#!/bin/bash
#
# Blueprint to build gzip-1.2.4a.
#
# gzip is used for compression and decompression of files.
#
# Source code can be downloaded from http://www.gzip.org.
#
# This architect blueprint is copyright (c)2003-2004 David Horton
# dhorton@nospam.speakeasy.net
# 
# 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: 
#
#   Free Software Foundation, Inc.
#   59 Temple Place - Suite 330
#   Boston, MA 02111-1307, USA
#
#
# Define the package name, source directory, build directory and
# staging directory paths.  Prefixes to directories may be overridden
# by setting shell variables SRC, BUILD and STAGING.  For example,
# doing "export SRC=/root/foo" before calling this script will override
# the default /usr/src and set SRC_DIR to /root/foo/$PKG_NAME instead.
# 
PKG_NAME=$(basename $0)
SRC_DIR=${SRC:-/usr/src}/$PKG_NAME
BUILD_DIR=${BUILD:-/var/tmp/build}/$PKG_NAME
STAGING_DIR=${STAGING:-/var/tmp/staging}/$PKG_NAME
#
# Check that the source directory really exits and bail out if not.
if ! [ -d $SRC_DIR ]; then
  echo "$PKG_NAME: Cannot find source code directory $SRC_DIR."
  exit 1
fi
#
# Do not overwrite existing build directory.
if [ -d $BUILD_DIR ]; then
  echo "$PKG_NAME: Build directory $BUILD_DIR already exists."
  exit 2
else
  mkdir -p $BUILD_DIR
fi
#
# Do not overwrite existing staging directory.
if [ -d $STAGING_DIR ]; then
  echo "$PKG_NAME: Staging directory $STAGING_DIR already exists."
  exit 4
else
  mkdir -p $STAGING_DIR
fi
#
# Configure the package for FHS compliance and i386 processor.
export CC="gcc -mcpu=i386"
cd $BUILD_DIR
$SRC_DIR/configure \
  --host=i386-pc-linux-gnu \
  --prefix=/usr
#
# Check return status and bail out if it's non-zero.
if [ $? -gt 0 ]; then
  echo "$PKG_NAME: Configuration failed!"
  exit 8
fi
# Build the package.  
make
#
# Check return code and bail if it looks bad.
if [ $? -gt 0 ]; then
  echo "$PKG_NAME: Build failed!"
  exit 16
fi
#
# Install into staging area overriding make variables as needed.
mkdir $STAGING_DIR/usr
make \
  prefix=$STAGING_DIR/usr \
  install
#
# Check return code and bail if it looks bad.
if [ $? -gt 0 ]; then
  echo "$PKG_NAME: Installation to staging area failed!"
  exit 32
fi
#
# Do some post-install tweaking
#
# Move gzip into the /bin directory so that it can be used in recovery
# situations when the /usr hierarchy may not be mounted.
mkdir $STAGING_DIR/bin
mv $STAGING_DIR/usr/bin/gzip $STAGING_DIR/bin
#
# gunzip and zcat are just links to gzip and not really separate files.
# Since gzip was moved, gunzip and zcat will need to move too.  This is
# done by deleting gunzip and zcat and then recreating them as symbolic
# links to gzip.  Using symbolic links, rather than hard links, makes
# it a little more obvious that gunzip and zcat are just other ways of
# calling gzip.
rm $STAGING_DIR/usr/bin/gunzip $STAGING_DIR/usr/bin/zcat
ln -s gzip $STAGING_DIR/bin/gunzip
ln -s gzip $STAGING_DIR/bin/zcat
#
# There is one other file in /usr/bin that is also hard linked.
rm $STAGING_DIR/usr/bin/zcmp
ln -s zdiff $STAGING_DIR/usr/bin/zcmp
#
# Fix the scripts in /usr/bin by removing bogus PATH variable caused by
# installing into the $STAGING_DIR directory.
for FILE in zdiff zforce zgrep zmore znew; do
  mv $STAGING_DIR/usr/bin/$FILE $STAGING_DIR/usr/bin/$FILE.old
  sed -e '/PATH=/d' $STAGING_DIR/usr/bin/$FILE.old > $STAGING_DIR/usr/bin/$FILE
  chmod 755 $STAGING_DIR/usr/bin/$FILE
  rm $STAGING_DIR/usr/bin/$FILE.old
done
#
# Move info and man directories since gzip's configure script does not
# recognize "--infodir=" or "--mandir=" options.
mkdir $STAGING_DIR/usr/share
mv $STAGING_DIR/usr/man $STAGING_DIR/usr/share/man
mv $STAGING_DIR/usr/info $STAGING_DIR/usr/share/info
#
# There are also hard linked manpages that correspond to the hard
# linked binaries above.  Rather than removing them and then making a
# symbolic link, another trick can be used.  Creating a manpage with
# a line like ".so man1/othermanpage.1" will tell the manpage viewer
# to open up another manpage.  This trick was learned from the procps
# package's pkill.1 manpage.
rm $STAGING_DIR/usr/share/man/man1/gunzip.1
rm $STAGING_DIR/usr/share/man/man1/zcat.1
echo ".so man1/gzip.1" >$STAGING_DIR/usr/share/man/man1/gunzip.1
echo ".so man1/gzip.1" >$STAGING_DIR/usr/share/man/man1/zcat.1
rm $STAGING_DIR/usr/share/man/man1/zcmp.1
echo ".so man1/zdiff.1" >$STAGING_DIR/usr/share/man/man1/zcmp.1
#
# Remove the empty /usr/lib directory
rmdir $STAGING_DIR/usr/lib
#
# end of gzip blueprint