Lots of good advice, but I'm surprised no one mentioned avoiding the shell entirely by using the multi-argument forms of system() or exec() to call traceroute directly.

Put together with the above advice and some sugar, you get something like ...

#!/usr/bin/perl -wT

$|++;

use strict;
use CGI qw( header start_html end_html param p );

print header, start_html( "RavenGate TraceRoute Results" );

if ( param('trace') and param('trace') =~ /^[-.0-9a-zA-Z]+$/ ) {
    print p( "Hello There- I am writing this from "
           . "scratch so please be patient. Thanks!" ),
        "<pre>";

    system( "/usr/sbin/traceroute", param('trace') );

    print "</pre>";
    print p( "Oops, there was a problem running traceroute" ) if $?;
} elsif ( param('trace') ) {
    print p( "Oops,", param('trace'), "contains illegal characters" );
} else {
    print p( "Oops, you forgot to give me a host to trace to." );
}

[download]

As for that one line that "doesn't work", you need to escape the pipe (ie, $value =~ s /\|/ /g;).

In reply to Re: CGI and Traceroute by Kanji
in thread CGI and Traceroute by Anonymous Monk

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