diff options
author | Peter Eisentraut | 2009-08-04 22:04:37 +0000 |
---|---|---|
committer | Peter Eisentraut | 2009-08-04 22:04:37 +0000 |
commit | c29d7f02c27c72b01c4fa90e24c4d33b5078a169 (patch) | |
tree | e535aca89fdc0513c3624f704f81b9130b3838f9 /doc/src | |
parent | b1732111f233bbb72788e92a627242ec28a85631 (diff) |
Use DocBook XSL stylesheets for man page building
This switches the man page building process to use the DocBook XSL stylesheet
toolchain. The previous targets for Docbook2X are removed. configure has been
updated to look for the new tools. The Documentation appendix contains the
new build instructions. There are also a few isolated tweaks in the
documentation to improve places that came out strangely in the man pages.
Diffstat (limited to 'doc/src')
-rw-r--r-- | doc/src/sgml/Makefile | 58 | ||||
-rw-r--r-- | doc/src/sgml/docguide.sgml | 92 | ||||
-rw-r--r-- | doc/src/sgml/postgres.sgml | 4 | ||||
-rw-r--r-- | doc/src/sgml/ref/analyze.sgml | 4 | ||||
-rw-r--r-- | doc/src/sgml/stylesheet-man.xsl | 160 | ||||
-rw-r--r-- | doc/src/sgml/trigger.sgml | 4 |
6 files changed, 211 insertions, 111 deletions
diff --git a/doc/src/sgml/Makefile b/doc/src/sgml/Makefile index 7e1e113f149..33bd247629e 100644 --- a/doc/src/sgml/Makefile +++ b/doc/src/sgml/Makefile @@ -2,7 +2,7 @@ # # PostgreSQL documentation makefile # -# $PostgreSQL: pgsql/doc/src/sgml/Makefile,v 1.119 2009/07/20 18:34:58 petere Exp $ +# $PostgreSQL: pgsql/doc/src/sgml/Makefile,v 1.120 2009/08/04 22:04:37 petere Exp $ # #---------------------------------------------------------------------------- @@ -33,17 +33,15 @@ ifndef NSGMLS NSGMLS = nsgmls endif -ifndef SGMLSPL -SGMLSPL = sgmlspl +ifndef OSX +OSX = osx endif -ifndef DOCBOOK2MAN -DOCBOOK2MAN = docbook2man_is_missing +ifndef XSLTPROC +XSLTPROC = xsltproc endif -# docbook2man generates man pages from docbook refentry source code. -D2MSCRIPT= $(D2MDIR)/docbook2man-spec.pl -D2MLINKS = $(D2MDIR)/docbook2man-spec_makelinks +override XSLTPROCFLAGS += --stringparam pg.version '$(VERSION)' GENERATED_SGML = bookindex.sgml version.sgml \ @@ -70,25 +68,14 @@ override SPFLAGS += -wall -wno-unused-param -wno-empty -wfully-tagged ## Man pages ## -.PHONY: html man draft clean +.PHONY: man -DEFAULTSECTION = l +man: man-stamp -fix_man_xrefs = $(PERL) -npi -e 's{\[XRef to GUC-([A-Z0-9-]*)\]}{($$l = $$1) =~ tr/A-Z-/a-z_/, $$l}ge || s{\[XRef to [A-Z0-9-]*\]}{in the documentation}g' -lowercase = tr 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' 'abcdefghijklmnopqrstuvwxyz' - -man: postgres.sgml $(ALLSGML) - $(NSGMLS) $(NSGMLS_FLAGS) $(SGMLINCLUDE) $< | $(SGMLSPL) $(D2MSCRIPT) --lowercase --section $(DEFAULTSECTION) --date "`date '+%Y-%m-%d'`" -# One more time, to resolve cross-references - $(NSGMLS) $(NSGMLS_FLAGS) $(SGMLINCLUDE) $< | $(SGMLSPL) $(D2MSCRIPT) --lowercase --section $(DEFAULTSECTION) --date "`date '+%Y-%m-%d'`" - $(fix_man_xrefs) *.1 *.7 - $(mkinstalldirs) man1 man7 - $(D2MLINKS) < manpage.links - mv *.1 man1/ - mv *.7 man7/ - rm *.