--- loncom/build/lpml_parse.pl 2002/04/08 12:51:03 1.44 +++ loncom/build/lpml_parse.pl 2002/04/13 19:29:32 1.45 @@ -4,11 +4,15 @@ # Run "perldoc ./lpml_parse.pl" in order to best view the software # documentation internalized in this program. +# --------------------------------------------------------- Distribution notice +# This script is distributed with the LPML software project available at +# http://lpml.sourceforge.net + # --------------------------------------------------------- License Information # The LearningOnline Network with CAPA # lpml_parse.pl - Linux Packaging Markup Language parser # -# $Id: lpml_parse.pl,v 1.44 2002/04/08 12:51:03 harris41 Exp $ +# $Id: lpml_parse.pl,v 1.45 2002/04/13 19:29:32 harris41 Exp $ # # Written by Scott Harrison, codeharrison@yahoo.com # @@ -42,7 +46,7 @@ # 11/4,11/5,11/6,11/7,11/16,11/17 - Scott Harrison # 12/2,12/3,12/4,12/5,12/6,12/13,12/19,12/29 - Scott Harrison # YEAR=2002 -# 1/8,1/9,1/29,1/31,2/5,3/21,4/8 - Scott Harrison +# 1/8,1/9,1/29,1/31,2/5,3/21,4/8,4/12 - Scott Harrison # ### @@ -63,8 +67,7 @@ # # I am using a multiple pass-through approach to parsing # the lpml file. This saves memory and makes sure the server -# will never be overloaded. At some point, I expect the -# first two steps will be implemented with my XFML +# will never be overloaded. # # This is meant to parse files meeting the lpml document type. # See lpml.dtd. LPML=Linux Packaging Markup Language. @@ -74,9 +77,12 @@ use HTML::TokeParser; my $usage=<; -my $parsestring = join('',@parsecontents); -my $outstring=''; +# -------------------------- Start first pass through (just gather information) +my @parsecontents=<>; +my $parsestring=join('',@parsecontents); # Need to make a pass through and figure out what defaults are -# overrided. Top-down overriding strategy (leaves don't know -# about distant leaves). +# overrided. Top-down overriding strategy (tree leaves don't know +# about distant tree leaves). my @hierarchy; $hierarchy[0]=0; @@ -157,20 +164,32 @@ my $token; $parser = HTML::TokeParser->new(\$parsestring) or die('can\'t create TokeParser object'); $parser->xml_mode('1'); -my %hash; -my $key=''; -while ($token = $parser->get_token()) { +my %setting; + +# Values for the %setting hash +my $defaultset=1; # a default setting exists for a key +my $distset=2; # a distribution setting exists for a key + # (overrides default setting) + +my $key=''; # this is a unique key identifier (the token name with its + # coordinates inside the hierarchy) +while ($token = $parser->get_token()) { # navigate through $parsestring if ($token->[0] eq 'S') { $hloc++; $hierarchy[$hloc]++; $key=$token->[1].join(',',@hierarchy[0..($hloc-1)]); my $thisdist=' '.$token->[2]{'dist'}.' '; if ($thisdist eq ' default ') { - $hash{$key}=1; # there is a default setting for this key + $setting{$key}=$defaultset; } - elsif ($dist && $hash{$key}==1 && $thisdist=~/\s$dist\s/) { - $hash{$key}=2; # disregard default setting for this key if - # there is a directly requested distribution match + elsif (length($dist)>0 && + $setting{$key}==$defaultset && + $thisdist=~/\s$dist\s/) { + $setting{$key}=$distset; + # disregard default setting for this key if + # there is a directly requested distribution match + # (in other words, there must first be a default + # setting for a key in order for it to be overridden) } } if ($token->[0] eq 'E') { @@ -178,57 +197,79 @@ while ($token = $parser->get_token()) { } } -# --------------------------------------------------- Start second pass through +# - Start second pass through (clean up the string to allow for easy rendering) + +# The string is cleaned up so that there is no white-space surrounding any +# XML tag. White-space inside text 'T' elements is preserved. + +# Clear up memory undef($hloc); undef(@hierarchy); undef($parser); -$hierarchy[0]=0; +$hierarchy[0]=0; # initialize hierarchy $parser = HTML::TokeParser->new(\$parsestring) or die('can\'t create TokeParser object'); $parser->xml_mode('1'); -my $cleanstring; -while ($token = $parser->get_token()) { - if ($token->[0] eq 'S') { +my $cleanstring; # contains the output of the second step +while ($token = $parser->get_token()) { # navigate through $parsestring + if ($token->[0] eq 'S') { # a start tag $hloc++; $hierarchy[$hloc]++; $key=$token->[1].join(',',@hierarchy[0..($hloc-1)]); - my $thisdist=' '.$token->[2]{'dist'}.' '; + + # Surround tagdist (the dist attribute of an XML tag) + # with white-space to allow for uniform searching a few + # lines below here. + my $tagdist=' '.$token->[2]{'dist'}.' '; + # This conditional clause is set up to ignore two sets # of invalid conditions before accepting entry into - # the cleanstring. - if ($hash{$key}==2 and - !($thisdist eq ' ' or $thisdist =~/\s$dist\s/)) { + # $cleanstring. + + # Condition #1: Ignore this part of the string if the tag + # has a superior distribution-specific setting and the tag + # being evaluated has a dist setting something other than + # blank or $dist. + if ($setting{$key}==$distset and + !