skylinedreamer has asked for the wisdom of the Perl Monks concerning the following question:

Hi PerlMonks,

I am trying to batch process sftp file transfers using perl threads. I want to create a directory in the home directory before transferring the file into the server. I am passing the login information to the method while i start the thread. I am able to connect with no probs. I am using a Solaris SPARC Machine

I am able to transfer the file, but am unable to create a folder. My code is as follows with the error msg below. 


sub sub1 
{        
    my @InboundParameters = @_;  
    my $num = $InboundParameters[0];
    print "started thread $num : Establishing connection with $Inbound
+Parameters[1]\n"; 
    my $host = $InboundParameters[2];
    my $sftp = Net::SFTP->new($host, user => $InboundParameters[3], pa
+ssword => $InboundParameters[4], debug => 1)
                    or return ( { 'errors' => "Unable to connect to $h
+ost: " . $@, 'success' => 0 } );
    #$sftp->put("bar", "2345SD/baz");
    $sftp->do_mkdir("ftp2SAT5") or "Cannot make directory: $@" . $sftp
+->error;     
    print "done with thread $num\n";        
    return $num;
}

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Error msg : 
Login completed, opening dummy shell channel.
channel 0: new [client-session]
Requesting channel_open for channel 0.
channel 0: open confirm rwindow 0 rmax 32768
channel 1: new [client-session]
Requesting channel_open for channel 1.
Sending subsystem: sftp
Requesting service subsystem on channel 1.
channel 1: open confirm rwindow 0 rmax 32768
sftp: Sending SSH2_FXP_INIT
sftp: Remote version: 3
sftp: Sent message T:14 I:0
channel 1: rcvd eof
channel 1: output open -> drain
channel 1: obuf empty
channel 1: output drain -> closed
channel 1: close_write
channel 1: rcvd close
channel 1: input open -> closed
channel 1: close_read
channel 1: send close
channel 1: full closed
thread failed to start: Connection closed at ./ftp2sats_v0.1.pl line 8
+1
Bus error (core dumped)

[download]
Seeking your advice. :-)

Replies are listed 'Best First'.
Re: Perl SFTP do_mkdir not able to create directory
by Loops (Curate) on Apr 05, 2013 at 06:37 UTC

    Seems you have to supply the attrs parameter to make do_mkdir happy. Also it returns 0 as a successful return, so "or die ..." will do the wrong thing unfortunately. Your code with a few modifications works okay:

    use strict;
use warnings;
use Net::SFTP;
use Net::SFTP::Attributes;

sub sub1
{
    my @InboundParameters = @_;
    my $num = $InboundParameters[0];
    print "started thread $num : Establishing connection with $Inbound
+Parameters[1]\n";
    my $host = $InboundParameters[2];
    my $sftp = Net::SFTP->new($host, user => $InboundParameters[3], pa
+ssword => $InboundParameters[4], debug => 0)
                    or return ( { 'errors' => "Unable to connect to $h
+ost: " . $@, 'success' => 0 } );
    my $attrs = Net::SFTP::Attributes->new(());
    $sftp->do_mkdir("ftp2SAT5", $attrs) and die;
    print "done with thread $num\n";
    return $num;
}

sub1 qw(1 me localhost my_username my_password);

    [download]
[reply]
[d/l]
      Hi Loops, thank you for your solution. It worked right out of the box. Seems like do_mkdir needs the Attributes to be included as the parameter
[reply]
Re: Perl SFTP do_mkdir not able to create directory
by salva (Canon) on Apr 05, 2013 at 07:30 UTC
    Use Net::SFTP::Foreign instead.

    If you use it combined with Net::OpenSSH you will be even able to reuse the same SSH connections from all the threads: 

    use Net::OpenSSH;
my $ssh = Net::OpenSSH->new($host,
                            user => $InboundParameters[3],
                            password => $InboundParameters[4]);

# then from the threads call...
sub sftp_task {
  my $sftp = $ssh->sftp;
  $sftp->mkdir("ftp2SAT5");
  ...
}

    [download]
[reply]
[d/l]
      Hi salva,

      Thanks for your response. But I am trying to send the file to different hosts. So I wont be able to use the same SSH to do the task I presume.

[reply]
        In that case, you can use Net::OpenSSH::Parallel: 
        use Net::OpenSSH::Parallel;

my $pssh = Net::OpenSSH::Parallel->new;
$pssh->add_host($_) for @hosts;

sub sftp_task {
  my ($host, $ssh) = @_;
  my $sftp = $ssh->sftp;
  $sftp->mkdir("ftp2SAT5")
    or die "unable to create directory: " . $sftp->error;
}

$pssh->all(parsub => &sftp_task);
$pssh->run;

        [download]
[reply]
[d/l]
Re: Perl SFTP do_mkdir not able to create directory
by kcott (Archbishop) on Apr 05, 2013 at 06:28 UTC

    G'day skylinedreamer,

    Welcome to the monastery.

    Try changing 

    $sftp->do_mkdir("ftp2SAT5") or "Cannot make directory: $@" . $sftp->er
+ror;

    [download]

    to (i.e. add die)

    $sftp->do_mkdir("ftp2SAT5") or die "Cannot make directory: $@" . $sftp
+->error;

    [download]

    Update: See ++Loops' reply below.

    to (i.e. change or to and die)

    $sftp->do_mkdir("ftp2SAT5") and die "Cannot make directory: $@" . $sft
+p->error;

    [download]

    If do_mkdir() is failing, you'll now get some indication of why.

    I also note that there's no output from print "started thread ..., but error output shows thread failed to start: ... - you may want to investigate that also.

    -- Ken

[reply]
[d/l]
[select]
      HI Ken, Thanks for your response. I didnt copy paste the whole output from the script. But its infact printing the first line "started thread.."
[reply]

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