" + " SELECT @has_replacement = CAST(CHARINDEX(ISNULL(@replacedatabasenamepattern, N'?'), @tsql) AS BIT)\n" + " \n" + " DECLARE cur_db CURSOR LOCAL FORWARD_ONLY FAST_FORWARD READ_ONLY FOR SELECT [value] FROM STRING_SPLIT(@dbnames, CHAR(10)) WHERE [value] <> N'' ORDER BY [value]\n" + " OPEN cur_db\n" + " FETCH NEXT FROM cur_db INTO @db_name\n" + " WHILE @@FETCH_STATUS = 0 \n" + " BEGIN \n" + " BEGIN TRY\n" + " SELECT @firecode = N'EXEC (N''' + IIF(@has_replacement = 0,N'Use [' + @db_name + N']; ', N'') + REPLACE(REPLACE(@tsql, ISNULL(@replacedatabasenamepattern, N'?'), @db_name), N'''', N'''''') + N''')'\n" + " \n" + " IF @push_info_msg = 1\n" + " BEGIN\n" + " SET @msg_str = CONVERT(NVARCHAR(40),GETDATE(), 121) + N':Executing on ' + @db_name\n" + " RAISERROR (@msg_str, 0, 1) WITH NOWAIT\n" + " END\n" + " EXEC sp_executesql @firecode\n" + " IF @push_info_msg = 1\n" + " BEGIN\n" + " SET @msg_str = CONVERT(NVARCHAR(40),GETDATE(), 121) + N':' + @db_name + N' Done!'\n" + " RAISERROR (@msg_str, 0, 1) WITH NOWAIT\n" + " END\n" + " END TRY\n" + " BEGIN CATCH\n" + " SET @msg_str = 'Database ' + @db_name + ' failed with the following message:'\n" + " RAISERROR (@msg_str, 0, 1) WITH NOWAIT\n" + " SET @msg_str = ERROR_MESSAGE()\n" + " RAISERROR (@msg_str, 0, 1) WITH NOWAIT --Workaround of the PRINT Command that is stacked and released in reverse order, on remote servers\n\n" + " IF @break_on_error = 1\n" + " THROW\n" + " END CATCH\n\n" + " FETCH NEXT FROM cur_db INTO @db_name\n" + " END\n" + " CLOSE cur_db\n" + " DEALLOCATE cur_db\n\n" + "END\n" + "GO\n\n" + "EXEC sys.sp_MS_marksystemobject sp_foreach_db\n" + "GO"; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE | Pattern.DOTALL); final Matcher matcher = pattern.matcher(string); while (matcher.find()) { System.out.println("Full match: " + matcher.group(0)); for (int i = 1; i <= matcher.groupCount(); i++) { System.out.println("Group " + i + ": " + matcher.group(i)); } } } }

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 Java, please visit: https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html