($tagdist eq ' ' or $tagdist =~/\s$dist\s/)) { if ($token->[4]!~/\/>$/) { $parser->get_tag('/'.$token->[1]); $hloc--; } } - elsif ($thisdist ne ' ' and $thisdist!~/\s$dist\s/ and - !($thisdist eq ' default ' and $hash{$key}!=2)) { + # Condition #2: Ignore this part of the string if the tag has + # is not blank and does not equal dist and + # either does not equal default or it has a prior $dist-specific + # setting. + elsif ($tagdist ne ' ' and $tagdist!~/\s$dist\s/ and + !($tagdist eq ' default ' and $setting{$key}!=$distset)) { if ($token->[4]!~/\/>$/) { $parser->get_tag('/'.$token->[1]); $hloc--; } } + # In other words, output to $cleanstring if the tag is dist=default + # or if the tag is set to dist=$dist for the first time. And, always + # output when dist='' is not present. else { $cleanstring.=$token->[4]; } - if ($token->[4]=~/\/>$/) { -# $hloc--; - } } - if ($token->[0] eq 'E') { + # Note: this loop DOES work with style markup as well as + # style markup since I always check for $token->[4] ending + # with "/>". + if ($token->[0] eq 'E') { # an end tag $cleanstring.=$token->[2]; $hloc--; } - if ($token->[0] eq 'T') { + if ($token->[0] eq 'T') { # text contents inside tags $cleanstring.=$token->[1]; } } $cleanstring=&trim($cleanstring); $cleanstring=~s/\>\s*\n\s*\\ | perl lpml_parse.pl + +Usage is for the lpml file to come in through standard input. =over 4 @@ -1595,19 +1638,57 @@ Only the 1st argument is mandatory for t Example: cat ../../doc/loncapafiles.lpml |\\ -perl lpml_parse.pl html default /home/sherbert/loncapa /tmp/install +perl lpml_parse.pl html runtime default /home/sherbert/loncapa /tmp/install =head1 DESCRIPTION -I am using a multiple pass-through approach to parsing -the lpml file. This saves memory and makes sure the server -will never be overloaded. +The general flow of the script is to get command line arguments, run through +the XML document three times, and output according to any desired mode: +install, configinstall, build, rpm, dpkg, htmldoc, textdoc, and status. + +A number of coding decisions are made according to the following principle: +installation software must be stand-alone. Therefore, for instance, I try +not to use the GetOpt::Long module or any other perl modules. (I do however +use HTML::TokeParser.) I also have tried to keep all the MODES of +parsing inside this file. Therefore, format_TAG subroutines are fairly +lengthy with their conditional logic. A more "elegant" solution might +be to dynamically register the parsing mode and subroutines, or maybe even work +with stylesheets. However, in order to make this the installation back-bone +of choice, there are advantages for HAVING EVERYTHING IN ONE FILE. +This way, the LPML installation software does not have to rely on OTHER +installation software (a chicken versus the egg problem). Besides, I would +suggest the modes of parsing are fairly constant: install, configinstall, +build, rpm, dpkg, htmldoc, textdoc, and status. + +Another coding decision is about using a multiple pass-through approach to +parsing the lpml file. This saves memory and makes sure the server will never +be overloaded. During the first pass-through, the script gathers information +specific as to resolving what tags with what 'dist=' attributes are to be used. +During the second pass-through, the script cleans up white-space surrounding +the XML tags, and filters through the tags based on information regarding the +'dist=' attributes (information gathered in the first pass-through). +The third and final pass-through involves formatting and rendering the XML +into whatever XML mode is chosen: install, configinstall, build, rpm, dpkg, +htmldoc, textdoc, and status. + +The hierarchy mandated by the DTD does not always correspond to the hierarchy +that is sensible for a Makefile. For instance, in a Makefile it is sensible +that soft-links are installed after files. However, in an LPML document, it +is sensible that files and links be considered together and the writer of the +LPML document should be free to place things in whatever order makes best +sense in terms of LOOKING at the information. The complication that arises +is that the parser needs to have a memory for passing values from +leaves on the XML tree to higher-up branches. Currently, this memory is +hard-coded (like with the @links array), but it may benefit from a more +formal approach in the future. =head1 README -I am using a multiple pass-through approach to parsing -the lpml file. This saves memory and makes sure the server -will never be overloaded. +This parses an LPML file to generate information useful for +source to target installation, compilation, filesystem status +checking, RPM and Debian software packaging, and documentation. + +More information on LPML is available at http://lpml.sourceforge.net. =head1 PREREQUISITES @@ -1621,7 +1702,7 @@ linux =head1 SCRIPT CATEGORIES -Packaging/Administrative +UNIX/System_administration =head1 AUTHOR