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Regular Expression Reference: Basic Features

FeatureSyntaxDescriptionExampleJGsoft Python JavaScript VBScript XRegExp .NET Java ICU RE2 Perl PCRE PCRE2 PHP Delphi R Ruby std::regex Boost Tcl POSIX GNU Oracle XML XPath
Dot . (dot) Matches any single character except line break characters. Most regex flavors have an option to make the dot match line break characters too. . matches x or (almost) any other character YESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYES
Not a line break \N Matches any single character except line break characters, like the dot, but is not affected by any options that make the dot match all characters including line breaks. \N matches x or any other character that is not a line break V2nonononononononoYES8.10YESYESXE7YESnonononononononono
Alternation | (pipe) Causes the regex engine to match either the part on the left side, or the part on the right side. Can be strung together into a series of alternatives. abc|def|xyz matches abc, def or xyz YESYESYESYESYESYESYESYESYESYESYESYESYESYESYESYESECMA
extended
egrep
awk
ECMA
extended
egrep
awk
YESextendedextendedYESYESYES
Alternation \| (backslash pipe) Causes the regex engine to match either the part on the left side, or the part on the right side. Can be strung together into a series of alternatives. abc\|def\|xyz matches abc, def or xyz nonononononononononononononononononononobasicnonono
Alternation Literal line feed not inside a group or character class Causes the regex engine to match either the part on the left side, or the part on the right side. Can be strung together into a series of alternatives. abc def xyz matches abc, def or xyz nonononononononononononononononogrep
egrep
grep
egrep
nononononono
Alternation Literal line feed inside a group but not inside a character class Causes the group to match either the part on the left side, or the part on the right side. Can be strung together into a series of alternatives. a(bc de fg)h matches abch, adeh or afgh nononononononononononononononononogrep
egrep
nononononono
Alternation is eager | or \| Alternation returns the first alternative that matches. a|ab matches a in ab YESYESYESYESYESYESYESYESoptionYESYESYESYESYESYESYESECMAECMAnononoYESYESYES
Alternation is greedy | or \| Alternation returns the longest alternative that matches. a|ab matches ab in ab nonononononononooptionnononononononoextended
grep
egrep
awk
extended
grep
egrep
awk
YESextendedYESnonono
FeatureSyntaxDescriptionExampleJGsoft Python JavaScript VBScript XRegExp .NET Java ICU RE2 Perl PCRE PCRE2 PHP Delphi R Ruby std::regex Boost Tcl POSIX GNU Oracle XML XPath

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