如何在Perl中获取文件的上次修改时间？

#!/usr/bin/perl

use strict;
use warnings;

my $filename = "example.txt";

# 获取文件状态信息
my @stat = stat($filename);

# 获取上次修改时间
my $mtime = $stat[9];

# 格式化时间
my ($sec, $min, $hour, $mday, $mon, $year, $wday, $yday, $isdst) = localtime($mtime);
$year += 1900;
$mon += 1;

# 输出上次修改时间
print "File '$filename' was last modified on $year-$mon-$mday $hour:$min:$sec\n";