In my first page (system.cgi);

<a href="system_process.cgi?action=df">Free Hard Disk Space</a>
[download]

Later in the second page;

print <<"END";
<h1>System Administration</h1>
<table width="450" valign="top" border="0">
   <tr>
    </td>
        <td width="400" valign="top" align="left">
END
        if ($action eq 'df' ) {
                my ($headers_ar, $df_result_ar) = &MySystem::get_df;
                # print out the table headers
                print "<table><tr>\n";
                         foreach my $t_head ( @$headers_ar ) {
                                print "<th>$t_head</th>\n";
                         }
                        # end table header
                        print "</tr>\n";
                        foreach my $hold_ar (@$df_result_ar) {
                         print "<tr>";
                          foreach (@$hold_ar) {
                                print "<td>$_</td>";
                          }
                         print "</tr>";
                        }
                # end table
                print "</table>\n";

        }

print <<"END";
        </td>
   </tr>
</table>
END
[download]

sub get_df {
 my (@headers,@rows);
 # put each line the command returns into an array
 my @df = `df -Ph`;
 # the first element of the array contains the headers
 my $temp_df = shift @df;
 @headers = split (/\s+/, $temp_df);
 foreach (@df) {
  my @parsed_row = split (/\s+/, $_);
  unshift @rows, \@parsed_row;
 }
 return (\@headers, \@rows);
}
[download]

Get Strong Together!!

What you want to do ("I run a system command with perl by pressing a button on browser") is called a CGI script. You need

1. a program called a webserver on the machine where the command is to be executed. Example: apache
2. the perl interpreter installed on the machine where the command is to be executed

when writing the perl script you have to know that:

1. the script can not take normal input from STDIN, use (the module) CGI instead
2. the script can write output to stdout, but the first thing you print out has to be "Content-Type: text/plain\n\n" (the line breaks at the end are very important)
3. there are also some complications with file permissions and users (if we are talking about UNIX here), because the script will be run under the privileges of the webserver, not under your privileges.

I hope that helps in getting you started.

--
Brigitte    'I never met a chocolate I didnt like'    Jellinek
http://www.horus.com/~bjelli/         http://perlwelt.horus.at

isn't it possible to send command line arguments through the URL. My guess is you want to set the form's ACTION to /cgi-bin/yourprogram.cgi?commandlinearguments here. Then the arguments can be got at with the QUERY_STRING variable.

Please kick me in the ass if I'm giving wrong info here.

Perl script is a client-side scripting language similar to Javascript and VBScript. You then:

1. write a function in Perl;
2. surround the Perl function with <script> tags;
3. include the script in the HTML that the browser downloads; and
4. create an HTML button and attach the Perl function to the button's onClick event handler.