634 lines
17 KiB
PHP
634 lines
17 KiB
PHP
<?php
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//
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// FPDI - Version 1.1
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//
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// Copyright 2004,2005 Setasign - Jan Slabon
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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//
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if (!defined ('PDF_TYPE_NULL'))
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define ('PDF_TYPE_NULL', 0);
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if (!defined ('PDF_TYPE_NUMERIC'))
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define ('PDF_TYPE_NUMERIC', 1);
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if (!defined ('PDF_TYPE_TOKEN'))
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define ('PDF_TYPE_TOKEN', 2);
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if (!defined ('PDF_TYPE_HEX'))
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define ('PDF_TYPE_HEX', 3);
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if (!defined ('PDF_TYPE_STRING'))
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define ('PDF_TYPE_STRING', 4);
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if (!defined ('PDF_TYPE_DICTIONARY'))
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define ('PDF_TYPE_DICTIONARY', 5);
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if (!defined ('PDF_TYPE_ARRAY'))
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define ('PDF_TYPE_ARRAY', 6);
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if (!defined ('PDF_TYPE_OBJDEC'))
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define ('PDF_TYPE_OBJDEC', 7);
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if (!defined ('PDF_TYPE_OBJREF'))
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define ('PDF_TYPE_OBJREF', 8);
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if (!defined ('PDF_TYPE_OBJECT'))
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define ('PDF_TYPE_OBJECT', 9);
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if (!defined ('PDF_TYPE_STREAM'))
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define ('PDF_TYPE_STREAM', 10);
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require_once("pdf_context.php");
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class pdf_parser {
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/**
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* Filename
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* @var string
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*/
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var $filename;
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/**
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* File resource
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* @var resource
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*/
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var $f;
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/**
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* PDF Context
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* @var object pdf_context-Instance
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*/
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var $c;
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/**
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* xref-Data
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* @var array
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*/
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var $xref;
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/**
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* root-Object
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* @var array
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*/
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var $root;
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/**
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* Constructor
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*
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* @param string $filename Source-Filename
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*/
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function pdf_parser($filename) {
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$this->filename = $filename;
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$this->f = @fopen($this->filename,"rb");
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if (!$this->f)
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$this->error(sprintf("Cannot open %s !",$filename));
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$this->getPDFVersion();
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$this->c = new pdf_context($this->f);
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// Read xref-Data
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$this->pdf_read_xref($this->xref, $this->pdf_find_xref());
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// Check for Encryption
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$this->getEncryption();
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// Read root
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$this->pdf_read_root();
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}
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/**
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* Close the opened file
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*/
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function closeFile() {
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if (isset($this->f)) {
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fclose($this->f);
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}
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}
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/**
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* Print Error and die
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*
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* @param string $msg Error-Message
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*/
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function error($msg) {
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die("<b>PDF-Parser Error:</b> ".$msg);
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}
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/**
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* Check Trailer for Encryption
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*/
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function getEncryption() {
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if (isset($this->xref['trailer'][1]['/Encrypt'])) {
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$this->error("File is encrypted!");
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}
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}
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/**
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* Find/Return /Root
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*
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* @return array
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*/
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function pdf_find_root() {
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if ($this->xref['trailer'][1]['/Root'][0] != PDF_TYPE_OBJREF) {
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$this->Error("Wrong Type of Root-Element! Must be an indirect reference");
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}
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return $this->xref['trailer'][1]['/Root'];
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}
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/**
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* Read the /Root
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*/
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function pdf_read_root() {
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// read root
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$this->root = $this->pdf_resolve_object($this->c, $this->pdf_find_root());
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}
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/**
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* Get PDF-Version
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*
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* And reset the PDF Version used in FPDI if needed
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*/
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function getPDFVersion() {
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fseek($this->f, 0);
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preg_match("/\d\.\d/",fread($this->f,16),$m);
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$this->pdfVersion = $m[0];
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}
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/**
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* Find the xref-Table
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*/
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function pdf_find_xref() {
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fseek ($this->f, -50, SEEK_END);
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$data = fread($this->f, 50);
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if (!preg_match('/startxref\s*(\d+)\s*%%EOF\s*$/', $data, $matches)) {
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$this->error("Unable to find pointer to xref table");
