I am on Windows Vista Home Premium using Perl 5.8 and OpenSSH 5.5.

I have been using 'Net::SFTP::Foreign' for months without any problems then it stopped working. I have been able to trace the problem to the fact that the module uses 'open2' to start the ssh connection but it seems like the 'in' and 'out' handles are not assigned correctly but seem to be assigned to STDOUT and so the module and my script hang waiting for user input when the input is supposed come from my program not the user.

I put a few lines together to see if 'ssh' will work correctly outside of my program. But it doesn't seem to work even in this simple script: 

use IPC::Open2;

my ($read, $write);

my $pid = open2($read, $write, 'C:/Cygwin/bin/ssh -vv -o PreferredAuth
+entications=publickey user@domain.com');

if ($@)
{
    print STDOUT "error";
}

print $write 'ls';

close $write;

my @lines = <$read>;

close $read;

waitpid $pid, 0;

print STDOUT "Output: @lines\n";

[download]

I am making a connection to my local Linux box using public key authentication which works fine from the command line.

The above script will hang on the line "my @lines = <$read>;" whereas I would expect it to collect the full output and print it.

Any ideas explanation for this behavior of Perl and ssh?

In reply to Open2 and ssh problem by Anonymous Monk

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.