Replacement Reference

Replacement String Characters

Feature	Syntax	Description	Example	JGsoft	.NET	Java	Perl	PCRE2	PHP	Delphi	R	JavaScript	VBScript	XRegExp	Python	Ruby	std::regex	Boost	Tcl ARE	Oracle	XPath
Backslash	Backslash followed by any character that does not form a token	A backslash that is followed by any character that does not form a replacement string token in combination with the backslash inserts the escaped character literally.	Replacing with `\!` yields `!`	no	no	YES	YES	extended	no	no	YES	no	no	no	3.7–3.10 error	no	sed	YES	no	no	error
Backslash	A backslash that does not form a token	A backslash that is not part of a replacement string token is a literal backslash.	Replacing with `\!` yields `\!`	YES	YES	no	no	default	YES	YES	no	YES	YES	YES	YES	YES	default	no	YES	YES	error
Backslash	Trailing backslash	A backslash at the end of the replacement string is a literal backslash.	Replacing with `\` yields `\`	YES	YES	error	error	default	YES	YES	no	YES	YES	YES	error	YES	default	YES	YES	YES	error
Backslash	`\\`	A backslash escapes itself.	Replacing with `\\` yields `\`	YES	no	YES	YES	extended	YES	YES	YES	no	no	no	YES	YES	sed	YES	YES	YES	YES
Dollar	A dollar that does not form a token	A dollar sign that does not form a replacement string token is a literal dollar sign.	Replacing with `$!` yields `$!`	YES	YES	error	error	error	YES	YES	YES	YES	YES	error	YES	YES	YES	YES	YES	YES	error
Dollar	Trailing dollar	A dollar sign at the end of the replacement string is a literal dollar sign.	Replacing with `$` yields `$`	YES	YES	error	error	error	YES	YES	YES	YES	YES	2–4	YES	YES	default VC’15–VC’22 sed VC’08–VC’22	YES	YES	YES	error
Dollar	`$$`	A dollar sign escapes itself.	Replacing with `$$` yields `$`	YES	YES	error	error	YES	no	YES	no	YES	YES	YES	no	no	default	all default	no	no	error
Dollar	`\$`	A backslash escapes a dollar sign.	Replacing with `\$` yields `$`	YES	no	YES	YES	extended	YES	YES	YES	no	no	no	3.7–3.10 error	no	sed	YES	no	no	YES
Hexadecimal escape	`\xFF` where FF are 2 hexadecimal digits	Inserts the character at the specified position in the code page	`\xA9` inserts `©` when using the Latin-1 code page	YES	no	no	YES	extended	string	no	string	string	no	string	string	string	string	YES	string	no	error
Unicode escape	`\uFFFF` where FFFF are 4 hexadecimal digits	Inserts a specific Unicode code point.	`\u00E0` inserts `à` encoded as U+00E0 only. `\u00A9` inserts `©`	YES	no	string	no	extended error	no	no	string	string	no	string	string	1.9 string	string	no	string	no	error
Unicode escape	`\u{FFFF}` where FFFF are 1 to 4 hexadecimal digits	Inserts a specific Unicode code point.	`\u{E0}` inserts `à` encoded as U+00E0 only. `\u{A9}` inserts `©`	V2	no	no	no	extended error	7.0.0 string	no	string	string	no	string	3.7–3.10 error	1.9 string	no	no	no	no	error
Unicode escape	`\x{FFFF}` where FFFF are 1 to 4 hexadecimal digits	Inserts a specific Unicode code point.	`\x{E0}` inserts `à` encoded as U+00E0 only. `\x{A9}` inserts `©`	YES	no	no	YES	extended	no	no	no	no	no	no	3.7–3.10 error	no	no	YES	no	no	error
Character escape	`\n`, `\r` and `\t`	Insert an LF character, CR character and a tab character respectively	`\r\n` inserts a Windows CRLF line break	YES	no	string	YES	extended	string	no	string	string	no	string	YES	string	string	YES	string	no	error
Character escape	`\a`	Insert the “alert” or “bell” control character (ASCII 0x07)		no	no	no	YES	extended	no	no	no	no	no	no	YES	no	no	YES	no	no	error
Character escape	`\b`	Insert the “backspace” control character (ASCII 0x08)		no	no	no	YES	extended error	no	no	no	no	no	no	YES	no	no	no	no	no	error
Character escape	`\e`	Insert the “escape” control character (ASCII 0x1B)		no	no	no	YES	extended	no	no	no	no	no	no	3.7–3.10 error	no	no	YES	no	no	error
Character escape	`\f`	Insert the “form feed” control character (ASCII 0x0C)		no	no	no	YES	extended	no	no	no	no	no	no	YES	no	no	YES	no	no	error
Character escape	`\v`	Insert the “vertical tab” control character (ASCII 0x0B)		no	no	no	no	extended error	no	no	no	no	no	no	YES	no	no	YES	no	no	error
Control character escape	`\cA` through `\cZ`	Insert an ASCII character Control+A through Control+Z, equivalent to `\x01` through `\x1A`	`\cM\cJ` inserts a Windows CRLF line break	no	no	no	YES	extended	no	no	no	no	no	no	no	no	no	YES	no	no	no
Control character escape	`\ca` through `\cz`	Insert an ASCII character Control+A through Control+Z, equivalent to `\x01` through `\x1A`	`\cm\cj` inserts a Windows CRLF line break	no	no	no	YES	extended	no	no	no	no	no	no	no	no	no	YES	no	no	no
NULL escape	`\0`	Insert the NULL character		no	no	no	YES	extended error	no	no	no	no	no	no	YES	no	no	all default	no	no	error
Octal escape	`\o{7777}` where 7777 is any octal number	Inserts the character at the specified position in the active code page	`\o{20254}` inserts `€` when using Unicode	V2	no	no	5.14	extended	no	no	no	no	no	no	3.7–3.10 error	no	no	no	no	no	error
Octal escape	`\10` through `\77`	Inserts the character at the specified position in the ASCII table	`\77` inserts `?`	no	no	no	YES	extended error	no	no	no	no	no	no	no	no	no	no	no	no	error
Octal escape	`\100` through `\177`	Inserts the character at the specified position in the ASCII table	`\100` inserts `@`	no	no	no	YES	extended error	no	no	no	no	no	no	YES	no	no	no	no	no	error
Octal escape	`\200` through `\377`	Inserts the character at the specified position in the active code page	`\377` inserts `ÿ` when using the Latin-1 code page	no	no	no	YES	extended error	no	no	no	no	no	no	YES	no	no	no	no	no	error
Octal escape	`\400` through `\777`	Inserts the character at the specified position in the active code page	`\777` inserts `ǿ` when using Unicode	no	no	no	YES	extended error	no	no	no	no	no	no	no	no	no	no	no	no	error
Octal escape	`\01` through `\07`	Inserts the character at the specified position in the ASCII table	`\07` inserts the “bell” character	no	no	no	YES	extended error	no	no	no	no	no	no	YES	no	no	all default	no	no	error
Octal escape	`\010` through `\077`	Inserts the character at the specified position in the ASCII table	`\077` inserts `?`	no	no	no	YES	extended error	no	no	no	no	no	no	YES	no	no	all default	no	no	error
Feature	Syntax	Description	Example	JGsoft	.NET	Java	Perl	PCRE2	PHP	Delphi	R	JavaScript	VBScript	XRegExp	Python	Ruby	std::regex	Boost	Tcl ARE	Oracle	XPath