Man, I love this! The play by play of a debug session! This is the Matrix meets that bloody burning tower movie which name I can't remember right now.

Go Swiftone!

I can picture you, calm, in control, getting in the zone, hitting the Reload button, quickly typing an answer, then relaxing, leaning back in your chair and sipping your Diet Coke while planning the next move, evaluating all possibilities but in your heart you know that eventually you will prevail.

Meanwhile Motley is sweating, swearing as he made yet another typo, praying for the next answer to come back before this darn qx{} loop crashes again, sweat beads roll from his forefront, empty pizza boxes and half-empty coffee cups litter the floor...

Man... why don't they release more movies like this!

I can't wait for the next episode: "The Loop".

Sorry...

Update: I misread the label, Swiftone only drinks regular Coke, sorry once again.

Ok, here's what I've done. I copied the aml_read line with hardcoded variables inside the loop and it didn't work. Then I put the same line before the loop and it seemed to work. Here is what the code looks like right now including what's commented out with the =cut:

=cut
   $tty = qx{aml_read /l trace /h ftwaeipd0001 /a commproc /s "12/04/2
+000 07:00:00" /b "12/04/2000 08:00:00" /d all | egrep -c -e tty2};
=cut

   for ($i = $TTYFIRST; $i <= $TTYLAST; $i++) {
     Tty_check($i,$start_ts,$end_ts,$selectedserver);
   }

sub Tty_check {

   $tty_string = sprintf( "tty%d", $_[0] );
=cut
   $tty = qx{aml_read /l trace /h $_[3] /a commproc /s $_[1]  /b $_[2]
+ /d all | egrep -c -e $tty_string};
=cut
   $tty = qx{aml_read /l trace /h ftwaeipd0001 /a commproc /s "12/04/2
+000 07:00:00" /b "12/04/2000 08:00:00" /d all | egrep -c -e tty2};
   printf("<TR ALIGN=LEFT VALIGN=TOP>\n");
   printf("<TD>%s</TD>\n",$tty_string);
   chomp($tty);
   printf("<TD>%d</TD>\n",$tty);
   printf("</TR>\n");

}
[download]

So it does appear that there is a problem with the loop, although yesterday I displayed the contents with the qq instead of qx inside the loop and got what I was expecting. What next?

What next?

Good question. I'm somewhat stumped...inside or outside of the loop, it should work the same way. Here's the code I tried (I used echo '' ) around it since I don't have aml_read)

#!/usr/bin/perl -w
use strict;

my $TTYFIRST = 2;
my $TTYLAST = 17;
my $start_ts = '"12/04/2000 07:00:00"';
my $end_ts = '"12/04/2000 08:00:00"';
my $selectedserver = 'ftwaeipd0001';

for (my $i = $TTYFIRST; $i <= $TTYLAST; $i++) {
        Tty_check($i,$start_ts,$end_ts,$selectedserver);
}

sub Tty_check {

        my $tty_string = 'tty'.$_[0];
        my $tty = qx{echo 'aml_read /l trace /h $_[3] /a commproc /s $
+_[1]  /b $_[2] /d all | egrep -c -e $tty_string'};

        chomp($tty);
        print "<TR ALIGN=LEFT VALIGN=TOP>\n";
        print "<TD>$tty_string</TD>\n";
        print "<TD>$tty</TD>\n";
        print "</TR>\n";
}
[download]

And it appear to do the Right Thing. Does it for you?

If so, how about trying to replace the big command with a smaller one. Try just running egrep on a file, or aml_read without piping through egrep. (Still do all of this inside the loop.) I'm guessing now, because this code should work.

I've displayed and compared the lines inside the loop and outside and the strings from this statement look exactly the same: $tty = qx{aml_read /l trace /h ftwaeipd0001 /a commproc /s "12/04/2000 07:00:00" /b "12/04/2000 08:00:00" /d all | egrep -c -e tty2};

I can change both statements to qq inside and outside the loop and it runs and displays the string. But as soon as I change it back to qx the one inside the loop fails....

I guess maybe I should try a different route. Is there any way I can walk through the code as it is executing and see exactly what it is doing?