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}
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return (int) $matches[1];
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}
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/**
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* Read xref-table
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*
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* @param array $result Array of xref-table
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* @param integer $offset of xref-table
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* @param integer $start start-position in xref-table
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* @param integer $end end-position in xref-table
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*/
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function pdf_read_xref(&$result, $offset, $start = null, $end = null) {
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if (is_null ($start) || is_null ($end)) {
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fseek($this->f, $o_pos = $offset);
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$data = trim(fgets($this->f));
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if ($data !== 'xref') {
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fseek($this->f, $o_pos);
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$data = trim(_fgets($this->f, true));
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if ($data !== 'xref') {
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$this->error("Unable to find xref table - Maybe a Problem with 'auto_detect_line_endings'");
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}
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}
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$o_pos = ftell($this->f);
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$data = explode(' ', trim(fgets($this->f)));
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if (count($data) != 2) {
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fseek($this->f, $o_pos);
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$data = explode(' ', trim(_fgets($this->f, true)));
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if (count($data) != 2)
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$this->error("Unexpected header in xref table");
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}
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$start = $data[0];
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$end = $start + $data[1];
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}
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if (!isset($result['xref_location'])) {
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$result['xref_location'] = $offset;
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}
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if (!isset($result['max_object']) || $end > $result['max_object']) {
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$result['max_object'] = $end;
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}
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for (; $start < $end; $start++) {
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$data = fread($this->f, 20); // Spezifications says: 20 bytes including newlines
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$offset = substr($data, 0, 10);
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$generation = substr($data, 11, 5);
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if (!isset ($result['xref'][$start][(int) $generation])) {
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$result['xref'][$start][(int) $generation] = (int) $offset;
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}
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}
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$o_pos = ftell($this->f);
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$data = fgets($this->f);
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if (preg_match("/trailer/",$data)) {
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if (preg_match("/(.*trailer[ \n\r]+)/",$data,$m)) {
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fseek($this->f, $o_pos+strlen($m[1]));
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}
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$c =& new pdf_context($this->f);
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$trailer = $this->pdf_read_value($c);
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if (isset($trailer[1]['/Prev'])) {
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$this->pdf_read_xref($result, $trailer[1]['/Prev'][1]);
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$result['trailer'][1] = array_merge($result['trailer'][1], $trailer[1]);
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} else {
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$result['trailer'] = $trailer;
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}
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} else {
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$data = explode(' ', trim($data));
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if (count($data) != 2) {
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fseek($this->f, $o_pos);
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$data = explode(' ', trim (_fgets ($this->f, true)));
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if (count($data) != 2) {
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$this->error("Unexpected data in xref table");
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}
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}
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$this->pdf_read_xref($result, null, (int) $data[0], (int) $data[0] + (int) $data[1]);
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}
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}
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/**
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* Reads an Value
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*
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* @param object $c pdf_context
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* @param string $token a Token
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* @return mixed
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*/
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function pdf_read_value(&$c, $token = null) {
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if (is_null($token)) {
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$token = $this->pdf_read_token($c);
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}
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if ($token === false) {
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return false;
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}
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switch ($token) {
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case '<':
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// This is a hex string.
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// Read the value, then the terminator
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$pos = $c->offset;
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while(1) {
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$match = strpos ($c->buffer, '>', $pos);
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// If you can't find it, try
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// reading more data from the stream
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if ($match === false) {
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if (!$c->increase_length()) {
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return false;
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} else {
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continue;
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}
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}
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$result = substr ($c->buffer, $c->offset, $match - $c->offset);
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$c->offset = $match+1;
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return array (PDF_TYPE_HEX, $result);
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}
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break;
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case '<<':
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// This is a dictionary.
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$result = array();
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// Recurse into this function until we reach
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// the end of the dictionary.
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while (($key = $this->pdf_read_token($c)) !== '>>') {
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if ($key === false) {
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return false;
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}
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if (($value = $this->pdf_read_value($c)) === false) {
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return false;
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}
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$result[$key] = $value;
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}
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return array (PDF_TYPE_DICTIONARY, $result);
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case '[':
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// This is an array.
