#!/usr/bin/perl -w

# original script by Jacob Meuser <jakemsr@clipper.net>
# You are free to use this as you please
# This code comes with ABSOLUTELY NO WARRANTY
# USE AT YOUR OWN RISK

# To use: Get patch-2.2.15pre14-ppscsi1.gz from ftp://people.redhat.com/twaugh/parport/.
#         Gunzip the patch. (gunzip patch-2.2.15pre14-ppscsi1.gz)
#         Become root. (su root)
#         Put the patch in /usr/src. (cp patch-2.2.15pre14-ppscsi1 /usr/src/)
#         Run this script. (./patch_ppscsi.pl)

# This was wdeveloped under perl-5.6.0 on a i686 running Debian linux

# NOTE: This script will fail if you don't have "linux" in the name of your source tree

use strict;

print qq (\nppSCSI patch program\n\n);

chdir "/usr/src";

if (-d "linux") {
    if (!(-l "linux")) {
	print qq (It is recomended that your linux kernel source be in a 
                  directory other than "linux", and that a symlink named 
                  "linux" points to your source\n);
        my $yorn = "q";
	while (($yorn ne "y") and ($yorn ne "n")) {
	    print qq (\nWould you like me to do this? [yn] );
	    $yorn = <STDIN>;
	    chomp $yorn;
	}
        if ($yorn eq "y") {
	    print qq (What would you like "linux" to be renamed as? );
            my $new_name = <STDIN>;
	    chomp $new_name;
	    rename "linux", "$new_name";
            symlink "$new_name", "linux";
	}
    }
}

opendir (SRCDIR, ".") or die "Could not open /usr/src: $!\n";
my @linux = grep (/linux/, readdir SRCDIR);
closedir SRCDIR;

print qq (Num\tDirectory\n);
print qq (--------------------\n);
my @linux_dirs;
my $count = 0;
foreach (@linux) {
    next if (-l); 
    if (-d) {
	push @linux_dirs, $_;
        print qq ($count\t$_\n);
        $count++;
    }
}

my $high = $count - 1;
die "\nCould not find linux source tree, sorry!\n"if ($high < 0);

my $tree = -1;
while (($tree < 0) or ($tree > $high)) {
    print qq (\nWhat number corresponds to the linux source tree to patch? [0-$high] );
    $tree = <STDIN>;
    chomp $tree;
}

my $new = $linux_dirs[$tree];

if (-l "linux") {
    my $link = readlink "linux";
    if ($link ne "$new") {
        print qq (The "linux" symlink does not appear to point at $new. It needs to.\n);
        print qq (Changing symlink.\n);
        unlink "linux";
        symlink "$new", "linux";
    }
} else {
    print qq (You need a symlink.\n);
    symlink "$new", "linux";
    print qq (Made symlink\n);
}

my $patch_file = "patch-2.2.15pre14-ppscsi1";
open (PATCH, "$patch_file") or die "Could not open $patch_file: $!\n";
my @lines = <PATCH>;
close (PATCH);

my $new_patch = "ppSCSI_patch_ppscsi";
open (NEWPATCH, ">$new_patch") or die "Could not could not open $new_patch for writing: $!\n";
foreach (@lines) {
    s/linux-2.2.15pre14/$new/;
    print NEWPATCH;
}

print qq (Beginning patch ... \n);

system ("patch -p0 < $new_patch");

print qq (Done!\n);

exit (0);