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|
<?php
//
// FPDI - Version 1.2
//
// Copyright 2004-2007 Setasign - Jan Slabon
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
if (!defined ('PDF_TYPE_NULL'))
define ('PDF_TYPE_NULL', 0);
if (!defined ('PDF_TYPE_NUMERIC'))
define ('PDF_TYPE_NUMERIC', 1);
if (!defined ('PDF_TYPE_TOKEN'))
define ('PDF_TYPE_TOKEN', 2);
if (!defined ('PDF_TYPE_HEX'))
define ('PDF_TYPE_HEX', 3);
if (!defined ('PDF_TYPE_STRING'))
define ('PDF_TYPE_STRING', 4);
if (!defined ('PDF_TYPE_DICTIONARY'))
define ('PDF_TYPE_DICTIONARY', 5);
if (!defined ('PDF_TYPE_ARRAY'))
define ('PDF_TYPE_ARRAY', 6);
if (!defined ('PDF_TYPE_OBJDEC'))
define ('PDF_TYPE_OBJDEC', 7);
if (!defined ('PDF_TYPE_OBJREF'))
define ('PDF_TYPE_OBJREF', 8);
if (!defined ('PDF_TYPE_OBJECT'))
define ('PDF_TYPE_OBJECT', 9);
if (!defined ('PDF_TYPE_STREAM'))
define ('PDF_TYPE_STREAM', 10);
require_once("pdf_context.php");
require_once("wrapper_functions.php");
class pdf_parser {
/**
* Filename
* @var string
*/
var $filename;
/**
* File resource
* @var resource
*/
var $f;
/**
* PDF Context
* @var object pdf_context-Instance
*/
var $c;
/**
* xref-Data
* @var array
*/
var $xref;
/**
* root-Object
* @var array
*/
var $root;
/**
* Constructor
*
* @param string $filename Source-Filename
*/
function pdf_parser($filename) {
$this->filename = $filename;
$this->f = @fopen($this->filename, "rb");
if (!$this->f)
$this->error(sprintf("Cannot open %s !", $filename));
$this->getPDFVersion();
$this->c = new pdf_context($this->f);
// Read xref-Data
$this->pdf_read_xref($this->xref, $this->pdf_find_xref());
// Check for Encryption
$this->getEncryption();
// Read root
$this->pdf_read_root();
}
/**
* Close the opened file
*/
function closeFile() {
if (isset($this->f)) {
fclose($this->f);
unset($this->f);
}
}
/**
* Print Error and die
*
* @param string $msg Error-Message
*/
function error($msg) {
die("<b>PDF-Parser Error:</b> ".$msg);
}
/**
* Check Trailer for Encryption
*/
function getEncryption() {
if (isset($this->xref['trailer'][1]['/Encrypt'])) {
$this->error("File is encrypted!");
}
}
/**
* Find/Return /Root
*
* @return array
*/
function pdf_find_root() {
if ($this->xref['trailer'][1]['/Root'][0] != PDF_TYPE_OBJREF) {
$this->error("Wrong Type of Root-Element! Must be an indirect reference");
}
return $this->xref['trailer'][1]['/Root'];
}
/**
* Read the /Root
*/
function pdf_read_root() {
// read root
$this->root = $this->pdf_resolve_object($this->c, $this->pdf_find_root());
}
/**
* Get PDF-Version
*
* And reset the PDF Version used in FPDI if needed
*/
function getPDFVersion() {
fseek($this->f, 0);
preg_match("/\d\.\d/",fread($this->f,16),$m);
$this->pdfVersion = $m[0];
}
/**
* Find the xref-Table
*/
function pdf_find_xref() {
fseek ($this->f, -min(filesize($this->filename),1500), SEEK_END);
$data = fread($this->f, 1500);
$pos = strlen($data) - strpos(strrev($data), strrev('startxref'));
$data = substr($data, $pos);
if (!preg_match('/\s*(\d+).*$/s', $data, $matches)) {
$this->error("Unable to find pointer to xref table");
}
return (int) $matches[1];
}
/**
* Read xref-table
*
* @param array $result Array of xref-table
* @param integer $offset of xref-table
* @param integer $start start-position in xref-table
* @param integer $end end-position in xref-table
*/
function pdf_read_xref(&$result, $offset, $start = null, $end = null) {
if (is_null ($start) || is_null ($end)) {
fseek($this->f, $o_pos = $offset);
$data = trim(fgets($this->f,1024));
if (strlen($data) == 0)
$data = trim(fgets($this->f,1024));
if ($data !== 'xref') {
fseek($this->f, $o_pos);
$data = trim(_fgets($this->f, true));
if ($data !== 'xref') {
if (preg_match('/(.*xref)(.*)/m', $data, $m)) { // xref 0 128 - in one line
fseek($this->f, $o_pos+strlen($m[1]));
} elseif (preg_match('/(x|r|e|f)+/', $data, $m)) { // correct invalid xref-pointer
