cc:/sftp/test#
# cat test_sftp.cgi
#!/usr/bin/perl -w

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

my $file       = 'TEST.txt';
my $server     = 'X.X.X.X';
my $user       = 'user';
my $sftp;
my %args       = ( ssh_args => { user            => 'user',
                                 identity_files  => [ '/root/.ssh/id_r
+sa' ],
                                 debug           => 1
                               }
);


$sftp = Net::SFTP->new($server, %args)
     or die "could not open connection to $server\n";

$sftp->put($file, $file) or die "could not upload $file\n";

exit;
[download]

cc:/sftp/test# perl test_sftp.cgi
cc: Reading configuration data /root/.ssh/config
cc: Reading configuration data /etc/ssh_config
cc: Allocated local port 1023.
cc: Connecting to X.X.X.X, port 22.
cc: Remote protocol version 2.0, remote software version 4.0.7.1 SSH S
+ecure Shell Windows NT Server
cc: Net::SSH::Perl Version 1.34, protocol version 2.0.
.inux.ch.bluee.net: No compat match: 4.0.7.1 SSH Secure Shell Windows 
+NT Server
cc: Connection established.
cc: Sent key-exchange init (KEXINIT), wait response.
cc: Algorithms, c->s: 3des-cbc hmac-sha1 none
cc: Algorithms, s->c: 3des-cbc hmac-sha1 none
cc: Entering Diffie-Hellman Group 1 key exchange.
cc: Sent DH public key, waiting for reply.
cc: Received host key, type 'ssh-dss'.
cc: Host 'X.X.X.X' is known and matches the host key.
cc: Computing shared secret key.
cc: Verifying server signature.
cc: Waiting for NEWKEYS message.
cc: Send NEWKEYS.
cc: Enabling encryption/MAC/compression.
cc: Sending request for user-authentication service.
cc: Service accepted: ssh-userauth.
cc: Trying empty user-authentication request.
cc: Authentication methods that can continue: gssapi,publickey,passwor
+d.
cc: Next method to try is publickey.
cc: Trying pubkey authentication with key file '/root/.ssh/id_rsa'
cc: Login completed, opening dummy shell channel.
cc: channel 0: new [client-session]
cc: Requesting channel_open for channel 0.
cc: channel 0: open confirm rwindow 100000 rmax 16384
cc: channel 1: new [client-session]
cc: Requesting channel_open for channel 1.
cc: Sending subsystem: sftp
cc: Requesting service subsystem on channel 1.
cc: channel 1: open confirm rwindow 100000 rmax 16384
[download]

my $file       = '/sftp/test/TEST.txt';
[download]

...............................................................
...............................................................
...............................................................
cc: Sending subsystem: sftp
cc: Requesting service subsystem on channel 1.
cc: channel 1: open confirm rwindow 100000 rmax 16384
Couldn't get handle: Permission denied at test_sftp.cgi line 21
could not upload /sftp/test/TEST.txt
[download]

You are using the same path on both systems. It might help you isolate the problem if you changed the path for one end at a time.

# cat test_sftp.cgi
#!/usr/bin/perl -w

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

my $from       = 'TEST.txt';
my $to         = '/sftp/tmp/TEST.txt';
my $server     = 'X.X.X.X';
my $user       = 'user';
my $sftp;
my %args       = ( ssh_args => { user            => 'user',
                                 identity_files  => [ '/root/.ssh/id_r
+sa' ],
                                 debug           => 1
                               }
);


$sftp = Net::SFTP->new($server, %args)
     or die "could not open connection to $server\n";

$sftp->put($from, $to) or die "could not upload $file\n";

exit;
[download]

Are you running a system with Security Enhanced (SE) Linux (e.g. RedHat)? If so, there may be restrictions on your /sftp directory and/or ssh processes preventing access. If SELinux is preventing access it will probably be logging the faults. Check /var/log/messages (probably).

thx a lot, you are completely right.
There are different paths and the simple script can send a file without problems.

It seems to be a problem with the path on the remote server, I changed my original script:

#!/usr/bin/perl -w

use strict;
use warnings;

use File::Copy;
use File::Find;
use Net::Netrc;
use Net::SFTP;
use MIME::Lite;
use Getopt::Std;
use Mail::Sender;


my $from       = '/srv/*.txt';
my $to         = '/HOME/*.txt';
my $server     = 'X.X.X.X';
my $user       = 'user';
my $sftp;
my %args       = ( ssh_args => { user            => 'user',

                                 identity_files  => [ '/home/.ssh/id_r
+sa' ],

                                 protocol        => '2,1',

                                 debug           => 1,

                               }

);

my $linux = "admin\@domain.net";
my $recipient1 = "recipient1\@domain.net";
my $recipient2 = "recipient2\@domain.net";
my $recipient3 = "recipient3\@domain.net>";


# write a log
BEGIN
{
use CGI::Carp qw(carpout);
my $errorlog = "/srv/logs/transferlog.txt";
open(LOG, ">$errorlog") or die("Unable to open $errorlog: $!\n");
print LOG "Errors:\n";
carpout(*LOG);
}

# create backup subfolder
my @dt = localtime;
my $subfolder_name = ((((1900 + $dt[5]) * 100 + 1 + $dt[4]) * 100 + $d
+t[3]) * 100 + $dt[2]) * 100 + $dt[1];
mkdir "/srv/OUT/$subfolder_name" or die "$subfolder_name: $!";


foreach my $from (</srv/*.txt>) {


# sftp file transfer
$sftp = Net::SFTP->new($server, %args) or die "could not open connecti
+on to $server\n";

$sftp->put($from, $to) or die "could not upload $from\n";


# move files to the backup directory
unless(move("$from", "/srv/OUT/$subfolder_name"))

{
               print STDERR "Oops!  Couldn't move the file: $!";
}

move "/srv/logs/transferlog.txt", "/srv/OUT/$subfolder_name";

               sleep (1 * 5)
}


# send a mail if transfer completed
my $sender = new Mail::Sender
  {smtp => 'localhost', from => $linux};
  $sender->MailFile({to => "$recipient1, $recipient2, $recipient3",
  subject => 'data transfer',
  msg => 'data transfer should be completed',
  file => "/srv/OUT/$subfolder_name/transferlog.txt"});

exit;
[download]


but I'm still getting this problem:

...........................
...........................
...........................
cc: Sending subsystem: sftp
cc: Requesting service subsystem on channel 1.
cc: channel 1: open confirm rwindow 100000 rmax 16384
[Thu Jul 30 13:40:45 2009] cc.cgi: Couldn't get handle: Failure at cc.
+cgi line 60
[Thu Jul 30 13:40:45 2009] cc.cgi: could not upload /srv/28072009.txt
[download]