#!/usr/bin/env perl

use strict;
use warnings;

use 5.010_001;

use English qw( -no_match_vars );    # avoid regex performance penalty
use File::Copy;
use File::Temp qw(tempfile);
use Readonly;

Readonly my $STAT_INODE => '1';
Readonly my $STAT_SIZE  => '7';

my $tmp_fh = fetch();
store($tmp_fh);
exit 0;

sub fetch {
	my $src_file = '/etc/services';
	show_filestats('FETCH', $src_file);

	my ( $tmp1_fh, $tmp1_filename ) = tempfile();
	unlink $tmp1_filename; # 

	copy $src_file, $tmp1_fh
		or die "$ERRNO\n";
	show_filestats('FETCH', $tmp1_fh);

	return $tmp1_fh;
}

sub store {
	my $tmp1_fh = shift;
	my $tmp2_file = File::Temp->new( TEMPLATE => '/tmp/services.XXXX', UNLINK => 0 );
	my $dst_file = '/tmp/services_copy';

	show_filestats('STORE', $tmp1_fh);
	show_filestats('STORE', $tmp2_file);

	print "[STORE] Copying filehandle tmp1 ($tmp1_fh) to tmp2 ($tmp2_file) file.\n"
	  or croak();

	copy $tmp1_fh, $tmp2_file
		or die "E: $ERRNO\n";

	show_filestats('STORE', $tmp1_fh);
	show_filestats('STORE', $tmp2_file);

	# apply permissions and ACLs
	rename $tmp2_file, $dst_file
	  or die "E: $ERRNO\n";
}

sub show_filestats {
	my $id = shift;
	my $fh = shift;

	my ( $inode, $size ) = ( stat $fh )[ $STAT_INODE, $STAT_SIZE ];
	print "[$id] The file '$fh' has inode $inode and size $size\n"
	  or croak();

	return;
}