Hello. New here. I'm writing a script to download data via FTP. The script will run in cron every 5 minutes or so, hence the transfer.lock mechanism.

.

My question is, is there a more efficient way to write this? Should I contain some of these things in subs? Here's the code: 

#!/usr/bin/perl -w
use strict;
use Net::FTP;

my $dir = "/tmp";
my $host = "host_with_most";
my $user = "some_user";
my $password = "cool_edgy_pass";
my $ftp_dir = "some/dir";
my $ftp_file_mtime;
my %ftp_file_mtime_hash = ();
my @ftp_file_lst_sorted;
my $oldest_file;
my $lock_dir = "/tmp";
my $dir_handle;
my @tmp_file_list;
my $lock_file = "transfer.lock";
my $start_size_file;
my $running_size_file;
my $ftp_size_check;
my $ftp_file_size;

## changing to the directory from which we will download our file

chdir ($dir);

## opening /tmp directory and reading in file list to array -- ## prob
+ably more efficient way of doing this...

opendir ($dir_handle, $lock_dir) or die("Can't open $lock_dir");
@tmp_file_list = grep { (!/^\./) && -f "$lock_dir/$_" } readdir($dir_h
+andle);
closedir ($dir_handle);

## iterating through array to test elements in list against the ##pres
+ence of the lock file. If present, exit. If the lock file ## isn't pr
+esent then create one and proceed with file transfer

foreach (@tmp_file_list) {
if ($_ eq $lock_file) {
die("Transfer_helper is busy.");
}
}

system ("touch /tmp/transfer.lock");

## creating FTP connection

my $ftp_conn = Net::FTP->new($host) or die("Can't connect to $host");
$ftp_conn->login($user, $password) or die("$user can't login");

## changing the working directory

$ftp_conn->cwd($ftp_dir) or die("can't change to FTP dir $ftp_dir");

## directory listing is obtained with 'ls' command in FTP shell

my @ftp_dir_file_lst = $ftp_conn->ls;

## iterate through the file list
## look at the mtime in epoch seconds for each file
## create a hash as name_of_file => mtime_in_seconds

foreach (@ftp_dir_file_lst) {
$ftp_file_mtime = $ftp_conn->mdtm($_) or die("No files in directory");
$ftp_file_mtime_hash{$_} = $ftp_file_mtime;
}

## sort the hash by value

@ftp_file_lst_sorted = sort {$ftp_file_mtime_hash{$b} <=> $ftp_file_mt
+ime_hash{$a}} keys %ftp_file_mtime_hash;

$oldest_file = $ftp_file_lst_sorted[$#ftp_file_lst_sorted];

## get the size of the file we want to download. Wait 10 ##seconds; if
+ the ftp_file_size doesn't equal the the ##ftp_size_check, sleep
## this is to mitigate downloading of incomplete files

$ftp_file_size = $ftp_conn->size($oldest_file);
sleep(15);

$ftp_size_check = $ftp_conn->size($oldest_file);

while ($ftp_size_check !=  $ftp_file_size) {
sleep(1);
}

## compare start_file_size with running_file_size. Unlink ##transfer.l
+ock when running == start size. Exit program. 

$start_size_file = $ftp_conn->size($oldest_file);

$ftp_conn->get($oldest_file) or die("Can't get file $oldest_file");

$running_size_file = (stat('/tmp/' . $oldest_file))[7];

while ($running_size_file < $start_size_file)
{
sleep(10);
}

unlink('/tmp/' . $lock_file);

[download]

thanks in advance

In reply to improve FTP script by asw

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