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-rw-r--r--libs/Pcre16/docs/doc/html/pcrepattern.html83
1 files changed, 62 insertions, 21 deletions
diff --git a/libs/Pcre16/docs/doc/html/pcrepattern.html b/libs/Pcre16/docs/doc/html/pcrepattern.html
index c06d1e03f1..96fc72986f 100644
--- a/libs/Pcre16/docs/doc/html/pcrepattern.html
+++ b/libs/Pcre16/docs/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 \c@ encodes
+character code 0; after \c 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 \c? becomes either 255 (hex FF) or 95 (hex 5F).
+</P>
+<P>
+Thus, apart from \c?, 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, \cG always generates code value 7, which is BEL in ASCII
+but DEL in EBCDIC.
+</P>
+<P>
+The sequence \c? 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 \c? 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>
@@ -1474,13 +1512,8 @@ J, U and X respectively.
<P>
When one of these option changes occurs at top level (that is, not inside
subpattern parentheses), the change applies to the remainder of the pattern
-that follows. If the change is placed right at the start of a pattern, PCRE
-extracts it into the global options (and it will therefore show up in data
-extracted by the <b>pcre_fullinfo()</b> function).
-</P>
-<P>
-An option change within a subpattern (see below for a description of
-subpatterns) affects only that part of the subpattern that follows it, so
+that follows. An option change within a subpattern (see below for a description
+of subpatterns) affects only that part of the subpattern that follows it, so
<pre>
(a(?i)b)c
</pre>
@@ -2122,6 +2155,14 @@ capturing is carried out only for positive assertions. (Perl sometimes, but not
always, does do capturing in negative assertions.)
</P>
<P>
+WARNING: If a positive assertion containing one or more capturing subpatterns
+succeeds, but failure to match later in the pattern causes backtracking over
+this assertion, the captures within the assertion are reset only if no higher
+numbered captures are already set. This is, unfortunately, a fundamental
+limitation of the current implementation, and as PCRE1 is now in
+maintenance-only status, it is unlikely ever to change.
+</P>
+<P>
For compatibility with Perl, assertion subpatterns may be repeated; though
it makes no sense to assert the same thing several times, the side effect of
capturing parentheses may occasionally be useful. In practice, there only three
@@ -3226,9 +3267,9 @@ Cambridge CB2 3QH, England.
</P>
<br><a name="SEC30" href="#TOC1">REVISION</a><br>
<P>
-Last updated: 08 January 2014
+Last updated: 23 October 2016
<br>
-Copyright &copy; 1997-2014 University of Cambridge.
+Copyright &copy; 1997-2016 University of Cambridge.
<br>
<p>
Return to the <a href="index.html">PCRE index page</a>.