Pipe not working with /usr/bin/grep.  Why is that?

Notice...

        print `/usr/bin/dig -x $ip | grep PTR`; 

....works, but:

        print `/usr/bin/dig -x $ip | /usr/bin/grep PTR`;

....does not.

Another alternative:

        $results = join("", grep(/PTR/, `/usr/bin/dig -x $ip`));

/g

> -----Original Message-----
> From: Robert Thompson [mailto:[EMAIL PROTECTED]]
> Sent: Wednesday, October 31, 2001 5:31 PM
> To: [EMAIL PROTECTED]
> Subject: Outputting shell command to a browser
> 
> 
> Hello,
> 
>       I am working on a script that uses the backticks to execute a 
> shell command, and I want to output the results to a webpage. The 
> problem I am having is that the command I am running seems to take 
> too long and the cgi does not return anything for that variable. Is 
> there a way to make the backtickes wait longer or is there a better 
> way to do this? I have tried the system command, but with similar 
> results of empty values.
> 
>     #!/usr/bin/perl
> 
>     @ips = ("198.182.196.56","216.239.39.100");
>     
>     print "Content-type: text/html\n\n";
>     print "<html>\n<body>\n";
>     print "<pre>\n";
>     
>     foreach $ip (@ips){
>       $results = `/usr/bin/dig -x $ip | /usr/bin/grep PTR`;
>       $test = `echo foo`;
>     
>       print "\n";
>       print "result: \"$results\"\n";
>       print "test:   $test\n";
>       print "\n";
>     
>     }
>     
>     print "</pre>\n";
>     print "</body>\n</html>\n";
> 
> 
> Here is the output from running it from shell, the values are all correct:
> 
>     >./foo.pl 
>     Content-type: text/html
>     
>     <html>
>     <body>
>     <pre>
>     
>     result: "56.196.182.198.in-addr.arpa.  10h37m56s IN PTR  www.linux.org.
>     "
>     test:   foo
>     
>     
>     
>     result: "100.39.239.216.in-addr.arpa.  23h59m16s IN PTR  www.google.com.
>     "
>     test:   foo
>     
>     
>     </pre>
>     </body>
>     </html>
> 
> 
> Here is the source code from the page that is generated, the values 
> are blank:
> 
>     <html>
>     <body>
>     <pre>
>     
>     result: ""
>     test:   foo
>     
>     
>     
>     result: ""
>     test:   foo
>     
>     
>     </pre>
>     </body>
>     </html>
> 
> 
> 
> Thanks,
> 
> =-= Robert Thompson
> 
> PS, I have tried running the cgi again once the IP addresses are 
> cached (so they go quicker), but it still does the same thing so 
> "too slow" is probably not acurate.
> 
> -- 
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