Documentation update

This commit is contained in:
Philip.Hazel 2021-04-28 15:37:48 +00:00
parent 85fc061dcf
commit a5d81d06f4
6 changed files with 189 additions and 159 deletions

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@ -40,7 +40,11 @@ GENERIC INSTRUCTIONS FOR THE PCRE2 C LIBRARY
The following are generic instructions for building the PCRE2 C library "by The following are generic instructions for building the PCRE2 C library "by
hand". If you are going to use CMake, this section does not apply to you; you hand". If you are going to use CMake, this section does not apply to you; you
can skip ahead to the CMake section. can skip ahead to the CMake section. Note that the settings concerned with
8-bit, 16-bit, and 32-bit code units relate to the type of data string that
PCRE2 processes. They are NOT referring to the underlying operating system bit
width. You do not have to do anything special to compile in a 64-bit
environment, for example.
(1) Copy or rename the file src/config.h.generic as src/config.h, and edit the (1) Copy or rename the file src/config.h.generic as src/config.h, and edit the
macro settings that it contains to whatever is appropriate for your macro settings that it contains to whatever is appropriate for your
@ -86,11 +90,11 @@ can skip ahead to the CMake section.
The tables in src/pcre2_chartables.c are defaults. The caller of PCRE2 can The tables in src/pcre2_chartables.c are defaults. The caller of PCRE2 can
specify alternative tables at run time. specify alternative tables at run time.
(4) For an 8-bit library, compile the following source files from the src (4) For a library that supports 8-bit code units in the character strings that
directory, setting -DPCRE2_CODE_UNIT_WIDTH=8 as a compiler option. Also it processes, compile the following source files from the src directory,
set -DHAVE_CONFIG_H if you have set up src/config.h with your setting -DPCRE2_CODE_UNIT_WIDTH=8 as a compiler option. Also set
configuration, or else use other -D settings to change the configuration -DHAVE_CONFIG_H if you have set up src/config.h with your configuration,
as required. or else use other -D settings to change the configuration as required.
pcre2_auto_possess.c pcre2_auto_possess.c
pcre2_chartables.c pcre2_chartables.c
@ -142,9 +146,9 @@ can skip ahead to the CMake section.
If your system has static and shared libraries, you may have to do this If your system has static and shared libraries, you may have to do this
once for each type. once for each type.
(6) If you want to build a 16-bit library or 32-bit library (as well as, or (6) If you want to build a library that supports 16-bit or 32-bit code units,
instead of the 8-bit library) just supply 16 or 32 as the value of (as well as, or instead of the 8-bit library) just supply 16 or 32 as the
-DPCRE2_CODE_UNIT_WIDTH when you are compiling. value of -DPCRE2_CODE_UNIT_WIDTH when you are compiling.
(7) If you want to build the POSIX wrapper functions (which apply only to the (7) If you want to build the POSIX wrapper functions (which apply only to the
8-bit library), ensure that you have the src/pcre2posix.h file and then 8-bit library), ensure that you have the src/pcre2posix.h file and then
@ -401,6 +405,6 @@ Everything in that location, source and executable, is in EBCDIC and native
z/OS file formats. The port provides an API for LE languages such as COBOL and z/OS file formats. The port provides an API for LE languages such as COBOL and
for the z/OS and z/VM versions of the Rexx languages. for the z/OS and z/VM versions of the Rexx languages.
============================== ===========================
Last Updated: 14 November 2018 Last Updated: 28 April 2021
============================== ===========================

