I am getting a premature end of script headers error when running a
particular script from a browser. It runs fine the command line, printing
the proper header and all.
I use the CGI.pm module to print the header, and do not print anything
prior to the header. I do not understand why this error occurs. The code
is below.
Any suggestions anyone can offer would be appreciated.
#!/usr/local/bin/perl
###############################################################################
# cube_root.cgi
# by Peter Cline 02-10-2002
# Implements Martin Gardner's description of how one can immediately determine
# a cube root given a cube of an integer between 1 and 100
# The program assumes that the number provide is indeed a cube. Therefore if
# a number which is not a cube is given,the program will return the root of the
# nearest cube. This is consistent with how a person would perform, unless
# one took the time to memorize all 100 cubes
###############################################################################
use strict;
use CGI qw(:standard);
my $q = new CGI;
my $cubed = $q->param("cubed"); #get user provided
cube from cgi parameters
print header;
my @cubes = qw(0 1 8 27 64 125 216 343 512 729 1000); #here the program
"memorizes" the first 10 cubes.
# 0 is included
because Perl uses 0 indexed arrays
my $root = "";
if ($cubed > 1000000) { #check to see if the number is
bigger then the cube of 100
print<<HTML; #if so, an error screen is printed.
<html>
<head>
<title>Error Page</title>
</head>
<body bgcolor="#ffffff">
<h3>Oops,your number was too large!</h3>
<p>I'm sorry but I am only able to deal with cubes of numbers between 1
and 100. The number you gave me is too large!. Please try
again. If you
use a number in the proper range, I promise I won't disappoint.</p>
<form method="POST" action="/cgi-bin/cube_root.cgi">
If you please, pick an integer between 1 and 100, cube it and put
the result here:
<input type="text" name="cubed" size="10" maxlength="10">
<input type="submit" value="Find the Cube Root!">
</form>
<a href="/D.BioInformatics_Spring2002/D.Students/peterc/">Return to
My Homepage</a>
</body>
</html>
HTML
} else { #otherwise we calculate the cube
if ($cubed =~ /([145690])$/) { #if a cube ends in 0,1,4,5,6 or 9 so
will its root
$root = $1;
} elsif ($cubed =~ /([2378])$/) { #if a cube ends in 2,3,7 or 8 its
root ends in 10 - last digit of cube
$root = 10 - $1;
}
$cubed = substr ($cubed,0,length($cubed) - 3); #create modified
number by removing the last three digits
for (1..10) { #find 2 cubes between
which modified number falls and prepend
#root of smaller cube
to the root we are determining
my $next = $_ + 1;
if ($cubed > $cubes[$_] and $cubed < $cubes[$next]) {
$root = $_.$root;
last;
}
}
print<<HTML; #print
confirmation page
<html>
<head>
<title>Success Page</title>
</head>
<body bgcolor="#ffffff">
<h3>I have an answer for you</h3>
<p>The cube root of the number you provided is $root. If you'd
like to try again, you may do so below.
Otherwise, use the link below the form to return to my homepage.</p>
<form method="POST" action="/cgi-bin/cube_root.cgi">
If you please, pick an integer between 1 and 100, cube it and put
the result here:
<input type="text" name="cubed" size="10" maxlength="10">
<input type="submit" value="Find the Cube Root!">
</form>
<a href="/D.BioInformatics_Spring2002/D.Students/peterc/">Return to
My Homepage</a>
</body>
</html>
HTML
}
Peter Cline
Software Engineer
New York Times Digital
