Merge from existing archive branch

[pcre3.git] / doc / html / pcrepattern.html

diff --git a/doc/html/pcrepattern.html b/doc/html/pcrepattern.html
index c06d1e03f11665068820e9c4232bd702e4f88963..55034a7edf6ad83f0084a412f07d3de611dfa333 100644 (file)
--- a/doc/html/pcrepattern.html
+++ b/doc/html/pcrepattern.html
@@ -329,7 +329,8 @@ A second use of backslash provides a way of encoding non-printing characters
 in patterns in a visible manner. There is no restriction on the appearance of
 non-printing characters, apart from the binary zero that terminates a pattern,
 but when a pattern is being prepared by text editing, it is often easier to use
-one of the following escape sequences than the binary character it represents:
+one of the following escape sequences than the binary character it represents.
+In an ASCII or Unicode environment, these escapes are as follows:
 <pre>
   \a        alarm, that is, the BEL character (hex 07)
   \cx       "control-x", where x is any ASCII character
@@ -353,19 +354,33 @@ data item (byte or 16-bit value) following \c has a value greater than 127, a
 compile-time error occurs. This locks out non-ASCII characters in all modes.
 </P>
 <P>
-The \c facility was designed for use with ASCII characters, but with the
-extension to Unicode it is even less useful than it once was. It is, however,
-recognized when PCRE is compiled in EBCDIC mode, where data items are always
-bytes. In this mode, all values are valid after \c. If the next character is a
-lower case letter, it is converted to upper case. Then the 0xc0 bits of the
-byte are inverted. Thus \cA becomes hex 01, as in ASCII (A is C1), but because
-the EBCDIC letters are disjoint, \cZ becomes hex 29 (Z is E9), and other
-characters also generate different values.
+When PCRE is compiled in EBCDIC mode, \a, \e, \f, \n, \r, and \t
+generate the appropriate EBCDIC code values. The \c escape is processed
+as specified for Perl in the <b>perlebcdic</b> document. The only characters
+that are allowed after \c are A-Z, a-z, or one of @, [, \, ], ^, _, or ?. Any
+other character provokes a compile-time error. The sequence \@ encodes
+character code 0; the letters (in either case) encode characters 1-26 (hex 01
+to hex 1A); [, \, ], ^, and _ encode characters 27-31 (hex 1B to hex 1F), and
+\? becomes either 255 (hex FF) or 95 (hex 5F).
+</P>
+<P>
+Thus, apart from \?, these escapes generate the same character code values as
+they do in an ASCII environment, though the meanings of the values mostly
+differ. For example, \G always generates code value 7, which is BEL in ASCII
+but DEL in EBCDIC.
+</P>
+<P>
+The sequence \? generates DEL (127, hex 7F) in an ASCII environment, but
+because 127 is not a control character in EBCDIC, Perl makes it generate the
+APC character. Unfortunately, there are several variants of EBCDIC. In most of
+them the APC character has the value 255 (hex FF), but in the one Perl calls
+POSIX-BC its value is 95 (hex 5F). If certain other characters have POSIX-BC
+values, PCRE makes \? generate 95; otherwise it generates 255.
 </P>
 <P>
 After \0 up to two further octal digits are read. If there are fewer than two
-digits, just those that are present are used. Thus the sequence \0\x\07
-specifies two binary zeros followed by a BEL character (code value 7). Make
+digits, just those that are present are used. Thus the sequence \0\x\015
+specifies two binary zeros followed by a CR character (code value 13). Make
 sure you supply two digits after the initial zero if the pattern character that
 follows is itself an octal digit.
 </P>
@@ -703,6 +718,7 @@ Armenian,
 Avestan,
 Balinese,
 Bamum,
+Bassa_Vah,
 Batak,
 Bengali,
 Bopomofo,
@@ -712,6 +728,7 @@ Buginese,
 Buhid,
 Canadian_Aboriginal,
 Carian,
+Caucasian_Albanian,
 Chakma,
 Cham,
 Cherokee,
@@ -722,11 +739,14 @@ Cypriot,
 Cyrillic,
 Deseret,
 Devanagari,
+Duployan,
 Egyptian_Hieroglyphs,
+Elbasan,
 Ethiopic,
 Georgian,
 Glagolitic,
 Gothic,
+Grantha,
 Greek,
 Gujarati,
 Gurmukhi,
@@ -746,40 +766,56 @@ Katakana,
 Kayah_Li,
 Kharoshthi,
 Khmer,
+Khojki,
+Khudawadi,
 Lao,
 Latin,
 Lepcha,
 Limbu,
+Linear_A,
 Linear_B,
 Lisu,
 Lycian,
 Lydian,
+Mahajani,
 Malayalam,
 Mandaic,
+Manichaean,
 Meetei_Mayek,
+Mende_Kikakui,
 Meroitic_Cursive,
 Meroitic_Hieroglyphs,
 Miao,
+Modi,
 Mongolian,
+Mro,
 Myanmar,
+Nabataean,
 New_Tai_Lue,
 Nko,
 Ogham,
+Ol_Chiki,
 Old_Italic,
+Old_North_Arabian,
+Old_Permic,
 Old_Persian,
 Old_South_Arabian,
 Old_Turkic,
-Ol_Chiki,
 Oriya,
 Osmanya,
+Pahawh_Hmong,
+Palmyrene,
+Pau_Cin_Hau,
 Phags_Pa,
 Phoenician,
+Psalter_Pahlavi,
 Rejang,
 Runic,
 Samaritan,
 Saurashtra,
 Sharada,
 Shavian,
+Siddham,
 Sinhala,
 Sora_Sompeng,
 Sundanese,
@@ -797,8 +833,10 @@ Thaana,
 Thai,
 Tibetan,
 Tifinagh,
+Tirhuta,
 Ugaritic,
 Vai,
+Warang_Citi,
 Yi.
 </P>
 <P>
@@ -3226,9 +3264,9 @@ Cambridge CB2 3QH, England.
 </P>
 <br><a name="SEC30" href="#TOC1">REVISION</a><br>
 <P>
-Last updated: 08 January 2014
+Last updated: 14 June 2015
 <br>
-Copyright &copy; 1997-2014 University of Cambridge.
+Copyright &copy; 1997-2015 University of Cambridge.
 <br>
 <p>
 Return to the <a href="index.html">PCRE index page</a>.