[Expectperl-discuss] Debugging timeouts

[ncmudbug <jam...@em...>]

This is my first post. I tried searching for "timeout" but as you can
imagine, the output was pretty voluminous! However, I didn't see any other
questions similar to mine in the first several pages. Knowing my luck,
somebody asked just the question on the page beyond where I stopped looking.
>-(  If so, just send me the link to the answer.
I am using Perl-Expect to perform unattended tasks on a remote Linux
machine. I am getting some timeout error on simple things that have a
generous timeout value for it. For example, $mountpt is set to '/media/tmp'.
I have the following call:

$exists = &conn::run_and_expect ( $ssh, 2, "[ -d $mountpt ]" );

The code for &run_and_expect follows:

sub run_and_expect
{
    my ( $conn, $timeout, $cmd ) = @_;

    my $command = "$cmd >/dev/null 2> /tmp/err && echo SUCCESS || echo
FAIL\n";
    my $success = 0;
    my $got_error = 0;
    my $got_prompt = 0;

    $conn->clear_accum ( );
    print $conn $command;
    $conn->expect ( $timeout, [ "\nSUCCESS\r\n", sub {
                                                $success = 1;
                                                exp_continue;
                                                } ],
                              [ "\nFAIL\r\n", sub {
                                                my $ssh = shift;
                                                $success = 0;
                                                print $ssh "/bin/cat
/tmp/err\n";
                                                $ssh->expect ( 5,
                                                            [ '-re',
'\n.*\r\n',
                                                            sub {
                                                                my $error =
$ssh->match ( );
                                                                chomp
$error;
                                                                $got_error =
1;
                                                               
&log::append_log ( $log::NO_ECHO, "$cmd returned with:$error" );
                                                               
exp_continue;
                                                            } ],
                                                            [ '-re',
$prompt,
                                                            sub {
                                                                if ( !
$got_error ) {
                                                                   
&log::append_log ( $log::NO_ECHO, "$cmd failed" );
                                                                   
&log::append_log ( $log::NO_ECHO, "no error message found" );
                                                                   
$got_prompt = 1;
                                                                }
                                                            } ]
                                                            );
                                                $success = 0;
                                                exp_continue;
                                                } ],
                              [ '-re', $prompt, sub {
                                                $success = $success;
                                                $got_prompt = 1;
                                                } ],
                              timeout=> sub {
                                                if ( ! $got_prompt ) {
                                                    &log::append_log (
$log::NO_ECHO, "we timed out running $cmd" );
                                                    $success = 0;
                                                }
                                            }
                        );
    return $success;
}

I am getting TIMEOUT errors:

spawn id(4): Does `[ -d /media/tmp ] >/dev/null 2> /tmp/err && echo SUCCESS
|| echo FAIL\r\n'^M
match:^M
  pattern #1: -re `\nSUCCESS\r\n'? No.^M
  pattern #2: -re `\nFAIL\r\n'? No.^M
  pattern #3: -re `(?-xism:# $)'? No.^M
^M
Waiting for new data (2 seconds)...^M
TIMEOUT^M
Calling timeout function CODE(0x8655adc)...^M
Returning from expect with TIMEOUT or EOF^M
Starting EXPECT pattern matching...^M

The machine is very lightly loaded - in fact, I am the only user logged on.
The command shows up in the history of the remote machine. When I run the
command by hand, it comes back instantly regardless of whether the directory
is there or not (obviously, just checking for the existence of a directory
is a trivial task and two seconds should be much more time than is necessary
for that). Incidentally, this problem happens with other commands that
should have no problem finishing during the timeout period. It seems that it
doesn't make any difference what the timeout value is that sometimes, the
command will still timeout regardless.

Is there some way I can debug what is causing this simple command to time
out? Any help would be GREATLY appreciated =). 
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