in reply to Re^8: show a message only during the sleep time
in thread show a message only during the sleep time

So what's happening is that there's that error, and that's getting sent to the web server (to be sent to the browser) first. But the web server must get valid http headers first. so two things to fix:

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Re^10: show a message only during the sleep time
by cc (Beadle) on Jul 25, 2005 at 18:10 UTC
    I solved the problem.
    There was a problem with JavaScript.

    Now it works perfectly:
    #!/usr/bin/perl -w

use strict;
use warnings;
use CGI;
my $query = new CGI;
use CGI::Carp qw(fatalsToBrowser);

$|=1;
print $query->header;
print "<html>\n";
print "<head>\n";
print "<title>ntop startup script</title>\n";
print "<STYLE TYPE='text/css'>\n";
print "h3 { color: red }\n";
print "a { text-decoration: none; font: bold 14pt/16pt Ariel, serif }"
+;
print "a:hover { color: red } /* when mouse is over link */";
print "</style>\n";
    print "<SCRIPT LANGUAGE = \"JavaScript\">\n";
    print "<!-- \n";
    print "function hideWaitMsg(){
           document.getElementById('wait_msg_text').style.visibility =
+ 'hidden'; }\n";
    print "// -->\n";
    print "</SCRIPT>\n";
print "</head>\n";
print "<center>";
print "<body bgcolor=\"#c0c0d0\" onLoad=\"hideWaitMsg()\"><br>\n";
print "<div id=\"wait_msg_text\">pls wait, ntop will be started !</div
+> \n";
print "<p><br></p>";

system `/usr/local/www/cgi-bin/ntop/ntop.sh stop` or die "cannot stop 
+ntop: $!";
sleep(8);
my $cc = `sudo /usr/local/www/cgi-bin/ntop/ntop.sh start` or die "cann
+ot start ntop: $!";
print "<font face=\"arial,helvetica\" size=2 color=\"#006600\">status:
+</font> ",$cc,"<br><br>\n";

print "<font face=\"arial,helvetica\" size=2 color=\"#FF0000\">
pls do not forget to shutdown, if you're not using </font> \n";
print "\n";
print "<p><br></p>";
print "pls wait for 5 seconds before you click on this link:\n";
print "<br><br>";
print "<a href=\"https://192.168.0.3:3001\"><b><U>NTOP</b></U></a>\n";
print "<p><br></p>";
print "<p><br></p>";
print "<p><br></p>";
print "Maintained by <a href=\"mailto:admin@\domain.net\"><font face=\
+"arial,helvetica\" size=3>
admin</a></font>\n";
print "</center>";
print "</body>";
print "</html>";

exit($cc);

    [download]

    greetings
    cc
[reply]
[d/l]
      system `/usr/local/www/cgi-bin/ntop/ntop.sh stop`

      [download]
      Either pick backquotes (because you want to capture the output) or system (because you want to run the child process), but not both. You're taking the output of ntop, and running it as yet another command, ignoring the results.

      -- Randal L. Schwartz, Perl hacker
      Be sure to read my standard disclaimer if this is a reply.

[reply]
[d/l]
[select]
        you mean ?
        
system "(`/usr/local/www/cgi-bin/ntop/ntop.sh stop`)"  or die "cannot 
+stop ntop: $!";

        [download]
[reply]
[d/l]
        thanks, but can you pls give some more details or post a code how should I change that ?

        greetings
        cc
[reply]

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