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

Code Generator

Language

Generated Code

package main import ( "regexp" "fmt" ) func main() { var re = regexp.MustCompile(`(?m)(.*[[:space:]]GRAVE:.*)`) var str = `INFORMAZIONI: Parsing jar:file:/workarea/apache-tomcat/apache-tomcat-7.0.47_GA/webapps/GestioneAutorizzazioni/WEB-INF/lib/zkex-6.5.6.jar!/metainfo/zk/zk.xml lug 26, 2022 10:30:25 PM org.zkoss.zk.ui.sys.ConfigParser parse:269 INFORMAZIONI: Parsing jar:file:/workarea/apache-tomcat/apache-tomcat-7.0.47_GA/webapps/GestioneAutorizzazioni/WEB-INF/lib/zkmax-6.5.6.jar!/metainfo/zk/zk.xml lug 26, 2022 10:30:25 PM org.zkoss.zk.ui.sys.ConfigParser parse:269 INFORMAZIONI: Parsing jndi:/localhost/GestioneAutorizzazioni/WEB-INF/zk.xml lug 26, 2022 10:30:25 PM org.zkoss.zk.ui.http.WebManager <init>:172 INFORMAZIONI: Parsing file:///workarea/apache-tomcat/tomcatGA/confapps/GestioneAutorizzazioni/zk-production.xml lug 26, 2022 10:30:25 PM org.zkoss.zk.ui.http.WebManager <init>:179 GRAVE: File not found: file:///workarea/apache-tomcat/tomcatGA/confapps/GestioneAutorizzazioni/zk-production.xml lug 26, 2022 10:30:26 PM org.zkoss.zk.ui.metainfo.DefinitionLoaders parseLang:410 AVVERTENZA: Component jasperreport ignored. Reason: unable to load org.zkoss.zkex.zul.Jasperreport due to java.lang.NoClassDefFoundError: net/sf/jasperreports/engine/JRDataSource Configuring Spring Security Core ... ... finished configuring Spring Security Core amministrazione-database: doWithSpring anagrafe-soggetti: doWithSpring struttura-organizzativa: doWithSpring AmministrazioneDatabaseBootStrap: validate lug 26, 2022 10:30:56 PM org.apache.catalina.startup.HostConfig deployWAR INFORMAZIONI: Deploying web application archive /workarea/apache-tomcat/apache-tomcat-7.0.47_GA/webapps/probe.war lug 26, 2022 10:30:58 PM org.apache.catalina.startup.HostConfig deployWAR ` for i, match := range re.FindAllString(str, -1) { fmt.Println(match, "found at index", 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 Golang, please visit: https://golang.org/pkg/regexp/