$tmpOffset = $offset-4+strlen($m[0]);
$this->pdf_read_xref($result, $tmpOffset, $start, $end);
return;
} else {
$this->error("Unable to find xref table - Maybe a Problem with 'auto_detect_line_endings'");
}
}
}
$o_pos = ftell($this->f);
$data = explode(' ', trim(fgets($this->f,1024)));
if (count($data) != 2) {
fseek($this->f, $o_pos);
$data = explode(' ', trim(_fgets($this->f, true)));
if (count($data) != 2) {
if (count($data) > 2) { // no lineending
$n_pos = $o_pos+strlen($data[0])+strlen($data[1])+2;
fseek($this->f, $n_pos);
} else {
$this->error("Unexpected header in xref table");
}
}
}
$start = $data[0];
$end = $start + $data[1];
}
if (!isset($result['xref_location'])) {
$result['xref_location'] = $offset;
}
if (!isset($result['max_object']) || $end > $result['max_object']) {
$result['max_object'] = $end;
}
for (; $start < $end; $start++) {
$data = ltrim(fread($this->f, 20)); // Spezifications says: 20 bytes including newlines
$offset = substr($data, 0, 10);
$generation = substr($data, 11, 5);
if (!isset ($result['xref'][$start][(int) $generation])) {
$result['xref'][$start][(int) $generation] = (int) $offset;
}
}
$o_pos = ftell($this->f);
$data = fgets($this->f,1024);
if (strlen(trim($data)) == 0)
$data = fgets($this->f, 1024);
if (preg_match("/trailer/",$data)) {
if (preg_match("/(.*trailer[ \n\r]*)/",$data,$m)) {
fseek($this->f, $o_pos+strlen($m[1]));
}
$c = new pdf_context($this->f);
$trailer = $this->pdf_read_value($c);
if (isset($trailer[1]['/Prev'])) {
$this->pdf_read_xref($result, $trailer[1]['/Prev'][1]);
$result['trailer'][1] = array_merge($result['trailer'][1], $trailer[1]);
} else {
$result['trailer'] = $trailer;
}
} else {
$data = explode(' ', trim($data));
if (count($data) != 2) {
fseek($this->f, $o_pos);
$data = explode(' ', trim (_fgets ($this->f, true)));
if (count($data) != 2) {
$this->error("Unexpected data in xref table");
}
}
$this->pdf_read_xref($result, null, (int) $data[0], (int) $data[0] + (int) $data[1]);
}
}
/**
* Reads an Value
*
* @param object $c pdf_context
* @param string $token a Token
* @return mixed
*/
function pdf_read_value(&$c, $token = null) {
if (is_null($token)) {
$token = $this->pdf_read_token($c);
}
if ($token === false) {
return false;
}
switch ($token) {
case '<':
// This is a hex string.
// Read the value, then the terminator
$pos = $c->offset;
while(1) {
$match = strpos ($c->buffer, '>', $pos);
// If you can't find it, try
// reading more data from the stream
if ($match === false) {
if (!$c->increase_length()) {
return false;
} else {
continue;
}
}
$result = substr ($c->buffer, $c->offset, $match - $c->offset);
$c->offset = $match+1;
return array (PDF_TYPE_HEX, $result);
}
break;
case '<<':
// This is a dictionary.
$result = array();
// Recurse into this function until we reach
// the end of the dictionary.
while (($key = $this->pdf_read_token($c)) !== '>>') {
if ($key === false) {
return false;
}
if (($value = $this->pdf_read_value($c)) === false) {
return false;
}
$result[$key] = $value;
}
return array (PDF_TYPE_DICTIONARY, $result);
case '[':
// This is an array.
$result = array();
// Recurse into this function until we reach
// the end of the array.
while (($token = $this->pdf_read_token($c)) !== ']') {
if ($token === false) {
return false;
}
if (($value = $this->pdf_read_value($c, $token)) === false) {
return false;
}
$result[] = $value;
}
return array (PDF_TYPE_ARRAY, $result);
case '(' :
// This is a string
$pos = $c->offset;
while(1) {
// Start by finding the next closed
// parenthesis
$match = strpos ($c->buffer, ')', $pos);
// If you can't find it, try
// reading more data from the stream
if ($match === false) {
if (!$c->increase_length()) {
return false;
} else {
continue;
}
}
// Make sure that there is no backslash
// before the parenthesis. If there is,
// move on. Otherwise, return the string.