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@ -40,7 +40,11 @@ GENERIC INSTRUCTIONS FOR THE PCRE2 C LIBRARY
The following are generic instructions for building the PCRE2 C library "by The following are generic instructions for building the PCRE2 C library "by
hand". If you are going to use CMake, this section does not apply to you; you hand". If you are going to use CMake, this section does not apply to you; you
can skip ahead to the CMake section. can skip ahead to the CMake section. Note that the settings concerned with
8-bit, 16-bit, and 32-bit code units relate to the type of data string that
PCRE2 processes. They are NOT referring to the underlying operating system bit
width. You do not have to do anything special to compile in a 64-bit
environment, for example.
(1) Copy or rename the file src/config.h.generic as src/config.h, and edit the (1) Copy or rename the file src/config.h.generic as src/config.h, and edit the
macro settings that it contains to whatever is appropriate for your macro settings that it contains to whatever is appropriate for your
@ -86,11 +90,11 @@ can skip ahead to the CMake section.
The tables in src/pcre2_chartables.c are defaults. The caller of PCRE2 can The tables in src/pcre2_chartables.c are defaults. The caller of PCRE2 can
specify alternative tables at run time. specify alternative tables at run time.
(4) For an 8-bit library, compile the following source files from the src (4) For a library that supports 8-bit code units in the character strings that
directory, setting -DPCRE2_CODE_UNIT_WIDTH=8 as a compiler option. Also it processes, compile the following source files from the src directory,
set -DHAVE_CONFIG_H if you have set up src/config.h with your setting -DPCRE2_CODE_UNIT_WIDTH=8 as a compiler option. Also set
configuration, or else use other -D settings to change the configuration -DHAVE_CONFIG_H if you have set up src/config.h with your configuration,
as required. or else use other -D settings to change the configuration as required.
pcre2_auto_possess.c pcre2_auto_possess.c
pcre2_chartables.c pcre2_chartables.c
@ -142,9 +146,9 @@ can skip ahead to the CMake section.
If your system has static and shared libraries, you may have to do this If your system has static and shared libraries, you may have to do this
once for each type. once for each type.
(6) If you want to build a 16-bit library or 32-bit library (as well as, or (6) If you want to build a library that supports 16-bit or 32-bit code units,
instead of the 8-bit library) just supply 16 or 32 as the value of (as well as, or instead of the 8-bit library) just supply 16 or 32 as the
-DPCRE2_CODE_UNIT_WIDTH when you are compiling. value of -DPCRE2_CODE_UNIT_WIDTH when you are compiling.
(7) If you want to build the POSIX wrapper functions (which apply only to the (7) If you want to build the POSIX wrapper functions (which apply only to the
8-bit library), ensure that you have the src/pcre2posix.h file and then 8-bit library), ensure that you have the src/pcre2posix.h file and then
@ -401,6 +405,6 @@ Everything in that location, source and executable, is in EBCDIC and native
z/OS file formats. The port provides an API for LE languages such as COBOL and z/OS file formats. The port provides an API for LE languages such as COBOL and
for the z/OS and z/VM versions of the Rexx languages. for the z/OS and z/VM versions of the Rexx languages.
============================== ===========================
Last Updated: 14 November 2018 Last Updated: 28 April 2021
============================== ===========================

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@ -38,8 +38,14 @@ Oniguruma syntax items, and there are options for requesting some minor changes
that give better ECMAScript (aka JavaScript) compatibility. that give better ECMAScript (aka JavaScript) compatibility.
</P> </P>
<P> <P>
The source code for PCRE2 can be compiled to support 8-bit, 16-bit, or 32-bit The source code for PCRE2 can be compiled to support strings of 8-bit, 16-bit,
code units, which means that up to three separate libraries may be installed. or 32-bit code units, which means that up to three separate libraries may be
installed, one for each code unit size. The size of code unit is not related to
the bit size of the underlying hardware. In a 64-bit environment that also
supports 32-bit applications, versions of PCRE2 that are compiled in both
64-bit and 32-bit modes may be needed.
</P>
<P>
The original work to extend PCRE to 16-bit and 32-bit code units was done by The original work to extend PCRE to 16-bit and 32-bit code units was done by
Zoltan Herczeg and Christian Persch, respectively. In all three cases, strings Zoltan Herczeg and Christian Persch, respectively. In all three cases, strings
can be interpreted either as one character per code unit, or as UTF-encoded can be interpreted either as one character per code unit, or as UTF-encoded
@ -198,9 +204,9 @@ use my two initials, followed by the two digits 10, at the domain cam.ac.uk.
</P> </P>
<br><a name="SEC5" href="#TOC1">REVISION</a><br> <br><a name="SEC5" href="#TOC1">REVISION</a><br>
<P> <P>
Last updated: 17 September 2018 Last updated: 28 April 2021
<br> <br>
Copyright &copy; 1997-2018 University of Cambridge. Copyright &copy; 1997-2021 University of Cambridge.
<br> <br>
<p> <p>
Return to the <a href="index.html">PCRE2 index page</a>. Return to the <a href="index.html">PCRE2 index page</a>.

