如何使用Perl以一些安全性和最少的资源提供映像？

该查询将由“somescript.pl?img=image.png”生成

#!/usr/bin/perl -Tw
use strict;
use warnings;
use CGI;

#I should drop warnings after all is said and done. Also name my vars generically. Right?
#I dont know if this query method will work or is even the best method.
$query = new CGI;
my @img = $query->param;
if ( $_ eq "img" ) { my $file = $query->param($_); }
if ( $_ ne "img" ) {    ## I will send to an error sub that serves up a error image
}

# Prob a one liner to take care of the above. Not within my ability though.
# Still figuring all this out here.. Very verbose sorry...
# I will strip everything but lowercase alpha and the "."
# with s =~ /[something like A-Z] I will look it up //g;
# Still.. prob all above will fit in a one liner by a PERL guru!

# Below is related to -Taint,I was told this is important to use the -T.
$ENV{PATH} = "bin:/usr/bin";
delete( $ENV{qw(IFS CDPATH BASH_ENV ENV)} );

# now I will grab the images extension.
my $ext = ( $file =~ m/[^.]+$/ )[0];

#I was informed to use the "three" but,I am unsure what that means.
# My attempt based on my reading many posts here.

my $length = ( stat($file) )[10];
my $image  = do {
    local $/ = undef;
    print "Content-type: image/$extn";
    print "Content-length: $length nn";
    binmode STDOUT;
    open( FH,"<",$file ) || die "Could not find $file: $!";
    my $buffer = "";
    while ( read( FH,$buffer,10240 ) ) {
        print $buffer;
    }
    close(FH);
};

正如你所看到的,我在这里的尝试显然是初学者.

我在堆栈溢出中找到了很好的建议.我感谢过去和现在的所有人.