how to use stdin on perl cgi

Question

I am new to perl and I want to use screen input on my script. here is my script and I want the IOS command to be enter from keyboard. can some one show me where I am wrong.the problem i have now the script not read my keyboard input, I am not sure if work on my case. thanks!!

# ### Show ######################################################### 
               $cmd = <STDIN>;
                chomp ($cmd);
               $show_error = "";
              if ($ssh_switch eq 'yes') {
                   ssh_access();
               }
               print "\n",h2($host . ' - ' . $cmd);
                @output=$cmd;
                print hr(),"\n";
               }
}
#########################################################################

Answer 1

CGI is designed to take in a complete HTTP request and then spit out a complete HTTP response.

It simply doesn't work interactively.

If you want to write a script that expects keyboard input, then don't use CGI.

Answer 2

CGI does allow input through STDIN; try CGI->new(\*STDIN).

Though it may not be how you want to enter things. Can you give an example of what your input looks like?

Ah, it looks to me like you want to either:

1. run your script from the command line, like: perl scriptname 'Submit=1&Devices=router1&Devices=router2' and then provide your cisco commands on STDIN (and get html output, which may be inconvenient), or

2. run your script in a browser, in which case you should replace the STDIN usage with an input tag for entering commands and get the commands from that named parameter

Looking again, I see you already have an input tag "search", you just aren't using it. Try replacing <STDIN> with $cgi->param('search') and adding search to the "make sure data was input" check.

Answer 3

In fact, CGI does uses STDIN. It is used to pass the body of POST request. Try this script

#!/usr/bin/perl
print "Content-Type: text/plain\r\n\r\nYou entered: ";
print while <STDIN>;

and POST some data to it, e.g.

$ echo "Just test" | POST http://localhost/yourscript.pl
You entered: Just test

(POST is a program from LWP CPAN distribution)

So you can direct your script with commands read from STDIN, although it is very unsecure as is!