...
my $start = quotemeta "$file$yesterday";
my ($file) = $sftp->glob(qr/^$start\d{6}$/, names_only => 1);
...

##</code><code>##

$sftp->setcwd($ai_dir);
my $starts = join('|', map quotemeta, @ai_files_day);
$sftp->mget(qr/^(?:$starts)$yesterday\d{6}$/, $ai_dest_day);