$(DEFAULTSECTION) -# manpage.links doesn't handle lowercase, needs fixups - cd man7 && for file in `awk '{ print $$2 }' ../manpage.links`; do $(lowercase) <$$file >`echo $$file | $(lowercase)` && rm $$file || exit; done +man-stamp: stylesheet-man.xsl postgres.xml + $(XSLTPROC) $(XSLTPROCFLAGS) $^ + rm man1/SPI* man1/dblink* + touch $@ ## @@ -97,6 +84,8 @@ man: postgres.sgml $(ALLSGML) all: html +.PHONY: html draft + JADE.html.call = $(JADE) $(JADEFLAGS) $(SPFLAGS) $(SGMLINCLUDE) $(CATALOG) -d stylesheet.dsl -t sgml -i output-html # The draft target creates HTML output in draft mode, without index (for faster build). @@ -222,9 +211,6 @@ regress_README.html: regress.sgml ## XSLT processing ## -OSX = osx # (may be called sx or sgml2xml on some systems) -XSLTPROC = xsltproc - postgres.xml: postgres.sgml $(ALMOSTALLSGML) $(OSX) -D. -x lower $< | \ $(PERL) -p -e 's/\[(amp|copy|egrave|gt|lt|mdash|nbsp|ouml|pi|quot|uuml) *\]/\&\1;/g;' \ @@ -232,8 +218,6 @@ postgres.xml: postgres.sgml $(ALMOSTALLSGML) >$@ # ' hello Emacs -override XSLTPROCFLAGS += --stringparam pg.version '$(VERSION)' - xslthtml: stylesheet.xsl postgres.xml $(XSLTPROC) $(XSLTPROCFLAGS) $^ @@ -269,18 +253,6 @@ MAKEINFO = makeinfo ## -## Experimental man page building through docbook2x -## - -manx: postgres.xml stylesheet-man.xsl - $(DOCBOOK2MAN) --solinks -s $(srcdir)/stylesheet-man.xsl --string-param default-manpage-section=$(DEFAULTSECTION) $< - $(mkinstalldirs) man1 man7 - mv *.1 man1/ - mv *.7 man7/ - rm *.$(DEFAULTSECTION) - - -## ## Check ## @@ -297,7 +269,7 @@ clean distclean maintainer-clean: # HTML rm -f *.html html-stamp # man - rm -rf *.1 *.7 *.$(DEFAULTSECTION) man1 man7 manpage.refs manpage.links manpage.log + rm -rf man1 man7 man-stamp # print rm -f *.rtf *.tex-ps *.tex-pdf *.dvi *.aux *.log *.ps *.pdf *.out *.fot # index diff --git a/doc/src/sgml/docguide.sgml b/doc/src/sgml/docguide.sgml index 4aafc4e2a02..9e07f5a31a6 100644 --- a/doc/src/sgml/docguide.sgml +++ b/doc/src/sgml/docguide.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/docguide.sgml,v 1.76 2009/06/17 21:58:49 tgl Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/docguide.sgml,v 1.77 2009/08/04 22:04:37 petere Exp $ --> <appendix id="docguide"> <title>Documentation</title> @@ -83,13 +83,14 @@ <variablelist> <varlistentry> - <term><ulink url="http://www.oasis-open.org/docbook/sgml/">DocBook DTD</ulink></term> + <term><ulink url="http://www.oasis-open.org/docbook/">DocBook DTD</ulink></term> <listitem> <para> This is the definition of DocBook itself. We currently use - version 4.2; you cannot use later or earlier versions. Note - that there is also an <acronym>XML</acronym> version of DocBook - — do not use that. + version 4.2; you cannot use later or earlier versions. You + need the <acronym>SGML</acronym> variant of the DocBook DTD, + but to build man pages you also need the <acronym>XML</acronym> + variant of the same version. </para> </listitem> </varlistentry> @@ -105,47 +106,51 @@ </varlistentry> <varlistentry> - <term><ulink url="http://openjade.sourceforge.net">OpenJade</ulink></term> + <term><ulink url="http://wiki.docbook.org/topic/DocBookDssslStylesheets">DocBook DSSSL Stylesheets</ulink></term> <listitem> <para> - This is the base package of <acronym>SGML</acronym> processing. - It contains an <acronym>SGML</acronym> parser, a - <acronym>DSSSL</acronym> processor (that is, a program to - convert <acronym>SGML</acronym> to other formats using - <acronym>DSSSL</acronym> stylesheets), as well as a number of - related tools. <productname>Jade</productname> is now being - maintained by the OpenJade group, no longer by James Clark. + These contain the processing instructions for converting the + DocBook sources to other formats, such as + <acronym>HTML</acronym>. </para> </listitem> </varlistentry> <varlistentry> - <term><ulink url="http://wiki.docbook.org/topic/DocBookDssslStylesheets">DocBook