Question

I use php and ghostscript to convert pdf to image and show

<?php
if(empty($_GET['page'])) die;
$numPage=$_GET['page'];
header('Content-type:image/jpeg');
system("gs ".
"-dNOPAUSE ".
"-sDEVICE=jpeg ".
"-dFirstPage={$numPage} ".
"-dLastPage={$numPage} ".
"-sOutputFile=%stdout ".
"-dJPEGQ=90 ".
"-r100x100 ".
"-q file.pdf ".
"-c quit");
?>

thanks for your answers

Answer 1

1. Use passthru instead of system
   According to PHP Manual This function[passthru()] should be used in place of exec() or system() when the output from the Unix command is binary data which needs to be passed directly back to the browser.

2. change %stdout to -
   gs man page:

   You can also send output to stdout for piping with the switch

           -sOutputFile=-
   

the code below should fix it.

<?php

if(empty($_GET['page'])) die;

$numPage=$_GET['page'];

header('Content-type:image/jpeg');

passthru("gs ".
"-dNOPAUSE ".
"-sDEVICE=jpeg ".
"-dFirstPage={$numPage} ".
"-dLastPage={$numPage} ".
"-sOutputFile=- ".
"-dJPEGQ=90 ".
"-r100x100 ".
"-q file.pdf ".
"-c quit");

?>