$esc = preg_match('/([\\\\]+)$/', $tmpresult = substr($c->buffer, $c->offset, $match - $c->offset), $m);
if ($esc === 0 || strlen($m[1]) % 2 == 0) {
$result = $tmpresult;
$c->offset = $match + 1;
return array (PDF_TYPE_STRING, $result);
} else {
$pos = $match + 1;
if ($pos > $c->offset + $c->length) {
$c->increase_length();
}
}
}
case "stream":
$o_pos = ftell($c->file)-strlen($c->buffer);
$o_offset = $c->offset;
$c->reset($startpos = $o_pos + $o_offset);
$e = 0; // ensure line breaks in front of the stream
if ($c->buffer[0] == chr(10) || $c->buffer[0] == chr(13))
$e++;
if ($c->buffer[1] == chr(10) && $c->buffer[0] != chr(10))
$e++;
if ($this->actual_obj[1][1]['/Length'][0] == PDF_TYPE_OBJREF) {
$tmp_c = new pdf_context($this->f);
$tmp_length = $this->pdf_resolve_object($tmp_c,$this->actual_obj[1][1]['/Length']);
$length = $tmp_length[1][1];
} else {
$length = $this->actual_obj[1][1]['/Length'][1];
}
if ($length > 0) {
$c->reset($startpos+$e,$length);
$v = $c->buffer;
} else {
$v = '';
}
$c->reset($startpos+$e+$length+9); // 9 = strlen("endstream")
return array(PDF_TYPE_STREAM, $v);
default :
if (is_numeric ($token)) {
// A numeric token. Make sure that
// it is not part of something else.
if (($tok2 = $this->pdf_read_token ($c)) !== false) {
if (is_numeric ($tok2)) {
// Two numeric tokens in a row.
// In this case, we're probably in
// front of either an object reference
// or an object specification.
// Determine the case and return the data
if (($tok3 = $this->pdf_read_token ($c)) !== false) {
switch ($tok3) {
case 'obj' :
return array (PDF_TYPE_OBJDEC, (int) $token, (int) $tok2);
case 'R' :
return array (PDF_TYPE_OBJREF, (int) $token, (int) $tok2);
}
// If we get to this point, that numeric value up
// there was just a numeric value. Push the extra
// tokens back into the stack and return the value.
array_push ($c->stack, $tok3);
}
}
array_push ($c->stack, $tok2);
}
return array (PDF_TYPE_NUMERIC, $token);
} else {
// Just a token. Return it.
return array (PDF_TYPE_TOKEN, $token);
}
}
}
/**
* Resolve an object
*
* @param object $c pdf_context
* @param array $obj_spec The object-data
* @param boolean $encapsulate Must set to true, cause the parsing and fpdi use this method only without this para
*/
function pdf_resolve_object(&$c, $obj_spec, $encapsulate = true) {
// Exit if we get invalid data
if (!is_array($obj_spec)) {
return false;
}
if ($obj_spec[0] == PDF_TYPE_OBJREF) {
// This is a reference, resolve it
if (isset($this->xref['xref'][$obj_spec[1]][$obj_spec[2]])) {
// Save current file position
// This is needed if you want to resolve
// references while you're reading another object
// (e.g.: if you need to determine the length
// of a stream)
$old_pos = ftell($c->file);
// Reposition the file pointer and
// load the object header.
$c->reset($this->xref['xref'][$obj_spec[1]][$obj_spec[2]]);
$header = $this->pdf_read_value($c,null,true);
if ($header[0] != PDF_TYPE_OBJDEC || $header[1] != $obj_spec[1] || $header[2] != $obj_spec[2]) {
$this->error("Unable to find object ({$obj_spec[1]}, {$obj_spec[2]}) at expected location");
}
// If we're being asked to store all the information
// about the object, we add the object ID and generation
// number for later use
$this->actual_obj =& $result;
if ($encapsulate) {
$result = array (
PDF_TYPE_OBJECT,
'obj' => $obj_spec[1],
'gen' => $obj_spec[2]
);
} else {
$result = array();
}
// Now simply read the object data until
// we encounter an end-of-object marker
while(1) {
$value = $this->pdf_read_value($c);
if ($value === false || count($result) > 4) {
// in this case the parser coudn't find an endobj so we break here
break;
}
if ($value[0] == PDF_TYPE_TOKEN && $value[1] === 'endobj') {
break;
}
$result[] = $value;
}
$c->reset($old_pos);
if (isset($result[2][0]) && $result[2][0] == PDF_TYPE_STREAM) {
$result[0] = PDF_TYPE_STREAM;
}
return $result;
}
} else {
return $obj_spec;
}
}
/**
* Reads a token from the file
*
* @param object $c pdf_context
* @return mixed
*/
function pdf_read_token(&$c)
{
// If there is a token available
// on the stack, pop it out and
// return it.
if (count($c->stack)) {
return array_pop($c->stack);
}
// Strip away any whitespace
do {
if (!$c->ensure_content()) {
return false;
}
$c->offset += _strspn($c->buffer, " \n\r\t", $c->offset);
} while ($c->offset >= $c->length - 1);
// Get the first character in the stream
$char = $c->buffer[$c->offset++];
switch ($char) {
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;
}
}
}
?> |
