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Diffstat (limited to 'doc/pcre2syntax.3')
| -rw-r--r-- | doc/pcre2syntax.3 | 29 |
1 files changed, 18 insertions, 11 deletions
diff --git a/doc/pcre2syntax.3 b/doc/pcre2syntax.3 index ff1b2b8..b6dd33c 100644 --- a/doc/pcre2syntax.3 +++ b/doc/pcre2syntax.3 @@ -1,4 +1,4 @@ -.TH PCRE2SYNTAX 3 "03 February 2019" "PCRE2 10.33" +.TH PCRE2SYNTAX 3 "11 February 2019" "PCRE2 10.33" .SH NAME PCRE2 - Perl-compatible regular expressions (revised API) .SH "PCRE2 REGULAR EXPRESSION SYNTAX SUMMARY" @@ -22,7 +22,8 @@ documentation. This document contains a quick-reference summary of the syntax. .SH "ESCAPED CHARACTERS" .rs .sp -This table applies to ASCII and Unicode environments. +This table applies to ASCII and Unicode environments. An unrecognized escape +sequence causes an error. .sp \ea alarm, that is, the BEL character (hex 07) \ecx "control-x", where x is any ASCII printing character @@ -34,12 +35,24 @@ This table applies to ASCII and Unicode environments. \e0dd character with octal code 0dd \eddd character with octal code ddd, or backreference \eo{ddd..} character with octal code ddd.. - \eU "U" if PCRE2_ALT_BSUX is set (otherwise is an error) \eN{U+hh..} character with Unicode code point hh.. (Unicode mode only) - \euhhhh character with hex code hhhh (if PCRE2_ALT_BSUX is set) \exhh character with hex code hh \ex{hh..} character with hex code hh.. .sp +If PCRE2_ALT_BSUX or PCRE2_EXTRA_ALT_BSUX is set ("ALT_BSUX mode"), the +following are also recognized: +.sp + \eU the character "U" + \euhhhh character with hex code hhhh + \eu{hh..} character with hex code hh.. but only for EXTRA_ALT_BSUX +.sp +When \ex is not followed by {, from zero to two hexadecimal digits are read, +but in ALT_BSUX mode \ex must be followed by two hexadecimal digits to be +recognized as a hexadecimal escape; otherwise it matches a literal "x". +Likewise, if \eu (in ALT_BSUX mode) is not followed by four hexadecimal digits +or (in EXTRA_ALT_BSUX mode) a sequence of hex digits in curly brackets, it +matches a literal "u". +.P Note that \e0dd is always an octal code. The treatment of backslash followed by a non-zero digit is complicated; for details see the section .\" HTML <a href="pcre2pattern.html#digitsafterbackslash"> @@ -54,12 +67,6 @@ documentation, where details of escape processing in EBCDIC environments are also given. \eN{U+hh..} is synonymous with \ex{hh..} in PCRE2 but is not supported in EBCDIC environments. Note that \eN not followed by an opening curly bracket has a different meaning (see below). -.P -When \ex is not followed by {, from zero to two hexadecimal digits are read, -but if PCRE2_ALT_BSUX is set, \ex must be followed by two hexadecimal digits to -be recognized as a hexadecimal escape; otherwise it matches a literal "x". -Likewise, if \eu (in ALT_BSUX mode) is not followed by four hexadecimal digits, -it matches a literal "u". . . .SH "CHARACTER TYPES" @@ -647,6 +654,6 @@ Cambridge, England. .rs .sp .nf -Last updated: 03 February 2019 +Last updated: 11 February 2019 Copyright (c) 1997-2019 University of Cambridge. .fi |