DSSSL Stylesheets</ulink></term> + <term><ulink url="http://wiki.docbook.org/topic/DocBookXslStylesheets">DocBook XSL Stylesheets</ulink></term> <listitem> <para> - These contain the processing instructions for converting the - DocBook sources to other formats, such as - <acronym>HTML</acronym>. + This is another stylesheet for converting DocBook to other + formats. We currently use this to produce man pages and + optionally HTMLHelp. You can also use this toolchain to + produce HTML or PDF output, but official PostgreSQL releases + use the DSSSL stylesheets for that. </para> </listitem> </varlistentry> <varlistentry> - <term><ulink url="http://search.cpan.org/dist/SGMLSpm/">SGMLSpm</ulink></term> + <term><ulink url="http://openjade.sourceforge.net">OpenJade</ulink></term> <listitem> <para> - This optional package is used to create man pages. + This is the base package of <acronym>SGML</acronym> processing. + It contains an <acronym>SGML</acronym> parser, a + <acronym>DSSSL</acronym> processor (that is, a program to + convert <acronym>SGML</acronym> to other formats using + <acronym>DSSSL</acronym> stylesheets), as well as a number of + related tools. <productname>Jade</productname> is now being + maintained by the OpenJade group, no longer by James Clark. </para> </listitem> </varlistentry> <varlistentry> - <term><ulink url="http://docbook2x.sourceforge.net">DocBook2X</ulink></term> + <term><ulink url="http://xmlsoft.org/XSLT/">Libxslt</ulink> for <command>xsltproc</command></term> <listitem> <para> - This optional package is also used to create man pages. You - want the <literal>docbook2man-sgmlspl</literal> package, not - the main <literal>docbook2x</literal> package. + This is the processing tool to use with the XSLT stylesheets + (like <command>jade</command> is the processing tool for DSSSL + stylesheets). </para> </listitem> </varlistentry> @@ -263,13 +268,8 @@ CATALOG "docbook/4.2/catalog" available for <productname>Debian GNU/Linux</productname>. To install, simply use: <programlisting> -apt-get install openjade1.3 -apt-get install docbook -apt-get install docbook-dsssl -apt-get install sgmlspl # for the man pages +apt-get install docbook docbook-dsssl docbook-xsl openjade xsltproc </programlisting> - (The plain <literal>openjade</literal> package installs - OpenJade 1.4, which seems not to work.) </para> </sect2> @@ -511,13 +511,15 @@ CATALOG "docbook-dsssl-1.<replaceable>xx</>/catalog" checking for onsgmls... onsgmls checking for openjade... openjade checking for DocBook V4.2... yes -checking for DocBook stylesheets... /usr/lib/sgml/stylesheets/nwalsh-modular -checking for sgmlspl... sgmlspl +checking for DocBook stylesheets... /usr/share/sgml/docbook/stylesheet/dsssl/modular +checking for collateindex.pl... /usr/bin/collateindex.pl +checking for xsltproc... xsltproc +checking for osx... osx </computeroutput> </screen> If neither <filename>onsgmls</filename> nor - <filename>nsgmls</filename> were found then you will not see the - remaining 4 lines. <filename>nsgmls</filename> is part of the Jade + <filename>nsgmls</filename> were found then some of the following tests + will be skipped. <filename>nsgmls</filename> is part of the Jade package. You can pass the environment variables <envar>JADE</envar> and <envar>NSGMLS</envar> to configure to point to the programs if they are not found automatically. If @@ -583,8 +585,7 @@ gmake postgres.tar.gz <title>Manpages</title> <para> - We use the <application>docbook2man-sgmlspl</application> utility - from the <productname>DocBook2X</productname> project to + We use the DocBook XSL stylesheets to convert <productname>DocBook</productname> <sgmltag>refentry</sgmltag> pages to *roff output suitable for man pages. The man pages are also distributed as a tar archive, @@ -592,32 +593,15 @@ gmake postgres.tar.gz pages, use the commands: <programlisting> cd doc/src/sgml -gmake man D2MDIR=<replaceable>directory</replaceable> +gmake man </programlisting> - Use the <varname>D2MDIR</varname> variable to specify the name of - the directory where the - file <filename>docbook2man-spec.pl</filename> from - the <application>docbook2man-sgmlspl</application> package resides. - There is no default for that. Since that package is not available - or outdated in many packaging systems, you might want to just - download the source code tarball and unpack it. No building is - required. Then the path is something - like <literal>D2MDIR=/home/you/somewhere/docbook2man-sgmlspl-1.0/perl</literal>. - You may get warnings like this: -<screen> -Warning: unrecognized SDATA '[scaron]': please add definition to docbook2man-spec.pl -Warning: unrecognized SDATA '[ouml ]': please add definition to docbook2man-spec.pl -</screen> - which can ignore if (and only if) you are using the latest version - of <filename>docbook2man-spec.pl</filename> - and you are not seeing any other SDATA warnings besides those. </para> <para> To create the man page package for a release, use the following commands: <programlisting> cd doc/src -gmake man.tar.gz D2MDIR=<replaceable>directory</replaceable> +gmake man.tar.gz </programlisting> which will result in a tar file being generated in the <filename>doc/src</filename> directory. diff --git a/doc/src/sgml/postgres.sgml b/doc/src/sgml/postgres.sgml index d4c4d40bbe2..caebed54447 100644 --- a/doc/src/sgml/postgres.sgml +++ b/doc/src/sgml/postgres.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/postgres.sgml,v 1.89 2009/07/14 22:16:38 petere Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/postgres.sgml,v 1.90 2009/08/04 22:04:37 petere Exp $ --> <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook V4.2//EN" [ @@ -16,6 +16,8 @@ <bookinfo> <corpauthor>The PostgreSQL Global Development Group</corpauthor> + <productname>PostgreSQL</productname> + <productnumber>&version;</productnumber> &legal; </bookinfo> diff --git a/doc/src/sgml/ref/analyze.sgml b/doc/src/sgml/ref/analyze.sgml index c0d2673dc50..cb9f20f3f56 100644 --- a/doc/src/sgml/ref/analyze.sgml +++ b/doc/src/sgml/ref/analyze.sgml @@ -1,5 +1,5 @@ <!-- -$PostgreSQL: pgsql/doc/src/sgml/ref/analyze.sgml,v 1.26 2009/08/02 22:14:51 tgl Exp $ +$PostgreSQL: pgsql/doc/src/sgml/ref/analyze.sgml,v 1.27 2009/08/04 22:04:37 petere Exp $ PostgreSQL documentation --> @@ -94,7 +94,7 @@ ANALYZE [ VERBOSE ] [ <replaceable class="PARAMETER">table</replaceable> [ ( <re <para> In the default <productname>PostgreSQL</productname> configuration, - <xref linkend="autovacuum" endterm="autovacuum-title"> + the autovacuum daemon (see <xref linkend="autovacuum">) takes care of automatic analyzing of tables when they are first loaded with data, and as they change throughout regular operation. When autovacuum is disabled, diff --git a/doc/src/sgml/stylesheet-man.xsl b/doc/src/sgml/stylesheet-man.xsl index 2d37a42f1a5..842a9bd5039 100644 --- a/doc/src/sgml/stylesheet-man.xsl +++ b/doc/src/sgml/stylesheet-man.xsl @@ -1,16 +1,158 @@ -<?xml version="1.0" encoding="utf-8"?