Well, first off your code reads from STDIN like a c program. CGI is easier to use. Here's your code: 
read(STDIN, $buffer, $ENV{'CONTENT_LENGTH'});

$rating = substr($buffer,0,1);
$table = substr($buffer,1,(length($buffer)+1));

[download]
Here's mine that does the same thing: 
use CGI qw/:standard/;
my ($rating, $table);
if (param()){
 $rating = param('rating');
 $table = param('table');
}

[download]
Try reading the CGI documentation by using perldoc CGI

Especially read the section on debugging on the command line: 

perl -e "use CGI qw/:standard :debug/; if(param()){print  param('you')
+};" you=hello
hello

[download]
And before you are done you should read about tainted data. Your program takes information from the user and turns around and tries to write to a file. That is dangerous: 
perl -Te "use CGI qw/:standard :debug/; $ms=param('you'); if (-f qq($m
+s\.txt)){open(H,qq(>>$ms\.txt))};print <H>; close(H);" you=hello
Insecure dependency in open while running with -T switch at -e line 1.

[download]

Celebrate Intellectual Diversity

In reply to Re: Resources for learning Perl with CGI? by InfiniteSilence
in thread Resources for learning Perl with CGI? by gotpong

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.