Using File::Util will do this for you automatically.

use File::Util;

my $ftl = File::Util->new();

# write to a file: (It is automatically locked)

$ftl->write_file(file => '/foo/bar/baz.txt', content => 'blah blah bla
+h');

# read from a file: (It is automatically locked)

my $content = $ftl->load_file("/foo/bar/baz.txt");

# to get an open filehandle that is automatically locked,
# see http://search.cpan.org/~tommy/File-Util-3.30_003/Util.pod#open_h
+andle
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