need a perl script to stop & start program

cccc · 07-20-2005, 07:28 PM

hi

I need a perl script to stop & start program:

# stop PROGRAM

sh /home/ntop.sh stop

# start PROGRAM

sh /home/ntop.sh start

I'd like first stop the program and start it again using apache & browser.

kind regards
cccc

hlyrad · 07-21-2005, 12:18 PM

I assume that what you want to do is allow the user(In reallity the user apache is running under) to stop and start your service?
If this is the case you must give the apache user rights to execute the script.
I use this script via apache/web browser to restart mysql on the same system.

#!/usr/bin/perl
use CGI;
my $query = new CGI;
print $query->header;
print "<html>\n";
print "<head>\n";
print "<title>Repair</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 "</head>\n";
print "<body bgcolor='#c0c0d0'>\n";
print "<center>";
print "<p><br></p>";
print "<p><br></p>";
`mysqladmin -u flush -preload flush-tables`;
`mysqladmin -u flush -preload shutdown`;
system "mysqld_safe --log &";
print "</center>";
print "</body>";
print "</html>";

cccc · 07-21-2005, 02:50 PM

thanks,

I've written following perl script:

Code:

#!/usr/bin/perl -w

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


$bb = system("/home/ntop.sh stop &");

exit($bb);

$cc = system("/home/ntop.sh start &");

exit($cc);

if execute it from command line:

# perl ntop.cgi

then ntop starts,

but via browser, script be executed without errors, but ntop won't start.

# chown www ntop.cgi

doesn't help !

greetings
cccc

keefaz · 07-21-2005, 02:55 PM

Are you sure ntop start from your script in command-line ?
Wasn't it already started ?

Normally it should exit after the exit($bb);

cccc · 07-21-2005, 03:07 PM

sorry, the correct script is:

Code:

#!/usr/bin/perl -w

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

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 "</head>\n";
print "<body bgcolor='#c0c0d0'>\n";
print "<center>";
print "<p><br></p>";
print "<p><br></p>";

my $bb = system("/home/ntop.sh stop");
sleep(5);
$cc = system("/home/ntop.sh start &");

print "</body>";
print "</html>";

exit($cc);

from command line it starts ntop , but via browser ntop doesn't start

hlyrad · 07-21-2005, 03:59 PM

Do any errors show up in your httpd/error_log ?
I suspect youll see an error message like "Access denied"

Try editing your script to capture errors and print them to your browser like so

my $bb = system("/home/ntop.sh stop") or die ($!);
sleep(5);
$cc = system("/home/ntop.sh start &") or die ($!);

Also
# chown www ntop.cgi

will not work if www doesnt have read acces to the home directory.
I would put the script in the cgi-bin directory where www owns everything.

cccc · 07-21-2005, 04:22 PM

I changed the directory and the script, but now I get following error from command line:

Code:

# perl ntop3.cgi
Content-Type: text/html; charset=ISO-8859-1

<html>
<head>
<title>ntop startup script</title>
<STYLE TYPE='text/css'>
h3 { color: red }
a { text-decoration: none; font: bold 14pt/16pt Ariel, serif }a:hover { color: red } /* when mouse is over link */</style>
</head>
<body bgcolor='#c0c0d0'>
<center><p><br></p><p><br></p><h1>Software error:</h1>
<pre>No such file or directory at ntop3.cgi line 22.</pre>
<p>
For help, please send mail to this site's webmaster, giving this error message
and the time and date of the error.

</p>
[Thu Jul 21 23:19:15 2005] ntop3.cgi: No such file or directory at ntop3.cgi line 22.

the new script is:

Code:

#!/usr/bin/perl -w

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

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 "</head>\n";
print "<body bgcolor='#c0c0d0'>\n";
print "<center>";
print "<p><br></p>";
print "<p><br></p>";

my $bb = system("/usr/local/www/cgi-bin/ntop/ntop.sh stop") or die ($!);
sleep(5);
$cc = system("/usr/local/www/cgi-bin/ntop/ntop.sh start &") or die ($!);

print "</body>";
print "</html>";

exit($cc);

hlyrad · 07-21-2005, 05:33 PM

I have edited your script as follows.

#!/usr/bin/perl -w

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

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 "</head>\n";
print "<body bgcolor='#c0c0d0'>\n";
print "<center>";
print "<p><br></p>";
print "<p><br></p>";

my $bb = `/usr/local/www/cgi-bin/ntop/ntop.sh stop` or die ($!);
sleep(5);
my $cc = `/usr/local/www/cgi-bin/ntop/ntop.sh start` or die ($!);
print "</body>";
print "</html>";

You were not checking the return values of $bb or $cc so just using the `` ticks to encapsulate was better.
In fact you could just do
`/usr/local/www/cgi-bin/ntop/ntop.sh stop` or die ($!);
sleep(5);
`/usr/local/www/cgi-bin/ntop/ntop.sh start` or die ($!);
and be done with it
No need to exit($cc)
Background the /usr/local/www/cgi-bin/ntop/ntop.sh start process depends on your script.

Hope this helps

cccc · 07-21-2005, 05:56 PM

thanks a lot, I changed the script, but now I get this error from command line:

Code:

# perl ntop3.cgi
Content-Type: text/html; charset=ISO-8859-1

<html>
<head>
<title>ntop startup script</title>
<STYLE TYPE='text/css'>
h3 { color: red }
a { text-decoration: none; font: bold 14pt/16pt Ariel, serif }a:hover { color: red } /* when mouse is over link */</style>
</head>
<body bgcolor='#c0c0d0'>
<center><p><br></p><p><br></p><h1>Software error:</h1>
<pre>No such file or directory at ntop3.cgi line 22.</pre>
<p>
For help, please send mail to this site's webmaster, giving this error message
and the time and date of the error.

</p>
[Fri Jul 22 00:54:44 2005] ntop3.cgi: No such file or directory at ntop3.cgi line 22.

cccc · 07-21-2005, 06:13 PM

I changed the script a little bit.
this script works well from command line:

Code:

#!/usr/bin/perl -w

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

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 "</head>\n";
print "<body bgcolor='#c0c0d0'>\n";
print "<center>";
print "<p><br></p>";
print "<p><br></p>";

my $bb = system('/usr/local/www/cgi-bin/ntop/ntop.sh stop' or die "cannot stop ntop: $!");
sleep(8);
$cc = system('/usr/local/www/cgi-bin/ntop/ntop.sh start &' or die "cannot start ntop: $!");
print "Status: ",$cc,"\n";

print "</body>";
print "</html>";

exit($cc);

but still cannot execute ntop via browser

in browser I get following output

Status: 0

in error log from Apache, I have:

[Thu Jul 22 00:20:54 2005] [error] [client 192.168.0.5] Permission denied

greetings
cccc

hlyrad · 07-21-2005, 06:21 PM

What is ntop.sh doing?
If it is a service that requires root privilages you may have to do a little more scripting.

keefaz · 07-22-2005, 06:51 AM

Also, did you put the script in a cgi-bin directory as defined
with ScriptAlias in httpd.conf ?

cccc · 07-22-2005, 07:02 AM

Yes, ntop.sh is in the same cgi-bin directory like ntop3.cgi perl script,
but still doesn't help.

keefaz · 07-22-2005, 07:30 AM

Did you check ntop3.cgi permissions (is it executable) ?
Also the hlyrad's note stays valid, does ntop.sh require root privileges ?

cccc · 07-22-2005, 08:35 AM

yes I did:

# chmod 755 ntop3.cgi

# chown nobody ntop3.cgi

or

# chown www ntop3.cgi

but this perl script still cannot start ntop.