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

/
/

Test String

Code Generator

Language

Generated Code

package main import ( "regexp" "fmt" ) func main() { var re = regexp.MustCompile(`(?:opc.tcp|https|http):\/\/(\S+):\d+[\/\w]*`) var str = `https://198.10.157.14:4814/fdggfh/fdhgdsf/gnhdfg opc.tcp://198.10.157.14:4814/fdggfh/fdhgdsf/gnhdfg address 192.168.1.1 netmask 255.255.255.0 gateway 192.168.1.254 =[\w\W]*(auto[\w\W]*eth2\s+inet\s+(dhcp|static)\s*((?:address\s+\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})\s+(?:netmask\s+\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})\s+(?:gateway\s+(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})))?) auto eth2 iface eth2 inet static address 192.168.1.1 netmask 255.255.255.0 gateway 192.168.1.254 pre-up /sbin/ifconfig $IFACE mtu 1450 auto eth3 iface eth3 inet static address 192.168.1.1 netmask 255.255.255.0 gateway 192.168.1.254 = ([\d\.]+)(\w?)\s+\d+%.* /dev/sda1 ff 55 7sg233 fgd 3.7G 4.0K 3.7G 0% /mnt/sda1 <?xml version="1.0" encoding= "utf-8"?> <confi guration> [\w\W]*(auto[\w\W]*eth2\s+inet\s+(dhcp|static)\s+((?:address\s+\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})?\s*(?:netmask\s+\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})?\s*(?:gateway\s+(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}))?)?\s+(pre-up \/sbin\/ifconfig \$IFACE mtu \d{3,4}\s+))` if len(re.FindStringIndex(str)) > 0 { fmt.Println(re.FindString(str),"found at index",re.FindStringIndex(str)[0]) } }

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 Golang, please visit: https://golang.org/pkg/regexp/