> +<?xml version='1.0'?> <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" - version="1.0"> + xmlns:exsl="http://exslt.org/common" + version='1.0' + exclude-result-prefixes="exsl"> -<xsl:import href="http://docbook2x.sourceforge.net/latest/xslt/man/docbook.xsl"/> +<xsl:import href="http://docbook.sourceforge.net/release/xsl/current/manpages/docbook.xsl"/> +<xsl:import href="stylesheet-common.xsl" /> -<!-- - Man pages don't really support a third section level, but this - makes our man pages work OK and matches the behavior of the sgmlspl - style. + +<!-- The following is a workaround for what may actually be a mistake + in our markup. The problem is in a situation like + +<para> + <command>FOO</command> is ... + + there is strictly speaking a line break before "FOO". In the + HTML output, this does not appear to be a problem, but in the man + page output, this shows up. Using this setting, pure whitespace + text nodes are removed, so the problem is solved. --> +<xsl:strip-space elements="para"/> + + +<!-- Parameters --> + +<xsl:param name="man.authors.section.enabled">0</xsl:param> +<xsl:param name="man.copyright.section.enabled">0</xsl:param> +<xsl:param name="man.output.base.dir"></xsl:param> +<xsl:param name="man.output.in.separate.dir" select="1"></xsl:param> +<xsl:param name="refentry.meta.get.quietly" select="0"></xsl:param> +<xsl:param name="man.th.extra3.max.length">40</xsl:param> <!-- enough room for "PostgreSQL 8.5devel Documentation" --> +<xsl:param name="refentry.xref.manvolnum" select="1"/> <!-- overridden from stylesheet-common.xsl --> + +<!-- Fixup for apostrophe groff output. See the following references: + <http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=457839> + <https://sourceforge.net/tracker/?func=detail&aid=2412738&group_id=21935&atid=373747> --> -<xsl:template match="refsect3"> - <xsl:call-template name="SS-section" /> +<xsl:param name="man.string.subst.map.local.post"> + <substitution oldstring="\'" newstring="\(aq"></substitution> +</xsl:param> + + +<!-- Custom templates --> + +<xsl:template match="refentry" mode="xref-to"> + <xsl:param name="referrer"/> + <xsl:param name="xrefstyle"/> + + <xsl:choose> + <!-- If the refname contains a space, we construct a reference + like CREATE DATABASE (CREATE_DATABASE(7)), so the reader + knows both the command name being referred to and the name of + the man page to read about it. --> + <xsl:when test="contains(refnamediv/refname[1],' ')"> + <xsl:variable name="mangled.title"> + <xsl:value-of select="translate(refnamediv/refname[1],' ','_')"/> + </xsl:variable> + <xsl:apply-templates select="refnamediv/refname[1]"/> + <xsl:text> (</xsl:text> + <xsl:call-template name="bold"> + <xsl:with-param name="node" select="exsl:node-set($mangled.title)"/> + <xsl:with-param name="context" select="."/> + </xsl:call-template> + <xsl:apply-templates select="refmeta/manvolnum"/> + <xsl:text>)</xsl:text> + </xsl:when> + + <!-- This is the original case, except that boldness has been + added, per the convention mentioned in man-pages(7). --> + <xsl:otherwise> + <xsl:choose> + <xsl:when test="refmeta/refentrytitle"> + <xsl:call-template name="bold"> + <xsl:with-param name="node" select="refmeta/refentrytitle"/> + <xsl:with-param name="context" select="."/> + </xsl:call-template> + </xsl:when> + <xsl:otherwise> + <xsl:call-template name="bold"> + <xsl:with-param name="node" select="refnamediv/refname[1]"/> + <xsl:with-param name="context" select="."