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PHP PDF convert to txt extract Content txt Example

kevinmel2000 profile image Teddy Zugana ・5 min read

class PDF2Text {
// Some settings
var $multibyte = 4; // Use setUnicode(TRUE|FALSE)
var $convertquotes = ENT_QUOTES; // ENT_COMPAT (double-quotes), ENT_QUOTES (Both), ENT_NOQUOTES (None)
var $showprogress = true; // TRUE if you have problems with time-out

// Variables
var $filename = '';
var $decodedtext = '';

function setFilename($filename) {
    // Reset
    $this->decodedtext = '';
    $this->filename = $filename;
}

function output($echo = false) {
    if($echo) echo $this->decodedtext;
    else return $this->decodedtext;
}

function setUnicode($input) {
    // 4 for unicode. But 2 should work in most cases just fine
    if($input == true) $this->multibyte = 4;
    else $this->multibyte = 2;
}

function decodePDF() {
    // Read the data from pdf file
    $infile = @file_get_contents($this->filename, FILE_BINARY);
    if (empty($infile))
        return "";

    // Get all text data.
    $transformations = array();
    $texts = array();

    // Get the list of all objects.
    preg_match_all("#obj[\n|\r](.*)endobj[\n|\r]#ismU", $infile . "endobj\r", $objects);
    $objects = @$objects[1];

    // Select objects with streams.
    for ($i = 0; $i < count($objects); $i++) {
        $currentObject = $objects[$i];

        // Prevent time-out
        @set_time_limit ();
        if($this->showprogress) {
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// echo ". ";
flush(); ob_flush();
}

        // Check if an object includes data stream.
        if (preg_match("#stream[\n|\r](.*)endstream[\n|\r]#ismU", $currentObject . "endstream\r", $stream )) {
            $stream = ltrim($stream[1]);
            // Check object parameters and look for text data.
            $options = $this->getObjectOptions($currentObject);

            if (!(empty($options["Length1"]) && empty($options["Type"]) && empty($options["Subtype"])) )
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// if ( $options["Image"] && $options["Subtype"] )
// if (!(empty($options["Length1"]) && empty($options["Subtype"])) )
continue;

            // Hack, length doesnt always seem to be correct
            unset($options["Length"]);

            // So, we have text data. Decode it.
            $data = $this->getDecodedStream($stream, $options);

            if (strlen($data)) {
                if (preg_match_all("#BT[\n|\r](.*)ET[\n|\r]#ismU", $data . "ET\r", $textContainers)) {
                    $textContainers = @$textContainers[1];
                    $this->getDirtyTexts($texts, $textContainers);
                } else
                    $this->getCharTransformations($transformations, $data);
            }
        }
    }

    // Analyze text blocks taking into account character transformations and return results.
    $this->decodedtext = $this->getTextUsingTransformations($texts, $transformations);
}


function decodeAsciiHex($input) {
    $output = "";

    $isOdd = true;
    $isComment = false;

    for($i = 0, $codeHigh = -1; $i < strlen($input) && $input[$i] != '>'; $i++) {
        $c = $input[$i];

        if($isComment) {
            if ($c == '\r' || $c == '\n')
                $isComment = false;
            continue;
        }

        switch($c) {
            case '\0': case '\t': case '\r': case '\f': case '\n': case ' ': break;
            case '%':
                $isComment = true;
            break;

            default:
                $code = hexdec($c);
                if($code === 0 && $c != '0')
                    return "";

                if($isOdd)
                    $codeHigh = $code;
                else
                    $output .= chr($codeHigh * 16 + $code);

                $isOdd = !$isOdd;
            break;
        }
    }

    if($input[$i] != '>')
        return "";

    if($isOdd)
        $output .= chr($codeHigh * 16);

    return $output;
}

function decodeAscii85($input) {
    $output = "";