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@ -1213,7 +1213,7 @@ Setting match controls
The following modifiers affect the matching process or request additional The following modifiers affect the matching process or request additional
information. Some of them may also be specified on a pattern line (see above), information. Some of them may also be specified on a pattern line (see above),
in which case they apply to every subject line that is matched against that in which case they apply to every subject line that is matched against that
pattern. pattern, but can be overridden by modifiers on the subject.
<pre> <pre>
aftertext show text after match aftertext show text after match
allaftertext show text after captures allaftertext show text after captures
@ -1421,6 +1421,11 @@ replacement strings cannot contain commas, because a comma signifies the end of
a modifier. This is not thought to be an issue in a test program. a modifier. This is not thought to be an issue in a test program.
</P> </P>
<P> <P>
Specifying a completely empty replacement string disables this modifier.
However, it is possible to specify an empty replacement by providing a buffer
length, as described below, for an otherwise empty replacement.
</P>
<P>
Unlike subject strings, <b>pcre2test</b> does not process replacement strings Unlike subject strings, <b>pcre2test</b> does not process replacement strings
for escape sequences. In UTF mode, a replacement string is checked to see if it for escape sequences. In UTF mode, a replacement string is checked to see if it
is a valid UTF-8 string. If so, it is correctly converted to a UTF string of is a valid UTF-8 string. If so, it is correctly converted to a UTF string of
@ -2119,9 +2124,9 @@ Cambridge, England.
</P> </P>
<br><a name="SEC21" href="#TOC1">REVISION</a><br> <br><a name="SEC21" href="#TOC1">REVISION</a><br>
<P> <P>
Last updated: 14 September 2020 Last updated: 28 April 2021
<br> <br>
Copyright &copy; 1997-2020 University of Cambridge. Copyright &copy; 1997-2021 University of Cambridge.
<br> <br>
<p> <p>
Return to the <a href="index.html">PCRE2 index page</a>. Return to the <a href="index.html">PCRE2 index page</a>.

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@ -34,16 +34,21 @@ INTRODUCTION
requesting some minor changes that give better ECMAScript (aka Java- requesting some minor changes that give better ECMAScript (aka Java-
Script) compatibility. Script) compatibility.
The source code for PCRE2 can be compiled to support 8-bit, 16-bit, or The source code for PCRE2 can be compiled to support strings of 8-bit,
32-bit code units, which means that up to three separate libraries may 16-bit, or 32-bit code units, which means that up to three separate li-
be installed. The original work to extend PCRE to 16-bit and 32-bit braries may be installed, one for each code unit size. The size of code
code units was done by Zoltan Herczeg and Christian Persch, respec- unit is not related to the bit size of the underlying hardware. In a
tively. In all three cases, strings can be interpreted either as one 64-bit environment that also supports 32-bit applications, versions of
character per code unit, or as UTF-encoded Unicode, with support for PCRE2 that are compiled in both 64-bit and 32-bit modes may be needed.
Unicode general category properties. Unicode support is optional at
build time (but is the default). However, processing strings as UTF The original work to extend PCRE to 16-bit and 32-bit code units was
code units must be enabled explicitly at run time. The version of Uni- done by Zoltan Herczeg and Christian Persch, respectively. In all three
code in use can be discovered by running cases, strings can be interpreted either as one character per code
unit, or as UTF-encoded Unicode, with support for Unicode general cate-
gory properties. Unicode support is optional at build time (but is the
default). However, processing strings as UTF code units must be enabled
explicitly at run time. The version of Unicode in use can be discovered
by running
pcre2test -C pcre2test -C
@ -177,8 +182,8 @@ AUTHOR
REVISION REVISION
Last updated: 17 September 2018 Last updated: 28 April 2021
Copyright (c) 1997-2018 University of Cambridge. Copyright (c) 1997-2021 University of Cambridge.
------------------------------------------------------------------------------ ------------------------------------------------------------------------------

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@ -1084,7 +1084,8 @@ SUBJECT MODIFIERS
The following modifiers affect the matching process or request addi- The following modifiers affect the matching process or request addi-
tional information. Some of them may also be specified on a pattern tional information. Some of them may also be specified on a pattern
line (see above), in which case they apply to every subject line that line (see above), in which case they apply to every subject line that
is matched against that pattern. is matched against that pattern, but can be overridden by modifiers on
the subject.
aftertext show text after match aftertext show text after match
allaftertext show text after captures allaftertext show text after captures
@ -1276,6 +1277,11 @@ SUBJECT MODIFIERS
end of a modifier. This is not thought to be an issue in a test pro- end of a modifier. This is not thought to be an issue in a test pro-
gram. gram.
Specifying a completely empty replacement string disables this modi-
fier. However, it is possible to specify an empty replacement by pro-
viding a buffer length, as described below, for an otherwise empty re-
placement.
Unlike subject strings, pcre2test does not process replacement strings Unlike subject strings, pcre2test does not process replacement strings
for escape sequences. In UTF mode, a replacement string is checked to for escape sequences. In UTF mode, a replacement string is checked to
see if it is a valid UTF-8 string. If so, it is correctly converted to see if it is a valid UTF-8 string. If so, it is correctly converted to
@ -1929,5 +1935,5 @@ AUTHOR
REVISION REVISION
Last updated: 14 September 2020 Last updated: 28 April 2021
Copyright (c) 1997-2020 University of Cambridge. Copyright (c) 1997-2021 University of Cambridge.