/> + </xsl:call-template> + </xsl:otherwise> + </xsl:choose> + <xsl:apply-templates select="refmeta/manvolnum"/> + </xsl:otherwise> + </xsl:choose> + </xsl:template> + +<!-- Overridden template as workaround for this problem: + <https://sourceforge.net/tracker/?func=detail&aid=2831602&group_id=21935&atid=373747> +--> + <xsl:template name="write.stubs"> + <xsl:param name="first.refname"/> + <xsl:param name="section"/> + <xsl:param name="lang"/> + <xsl:for-each select="refnamediv/refname"> + <xsl:if test=". != $first.refname"> + <xsl:call-template name="write.text.chunk"> + <xsl:with-param name="filename"> + <xsl:call-template name="make.adjusted.man.filename"> + <xsl:with-param name="name" select="."/> + <xsl:with-param name="section" select="$section"/> + <xsl:with-param name="lang" select="$lang"/> + </xsl:call-template> + </xsl:with-param> + <xsl:with-param name="quiet" select="$man.output.quietly"/> + <xsl:with-param name="suppress-context-node-name" select="1"/> + <xsl:with-param name="message-prolog">Note: </xsl:with-param> + <xsl:with-param name="message-epilog"> (soelim stub)</xsl:with-param> + <xsl:with-param name="content"> + <xsl:choose> + <xsl:when test="$man.output.in.separate.dir = 0"> + <xsl:value-of select="concat('.so man', $section, '/')"/> + </xsl:when> + <xsl:otherwise> + <xsl:value-of select="'.so '"/> <!-- added case --> + </xsl:otherwise> + </xsl:choose> + <xsl:call-template name="make.adjusted.man.filename"> + <xsl:with-param name="name" select="$first.refname"/> + <xsl:with-param name="section" select="$section"/> + </xsl:call-template> + <xsl:text> </xsl:text> + </xsl:with-param> + </xsl:call-template> + </xsl:if> + </xsl:for-each> + </xsl:template> + + +<!-- Gentext customization --> + +<!-- see http://www.sagehill.net/docbookxsl/CustomGentext.html --> +<xsl:param name="local.l10n.xml" select="document('')"/> +<l:i18n xmlns:l="http://docbook.sourceforge.net/xmlns/l10n/1.0"> + <l:l10n language="en"> + <!-- Use ISO 8601 date format. --> + <l:context name="datetime"> + <l:template name="format" text="Y-m-d"/> + </l:context> + + <!-- Slight rephrasing to indicate that missing sections are found + in the documentation. --> + <l:context name="xref-number-and-title"> + <l:template name="chapter" text="Chapter %n, %t, in the documentation"/> + <l:template name="sect1" text="Section %n, “%t”, in the documentation"/> + <l:template name="sect2" text="Section %n, “%t”, in the documentation"/> + <l:template name="sect3" text="Section %n, “%t”, in the documentation"/> + <l:template name="sect4" text="Section %n, “%t”, in the documentation"/> + <l:template name="sect5" text="Section %n, “%t”, in the documentation"/> + </l:context> + </l:l10n> +</l:i18n> + </xsl:stylesheet> diff --git a/doc/src/sgml/trigger.sgml b/doc/src/sgml/trigger.sgml index 348434f9174..50e5943401b 100644 --- a/doc/src/sgml/trigger.sgml +++ b/doc/src/sgml/trigger.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/trigger.sgml,v 1.57 2009/07/28 02:56:29 tgl Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/trigger.sgml,v 1.58 2009/08/04 22:04:37 petere Exp $ --> <chapter id="triggers"> <title>Triggers</title> @@ -541,7 +541,7 @@ typedef struct Trigger </sect1> <sect1 id="trigger-example"> - <title>A Complete Example</title> + <title>A Complete Trigger Example</title> <para> Here is a very simple example of a trigger function written in C. |