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

/
/
mgi

Test String

Code Generator

Language

Generated Code

import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String[] args) { final String regex = "^(?!\\s*$)\\s*(?!\\s)([^#\\n\\[=]+?)\\s*?(?>#.*?$|(?>=\\s*$|=\\s*?(?:#?|(\".*?\"|[^\\s].*?)\\s*?)(?:\\s*#.*?$)*?$)?$)"; final String string = "[mysqld]\n" + "skip-grant-tables # k\n" + "bind-address=127.0.0.1\n" + " port = 3307 # test \n" + "basedir=C:\\Program Files (x86)\\MySQL\\ \n" + "datadir=C:\\Program Files (x86)\\MySQL\\data\\\n\n" + "default-storage-engine=INNODB \n\n" + "sql-mode= \" STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER,test NO_ENGINE_SUBSTITUTION\" #test\n\n" + "max_connections=1000\n\n" + "tmp_table_size=1G\n" + "max_heap_table_size=1G\n" + "join_buffer_size=1M \n" + "query_cache_size =50M\n" + "query_cache_limit=50M\n" + "max_allowed_packet = 104857600\n" + "port =\n\n" + " = fh\n" + "thread_cache_size=8\n\n" + "#*** MyISAM Specific options\n\n" + "myisam_max_sort_file_size=100G\n" + "myisam_sort_buffer_size=35M\n" + "key_buffer_size=25M\n" + "read_buffer_size=64K\n" + "read_rnd_buffer_size=256K\n" + "sort_buffer_size=256K\n\n" + "#*** INNODB Specific options ***\n\n" + "innodb_flush_log_at_trx_commit=0\n" + "innodb_log_buffer_size=50M\n" + "innodb_buffer_pool_size=1000M\n" + "innodb_log_file_size=300M\n" + "innodb_thread_concurrency=8\n" + "innodb_flush_method=normal\n" + "innodb_autoinc_lock_mode=0 \n\n\n" + "test=0\n"; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE | Pattern.CASE_INSENSITIVE); 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