Question

I started programming in perl few months back and this is my first question on stackoverflow.com. I hope I can get a solution.

So I want to copy some files from an ftp server. The file names are in this format:

abc_201149_cde_07_fgh_include_internal 

In this example the numeric part gets changed on weekly basis, e.g. 201149 says year = 2011 and week = 49. Similarly, 07 says which version it is.

I have copied all the file names into one file called “sdk_link.txt” and I am reading each file name from this and then copying to my local PC:

use Net::FTP;
use File::Copy;
$Login = "<redacted>";
$Pwd = "<redacted>";
$ftpHost = "<redacted>";
$ftpFolder = "/daj/dhakj/ahdakl/abc_201206_def_05";
$ftp=Net::FTP->new($ftpHost,Timeout=>100);
if ($ftp) 
{
    print $ftp->message;
}
$ftp->login($Login,$Pwd);
print $ftp->message;
$ftp->cwd($ftpFolder);
print $ftp->message;
open FILE,"sdk_link.txt" or die $!;
while($test=<FILE>) 
{
    chomp($test);
    #Copy the file
    copy("$test","/testing"); 
}
$ftp->quit;

I want to run this script every week on Windows. How can I make the numeric part change so that the correct files get downloaded?

Answer 1

Well, the obvious answer is to keep a template on file, and insert the correct numbers. For example:

echo abc_%s_cde_%s_fgh_include_internal | 
    perl -MPOSIX -nE 'say sprintf $_, strftime("%Y%U", localtime()), "07";'

Output:

abc_201207_cde_07_fgh_include_internal

So that if you’d have a file with templates, you can use %s to insert strings, and provide arguments either from your own list of arguments, or dynamically, as you prefer. E.g.:

my $year = "2011";
my $week = "49";
my $ver  = "07";  # Strings or numbers does not really matter

open my $fh, '<', "sdk_link.txt" or die $!;

while (<$fh>) {
    my $file = sprintf $_, $year, $week, $ver;
    copy($file, "/testing") or die "Copy failed for file $file: $!";
}

I am not so sure File::Copy::copy works as intended for remote files, but that’s another question. I believe Net::FTP::get() might be what you want.