Re^6: Long Process Waits Until End to Display Results

Hopefully this group of code snips will show you what is going on.

The first part is where I create the fork. The second part is the lengthy process (one of them). The third part is how I display the results so far as processing is ongoing.

It works fine, except it waits until createCommandFiles() is done before displaying the results instead of displaying the results so far.

my $session = getSessionID();
my $cache = getCacheHandle();
$cache->set($session, [0, $buffer]);

#===== Fork off a child process to do the processing
if (my $pid = fork)
{
  delete_all(); # get rid of old parameters
  param('session', $session);
  print redirect(self_url());
}
elsif (defined($pid))
{
  close STDOUT;
  
  open (STDOUT, "-|");    
  
  #===== Make the command files
  $buffer .= "<strong>Creating command files...</strong><br>";
  $cache->set($session, [0, $buffer]);
  createCommandFiles($cache);
  $buffer .= "<strong>Done creating command files.</strong><p>";
  $cache->set($session, [1, $buffer]);

} # if the pid is defined

sub createCommandFiles($)
{
  my $cache = shift or 
    die "Must supply cache to getVersionReports()!\n";

  #===== Change directory to our directory
  chdir($file_dir) or die "Couldn't chdir to $file_dir";
  
  #===== Make each command file
  foreach my $device (@selected_devices_array)
  {
    my $command = "$mkcmdfile -t \"$device\"";
    system($command) and die
      "Could not run command $command : $!";

    $buffer .=  "Created command file for $device.<br>";

    #===== Update the display cache
    $cache->set($session, [0, $buffer]);
  }

} # end of createCommandFiles()

#===================================================================
#    D I S P L A Y  R E S U L T S
#===================================================================
sub displayPushResults($)
{
  my $session = shift or 
    die "Must supply session id to displayPushResults()!\n";
  my $cache = undef;
  my $data = undef;
  
  #===== Get a cache handle
  $cache = getCacheHandle();
  
  #===== Get the session info
  $data = $cache->get($session);
  
  #===== Check validity of session
  die "Could not reconnect to your session!\n" unless ($data and ref $
+data eq 'ARRAY');
  
  #===== Write the header
  print "Content-type: text/html\n\n";
  print "<html>\n";
  print "<head>\n";
  print "<title>CodePusher.cgi</title>\n";
  print "<meta http-equiv=refresh content=5>\n" if (!($data->[0]));
  print "</head>\n";
  print "<body>\n";
  
  AantsHtml::printUWHeader();
  
  #===== Title
  print "<center><h1>Results</h1></center>\n";
  print "<p><p>\n";
  
  #===== Print the results
  print "$data->[1]";
  
  if (!$data->[0])
  {
    print "<p><font color=red>Still processing... please wait!</font><
+br>"; 
  } # if the code push is not done yet
  
} # displayPushResults()
[download]

Charles Thomas
Madison, WI

Comment on Re^6: Long Process Waits Until End to Display Results Download Code

Replies are listed 'Best First'.
Re^7: Long Process Waits Until End to Display Results by traveler (Parson) on Dec 13, 2004 at 20:42 UTC
At least you need the equivalent of CGI's end_html (probably `</body></html>`) aat then end of displayPushResults per merlyn's example. Try that first. (Presumably you invoke displayPushResults when you get a session with a key.)	[reply] [d/l]
Re^8: Long Process Waits Until End to Display Results by C_T (Scribe) on Dec 13, 2004 at 20:59 UTC
There's other code which writes the footer and closes that stuff out. In any case, I don't believe the absense of a close-body or close-html tag would prevent the display from only being updated when the subroutine finishes. CT Charles Thomas Madison, WI	[reply]


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