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$result = array();
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// Recurse into this function until we reach
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// the end of the array.
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while (($token = $this->pdf_read_token($c)) !== ']') {
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if ($token === false) {
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return false;
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}
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if (($value = $this->pdf_read_value($c, $token)) === false) {
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return false;
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}
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$result[] = $value;
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}
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return array (PDF_TYPE_ARRAY, $result);
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case '(' :
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// This is a string
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$pos = $c->offset;
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while(1) {
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// Start by finding the next closed
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// parenthesis
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$match = strpos ($c->buffer, ')', $pos);
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// If you can't find it, try
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// reading more data from the stream
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if ($match === false) {
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if (!$c->increase_length()) {
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return false;
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} else {
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continue;
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}
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}
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// Make sure that there is no backslash
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// before the parenthesis. If there is,
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// move on. Otherwise, return the string.
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if (isset($c->buffer[$match - 1]) && $c->buffer[$match - 1] !== '\\' ||
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isset($c->buffer[$match - 1]) && $c->buffer[$match - 1] === '\\' && isset($c->buffer[$match - 2]) && $c->buffer[$match - 2] === '\\') {
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$result = substr ($c->buffer, $c->offset, $match - $c->offset);
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$c->offset = $match + 1;
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return array (PDF_TYPE_STRING, $result);
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} else {
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$pos = $match + 1;
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if ($pos > $c->offset + $c->length) {
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$c->increase_length();
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}
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}
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}
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case "stream":
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$o_pos = ftell($c->file)-strlen($c->buffer);
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$o_offset = $c->offset;
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$c->reset($startpos = $o_pos + $o_offset);
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$e = 0; // ensure line breaks in front of the stream
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if ($c->buffer[0] == chr(10) || $c->buffer[0] == chr(13))
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$e++;
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if ($c->buffer[1] == chr(10) && $c->buffer[0] != chr(10))
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$e++;
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if ($this->actual_obj[1][1]['/Length'][0] == PDF_TYPE_OBJREF) {
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$tmp_c = new pdf_context($this->f);
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$tmp_length = $this->pdf_resolve_object($tmp_c,$this->actual_obj[1][1]['/Length']);
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$length = $tmp_length[1][1];
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} else {
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$length = $this->actual_obj[1][1]['/Length'][1];
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}
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$c->reset($startpos+$e,$length);
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$v = $c->buffer;
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$c->reset($startpos+$e+$length+strlen("endstream"));
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return array(PDF_TYPE_STREAM, $v);
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default :
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if (is_numeric ($token)) {
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// A numeric token. Make sure that
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// it is not part of something else.
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if (($tok2 = $this->pdf_read_token ($c)) !== false) {
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if (is_numeric ($tok2)) {
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// Two numeric tokens in a row.
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// In this case, we're probably in
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// front of either an object reference
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// or an object specification.
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// Determine the case and return the data
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if (($tok3 = $this->pdf_read_token ($c)) !== false) {
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switch ($tok3) {
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case 'obj' :
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return array (PDF_TYPE_OBJDEC, (int) $token, (int) $tok2);
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case 'R' :
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return array (PDF_TYPE_OBJREF, (int) $token, (int) $tok2);
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}
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// If we get to this point, that numeric value up
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// there was just a numeric value. Push the extra
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// tokens back into the stack and return the value.
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array_push ($c->stack, $tok3);
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}
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}
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array_push ($c->stack, $tok2);
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}
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return array (PDF_TYPE_NUMERIC, $token);
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} else {
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// Just a token. Return it.
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return array (PDF_TYPE_TOKEN, $token);
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}
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}
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}
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/**
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* Resolve an object
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*
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* @param object $c pdf_context
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* @param array $obj_spec The object-data
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* @param boolean $encapsulate Must set to true, cause the parsing and fpdi use this method only without this para
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*/
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function pdf_resolve_object(&$c, $obj_spec, $encapsulate = true) {
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// Exit if we get invalid data
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if (!is_array($obj_spec)) {
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return false;
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}
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if ($obj_spec[0] == PDF_TYPE_OBJREF) {
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// This is a reference, resolve it
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if (isset($this->xref['xref'][$obj_spec[1]][$obj_spec[2]])) {
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// Save current file position
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// This is needed if you want to resolve
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// references while you're reading another object
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// (e.g.: if you need to determine the length
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// of a stream)
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$old_pos = ftell($c->file);
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// Reposition the file pointer and
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// load the object header.
