majo has asked for the wisdom of the Perl Monks concerning the following question:

Hi everyone. I need some help regarding the code below. I would like to save the latency results into a file whenever a measurement is carried out. Furthermore I would to add a progress bar when the measurements being done. Thank your for your continued support. 

#!/usr//bin/perl -w
use LWP::UserAgent;
use Time::HiRes 'time','sleep';
 
$ua = LWP::UserAgent->new;
$request = new HTTP::Request('GET', "http://http://www.computerhope.co
+m/file.com");
$start = time(  );
$response = $ua->request($request);
$end = time(  );
$latency = $end - $start;
 
print length($response->as_string(  )), " bytes received in $latency s
+econds\n";

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Replies are listed 'Best First'.
Re: SAVE DATA
by Corion (Patriarch) on May 07, 2012 at 07:37 UTC

    Have you looked at LWP::UserAgent::get? It can save the response directly to a file and it also offers you the option of a progress callback.

[reply]
Re: SAVE DATA
by zentara (Cardinal) on May 07, 2012 at 11:07 UTC
    Here is how to monitor progress with LWP 
    #!/usr/bin/perl
use strict;
use warnings;
use LWP::Simple;
use LWP::UserAgent;

my $urlin  = shift || "http://zentara.net/zentara.avi";
my $infile = "zentara1.avi" ;
print "gettin video file : $infile\n";

# don't buffer the prints to make the status update
$| = 1;

open(IN,"> $infile") or die "$_\n"; 

my $ua = LWP::UserAgent->new();
my $received_size = 0;
my $request_time = time;
my $last_update = 0;
my $response = $ua->get($urlin,
                        ':content_cb'     => \&callback,
                        ':read_size_hint' => 8192,
                       );
print "\n";
close IN;

#play the avi file with mplayer
# system( "mplayer $infile" );

#############################################

sub callback {
  my ($data, $response, $protocol) = @_;

  my $total_size = $response->header('Content-Length') || 0;
  $received_size += length $data;

  # write the $data to a filehandle or whatever should happen
  # with it here.
  print IN $data;

  my $time_now = time;

  # this to make the status only update once per second.
  return unless $time_now > $last_update or $received_size == $total_s
+ize;
  $last_update = $time_now;

  print "\rReceived $received_size bytes";
  printf " (%i%%)", (100/$total_size)*$received_size if $total_size;
  printf " %6.1f/bps", $received_size/(($time_now-$request_time)||1)
     if $received_size;
}

__END__

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