Reputation: 11933
My Google fu is failing me. How do I use Perl to serve up an already generated image?
Example:
<html><body><img src="getimage.pl"></body></html>
What goes in getimage.pl?
Upvotes: 3
Views: 7873
Reputation: 281875
Here you go:
#!/usr/bin/perl -w
my $file = "inner-nav.gif";
## my $length = (stat($file)) [10];
## (stat($file)) [10]; is the inode change time in seconds since 00:00 January 1, 1970 GMT.
my $length = (stat($file)) [7];
print "Content-type: image/gif\n";
print "Content-length: $length \n\n";
binmode STDOUT;
open (FH,'<', $file) || die "Could not open $file: $!";
my $buffer = "";
while (read(FH, $buffer, 10240)) {
print $buffer;
}
close(FH);
Upvotes: 7
Reputation: 135
One user asked if there was something missing. I think so. exit 1;
is missing at the end of the script. Here's my revised version (lol I only added in the exit 1;
)
#!/usr/bin/perl -w
my $file = "inner-nav.gif";
my $length = (stat($file)) [10];
print "Content-type: image/gif\n";
print "Content-length: $length \n\n";
binmode STDOUT;
open (FH,'<', $file) || die "Could not open $file: $!";
my $buffer = "";
while (read(FH, $buffer, 10240)) {
print $buffer;
}
close(FH);
exit 1;
A better way, I think anyway, is to do this:
#!/usr/bin/perl
# must haves!
use strict;
use warnings;
use CGI;
my $cgi = new CGI; # used in 'getParam($)' for getting URL paramaters
use lib "pm"; # my own perl modules library
use user; # my user related functions
use dir; # my directory handling functions
# these will be used for $fn if $fn not found, read error, or no user
my $file_not_found = "/img_srvr/error-file-not-found.jpg";
my $read_error = "/img_srvr/error-reading-image.jpg";
my $no_such_user = "/img_srvr/error-no-such-user.jpg";
# the premise of the following is to capture all input into separate vars
# verify that each element is correct, and then spit out the image.
# for my site. remove it if you like. see below for getParam($) definition
my $uid = getParam("uid");
if (not userExists($uid)) { printImage($no_such_user); exit 1; }
my $folder = "/img_srvr/$uid"; # the folder where the images are stored
my $fn = getParam("img"); # see below for definition
my $path = "$folder/$fn"; # this, too, _is_ better
if (not fileExists($path))
{ printImage($file_not_found); exit 1; } else
{ printImage($path); }
exit 1;
#########################################################################
######################
sub printImage($) {
# be sure to do your error checking BEFORE calling this. it'll just
# blindly rip along.
my $fn = $_[0];
my $type = getType($fn); # see sub below
my $buffer = "";
print "content-type: image/$type\n"; # these are awful, but ok for now
print "\n"; # separate just in case we want to add more to the header.
binmode STDOUT;
open my $FH, "<", $fn or die "$!";
while (read ($FH, $buffer, 10240)) {
print $buffer; # prefer NOT to print as I read...
}
close $FH;
# return $OUTPUT; # this would be better, no?
}
######################
# there's gotta be a better way, spock!
sub getType($) {
my $f = $_[0];
if ($f =~ /\.gif$/i) { return "gif"; }
if ($f =~ /\.jpg|\.jpeg$/i) { return "jpeg"; }
if ($f =~ /\.png$/i) { return "png"; }
return "bmp";
}
sub getParam($) {
return $cgi->param($_[0]);
}
Oh! And this might be a useful link (mime types!):
====
Finally, using the above printImage
function I made, is it possible to 'resize' the image? If so, how? I do not want to install another package, or anything like that. It has to be simple.
Upvotes: 0
Reputation: 31
A small correction to the code -- the stat command provided did not return the length of the file. Some browsers did not care, but others would fail to load the image. (stat($file))[10] is 'ctime', not the length of the file.
#!/usr/bin/perl -w
my $file = "inner-nav.gif";
my $length = -s $file;
print "Content-type: image/gif\n";
print "Content-length: $length \n\n";
binmode STDOUT;
open (FH,'<', $file) || die "Could not open $file: $!";
my $buffer = "";
while (read(FH, $buffer, 10240)) {
print $buffer;
}
Upvotes: 3
Reputation: 1
A simple solution that handles png or jpg files. Lookup the latest version of GD if you want to do more filetypes.
http://www.perlmonks.org/?node_id=18565
#sub serveImage
{
use GD;
my ( $localPath ) = @_;
if( $localPath =~ /\.png/i )
{
print "Content-type: image/png\n\n";
binmode STDOUT;
my $image = GD::Image->newFromPng( $localPath );
print $image->png;
}
else
{
print "Content-type: image/jpeg\n\n";
binmode STDOUT;
my $image = GD::Image->newFromJpeg( $localPath );
print $image->jpeg(100);
}
}
Upvotes: 0
Reputation: 13903
WWW FAQs: "How do I output images from a Perl/CGI or PHP script" should get you going in the right direction. You will have to forgive me for not answering your question directly as I haven't touched Perl in about 5 years.
Upvotes: 2
Reputation:
Something like this ...
#!/usr/bin/perl
use strict;
use warnings;
use CGI;
my $gfx='';
$gfx = makeImage();
print CGI::header( type=>'image/png',
expires=>'+1m',
content_length=>length($gfx)});
print $gfx;
Upvotes: 6