#!/usr/bin/perl

use strict;
use warnings;

use Getopt::Long;

my $USAGE = "Usage: $0 [-r <build root>] <file>\n";

my $buildroot = "";
GetOptions("r|root=s" => \$buildroot) or die $USAGE;
if (scalar(@ARGV) != 1) {
	die $USAGE;
}
if ($buildroot) {
	$buildroot .= "/";
}

my $fn = shift @ARGV;
my $out = `sha512hmac "$buildroot$fn"`;
if ($?) {
	exit 1;
}
my @t = split(" ", $out);
my $hmac = $t[0];

(my $hmacfn = "$buildroot$fn") =~ s|([^/]*)$|.$1.hmac|;
open(my $fd, '>', $hmacfn) or die "$0: Cannot open $hmacfn: $!\n";
print $fd "$hmac  $fn\n";
close($fd);
exit 0;