#!/sprite/cmds/perl

if ($#ARGV != 1) {
    printf("$#ARGV\n");
    printf("Usage: kdiff oldKernel newKernel\n");
    exit;
}
if (! -e $ARGV[0]) {
    die("File $ARGV[0] does not exist.\n");
}
if (! -e $ARGV[1]) {
    die("File $ARGV[1] does not exist.\n");
}
open(fid, "strings $ARGV[0] |") || die ("Can't open pipe.\n");
while (<fid>) {
    if (/RCS/) {
	($d1,$file, $version) = split;
	$versionArray{$file} = $version;
    }
}

open(fid, "strings $ARGV[1] |") || die ("Can't open pipe.\n");
while (<fid>) {
    if (/RCS/) {
	($d1, $file, $version) = split;
	if (! defined($versionArray{$file})) {
	    $#newFiles++;
	    $newFiles[$#newFiles] = $file;
	} elsif ($version != $versionArray{$file}) {
	    do PrintLog($file, $versionArray{$file}, $version);
	}
	$used{$file} = 1;
    }
}
if ($#newFiles > 0) {
    printf("\nThe following files were added to the new kernel:\n\n");
    for ($i = 0; $i <= $#newFiles; $i++) {
	printf("$newFiles[$i]\n");
    }
}

$headerPrinted = 0;
while (($file, $version) = each(%versionArray)) {
    if (! defined($used{$file})) {
	if ($headerPrinted == 0) {
	    printf(
	"\nThe following files were not used in the new kernel:\n\n");
	    $headerPrinted = 1;
	}
	printf("$file\n");
    }
}

sub PrintLog {
    local($stream);
    local($start) = 0;
    $oldVersion = $_[1];
    $newVersion = $_[2];
    open($stream, "rlog $_[0] |") || die("Can't rlog $_[0]\n");
    printf("******* $_[0]:\n");
    while (<$stream>) {
	($f1, $f2) = split;
	if (($f1 eq "revision") && ($f2 eq $newVersion)) {
	    $start = 1;
	} elsif ($f2 eq $oldVersion) {
	    if ($start == 0) {
		printf("New version %s appears older than old version %s\n",
		    $newVersion, $oldVersion);
		printf("Were the kernel arguments in the correct order?\n");
	    }
	    last;
	}
	if ($start) {
	    print;
	}
    }
    print("\n");
}