#!/usr/bin/perl
#  Copyright (C) 2000-2001  Knut Haugen <knut.haugen@linpro.no>
#
#  This program is free software; you can redistribute it and/or
#  modify it under the terms of the GNU General Public License
#  as published by the Free Software Foundation; either version 2
#  of the License, or (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program; if not, write to the Free Software
#  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
#
# version 0.7

#Description:
# update or read a jar's manifest file in a simple manner 

use strict;
use Getopt::Std;

# the known keys
my ($TITLE)   = 'Implementation-Title';
my ($VENDOR)  = 'Implementation-Vendor';
my ($VERSION) = 'Implementation-Version';
my ($NAME)    = 'Name';

# the files we use
my ($MF_NAME) = 'META-INF/MANIFEST.MF';
my ($MF) = 'META-INF';
my ($MF_TMP) = 'manifest.txt';


#----------------------------------------
#main script                            #
#----------------------------------------

# the jar executable
my ($jar) = `which jar 2> /dev/null`;
if (checkExit()){
    chop ($jar);
}
else{
    print ("Couldn't find the jar executable.\n");
    printUsage (-1);
}

my ($only) = 0;

if ($#ARGV == 0 ){
	$only = 1;
}

my (%opts, $jarfile, %mf, @file);
getopts ("t:v:s:n:ph", \%opts) || printUsage (1);
if ( $opts{'h'}){
    printUsage(0);
}

if ( $#ARGV == 0){
    $jarfile = $ARGV[0];
    getManifest ();
    updateManifest();
}
else{
    print ("No jar file supplied.\n");
    printUsage (-1);
}


#print usage information
sub printUsage ( ){
    my ($exit) = shift;
	my $usage = <<EOF;
Usage $0 [OPTIONS] JARFILE
 -t <title> Set information for the Implementation-Title entry
 -v <vendor> Set information for the Implementation-Vendor entry
 -s <Version> Set information for the Implementation-Version entry
 -n <name> Set information for the Name entry
 -p flag to specifically tell the script to just print existing values.
     Also default if no option is given.
 -h  Print this help and exit.
EOF
	print ($usage);
	exit ($exit);

}

#update the manifest in the jar with the new information
sub updateManifest {
	# update all entries if given on the cmdline
	if (exists($opts{'t'})){
		$mf{$TITLE} = $opts{'t'};
	}
	if (exists($opts{'v'})){
		$mf{$VENDOR} = $opts{'v'};
	}
	if (exists($opts{'s'})){
		$mf{$VERSION} = $opts{'s'};
	}
	if (exists($opts{'n'})){
		$mf{$NAME} = $opts{'n'};
	}

	open (JAR, "> $MF_TMP") or die ("Could not open tmp manifest-file for writing\n");;
	print (JAR "$NAME: $mf{$NAME}\n");
	print (JAR "$TITLE: $mf{$TITLE}\n");
	if ($mf{$VENDOR} =~ /\"/){
		print (JAR "$VENDOR: $mf{$VENDOR}\n");
	}
	else{
		print (JAR "$VENDOR: \"$mf{$VENDOR}\"\n");
	}
	print (JAR "$VERSION: $mf{$VERSION}\n\n");
	print (JAR @file);
	close (JAR);
	makeNewjar ();
}


#update the jar with the new Manifest information
sub makeNewjar (){
	`$jar -ufm $jarfile $MF_TMP`;
	die ("Jar $jar not working properly. Is it in the path?") unless checkExit ();
	unlink ($MF_TMP);
	unlink ($MF_NAME);
	rmdir ($MF);
}

# get the manifest-file, well, really get the manifest
sub getManifest{
	if (-f $MF_NAME ){
		unlink ($MF_NAME); 
	}
    
    if (-f $jarfile) {
        `$jar -xf $jarfile $MF_NAME`;
        die ("Jar $jar not working properly. Is it in the path?") unless checkExit ();
        open (JAR, $MF_NAME) or die ("Could not open manifest file");
        my (@lines) = <JAR>;
        close (JAR);
        parseManifest ( @lines );
        if ($opts{'p'} || $only){
            unlink ($MF_NAME);
            rmdir ($MF);
            exit (0);
        }
    }
}

#check the exit status of the last process. Returns true for 
#exit 0 and false for all others.
sub checkExit (){
	return ($?>>8) == 0;
}

#Parse the manifest file and assign the values to the hash.
sub parseManifest {
	my ($test, $test2) = (0, 0);
	foreach (@_){
		$test=0;
		if (!/^\s/){
			my ($key, $value) = split (/:/, $_);
			$value  = substr($value, 1);
			if ($opts{'p'} || $only){
				print ("$key: $value");
			}
            if ($key =~ /Vendor/ || $key =~ /Version/ || $key =~ /Title/){
                chop ($value);
				$test=1;
            }
			if ($key =~ /Name/ && !$test2){
				chop ($value);
				$test=1;
				$test2=1;
			}
			if ($test){
				$mf{$key} = $value;			
			}
			elsif (!/^Created-By.*/){
				push (@file, $_);
			}
		}
		else{
			push (@file, $_);
		}
	} 
}


#pod people
__END__


=head1 Name

mf.pl - read and edit a jar's manifest file

=head1 Description

This script gives you easy access to the meta information in a jar file.
No need to unpack any files and cat them. The script does this under the
hood and prints the information. It also lets you set some of the 
values in the jar file.

=head1 Usage

mf.pl [OPTIONS] JARFILE 

=head1 Options

-h
    Print usage information and exit.

-t 
    Set the title in the manifest

-v 
    Set the vendor information in the manifest

-s 
    Set the version information in the manifest

-n 
    Set the name information in the manifest

-p 
    Only print the information in the manifest. This is the default
    behaviour if no option is given as well.

=head1 Author

Written by Knut Haugen, Linpro AS, <URL: http://www.linpro.no/>.
Copyright 2000-2001, Knut Haugen. Email: <knut.haugen@linpro.no>.

=cut