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$c->reset($this->xref['xref'][$obj_spec[1]][$obj_spec[2]]);
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$header = $this->pdf_read_value($c,null,true);
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if ($header[0] != PDF_TYPE_OBJDEC || $header[1] != $obj_spec[1] || $header[2] != $obj_spec[2]) {
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$this->error("Unable to find object ({$obj_spec[1]}, {$obj_spec[2]}) at expected location");
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}
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// If we're being asked to store all the information
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// about the object, we add the object ID and generation
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// number for later use
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$this->actual_obj =& $result;
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if ($encapsulate) {
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$result = array (
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PDF_TYPE_OBJECT,
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'obj' => $obj_spec[1],
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'gen' => $obj_spec[2]
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);
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} else {
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$result = array();
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}
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// Now simply read the object data until
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// we encounter an end-of-object marker
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while(1) {
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$value = $this->pdf_read_value($c);
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if ($value === false || count($result) > 4) {
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// in this case the parser coudn't find an endobj so we break here
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break;
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}
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if ($value[0] == PDF_TYPE_TOKEN && $value[1] === 'endobj') {
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break;
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}
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$result[] = $value;
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}
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$c->reset($old_pos);
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if (isset($result[2][0]) && $result[2][0] == PDF_TYPE_STREAM) {
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$result[0] = PDF_TYPE_STREAM;
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}
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return $result;
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}
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} else {
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return $obj_spec;
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}
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}
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/**
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* Reads a token from the file
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*
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* @param object $c pdf_context
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* @return mixed
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*/
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function pdf_read_token(&$c)
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{
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// If there is a token available
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// on the stack, pop it out and
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// return it.
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if (count($c->stack)) {
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return array_pop($c->stack);
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}
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// Strip away any whitespace
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do {
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if (!$c->ensure_content()) {
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return false;
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}
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$c->offset += _strspn($c->buffer, " \n\r", $c->offset);
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} while ($c->offset >= $c->length - 1);
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// Get the first character in the stream
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$char = $c->buffer[$c->offset++];
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switch ($char) {
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|
|
|
case '[' :
|
|
case ']' :
|
|
case '(' :
|
|
case ')' :
|
|
|
|
// This is either an array or literal string
|
|
// delimiter, Return it
|
|
|
|
return $char;
|
|
|
|
case '<' :
|
|
case '>' :
|
|
|
|
// This could either be a hex string or
|
|
// dictionary delimiter. Determine the
|
|
// appropriate case and return the token
|
|
|
|
if ($c->buffer[$c->offset] == $char) {
|
|
if (!$c->ensure_content()) {
|
|
return false;
|
|
}
|
|
$c->offset++;
|
|
return $char . $char;
|
|
} else {
|
|
return $char;
|
|
}
|
|
|
|
default :
|
|
|
|
// This is "another" type of token (probably
|
|
// a dictionary entry or a numeric value)
|
|
// Find the end and return it.
|
|
|
|
if (!$c->ensure_content()) {
|
|
return false;
|
|
}
|
|
|
|
while(1) {
|
|
|
|
// Determine the length of the token
|
|
|
|
$pos = _strcspn($c->buffer, " []<>()\r\n\t/", $c->offset);
|
|
|
|
if ($c->offset + $pos <= $c->length - 1) {
|
|
break;
|
|
} else {
|
|
// If the script reaches this point,
|
|
// the token may span beyond the end
|
|
// of the current buffer. Therefore,
|
|
// we increase the size of the buffer
|
|
// and try again--just to be safe.
|
|
|
|
$c->increase_length();
|
|
}
|
|
}
|
|
|
|
$result = substr($c->buffer, $c->offset - 1, $pos + 1);
|
|
|
|
$c->offset += $pos;
|
|
return $result;
|
|
}
|
|
}
|
|
|
|
|
|
}
|
|
|
|
?>
|