    $isComment = false;
    $ords = array();

    for($i = 0, $state = 0; $i < strlen($input) && $input[$i] != '~'; $i++) {
        $c = $input[$i];

        if($isComment) {
            if ($c == '\r' || $c == '\n')
                $isComment = false;
            continue;
        }

        if ($c == '\0' || $c == '\t' || $c == '\r' || $c == '\f' || $c == '\n' || $c == ' ')
            continue;
        if ($c == '%') {
            $isComment = true;
            continue;
        }
        if ($c == 'z' && $state === 0) {
            $output .= str_repeat(chr(0), 4);
            continue;
        }
        if ($c < '!' || $c > 'u')
            return "";

        $code = ord($input[$i]) & 0xff;
        $ords[$state++] = $code - ord('!');

        if ($state == 5) {
            $state = 0;
            for ($sum = 0, $j = 0; $j < 5; $j++)
                $sum = $sum * 85 + $ords[$j];
            for ($j = 3; $j >= 0; $j--)
                $output .= chr($sum >> ($j * 8));
        }
    }
    if ($state === 1)
        return "";
    elseif ($state > 1) {
        for ($i = 0, $sum = 0; $i < $state; $i++)
            $sum += ($ords[$i] + ($i == $state - 1)) * pow(85, 4 - $i);
        for ($i = 0; $i < $state - 1; $i++) {
            try {
                if(false == ($o = chr($sum >> ((3 - $i) * 8)))) {
                    throw new Exception('Error');
                }
                $output .= $o;
            } catch (Exception $e) { /*Dont do anything*/ }
        }
    }

    return $output;
}

function decodeFlate($data) {
    return @gzuncompress($data);
}

function getObjectOptions($object) {
    $options = array();

    if (preg_match("#<<(.*)>>#ismU", $object, $options)) {
        $options = explode("/", $options[1]);
        @array_shift($options);

        $o = array();
        for ($j = 0; $j < @count($options); $j++) {
            $options[$j] = preg_replace("#\s+#", " ", trim($options[$j]));
            if (strpos($options[$j], " ") !== false) {
                $parts = explode(" ", $options[$j]);
                $o[$parts[0]] = $parts[1];
            } else
                $o[$options[$j]] = true;
        }
        $options = $o;
        unset($o);
    }

    return $options;
}

function getDecodedStream($stream, $options) {
    $data = "";
    if (empty($options["Filter"]))
        $data = $stream;
    else {
        $length = !empty($options["Length"]) ? $options["Length"] : strlen($stream);
        $_stream = substr($stream, 0, $length);

        foreach ($options as $key => $value) {
            if ($key == "ASCIIHexDecode")
                $_stream = $this->decodeAsciiHex($_stream);
            elseif ($key == "ASCII85Decode")
                $_stream = $this->decodeAscii85($_stream);
            elseif ($key == "FlateDecode")
                $_stream = $this->decodeFlate($_stream);
            elseif ($key == "Crypt") { // TO DO
            }
        }
        $data = $_stream;
    }
    return $data;
}

function getDirtyTexts(&$texts, $textContainers) {
    for ($j = 0; $j < count($textContainers); $j++) {
        if (preg_match_all("#\[(.*)\]\s*TJ[\n|\r]#ismU", $textContainers[$j], $parts))
            $texts = array_merge($texts, array(@implode('', $parts[1])));
        elseif (preg_match_all("#T[d|w|m|f]\s*(\(.*\))\s*Tj[\n|\r]#ismU", $textContainers[$j], $parts))
            $texts = array_merge($texts, array(@implode('', $parts[1])));
        elseif (preg_match_all("#T[d|w|m|f]\s*(\[.*\])\s*Tj[\n|\r]#ismU", $textContainers[$j], $parts))
            $texts = array_merge($texts, array(@implode('', $parts[1])));
    }

}

function getCharTransformations(&$transformations, $stream) {
    preg_match_all("#([0-9]+)\s+beginbfchar(.*)endbfchar#ismU", $stream, $chars, PREG_SET_ORDER);
    preg_match_all("#([0-9]+)\s+beginbfrange(.*)endbfrange#ismU", $stream, $ranges, PREG_SET_ORDER);

    for ($j = 0; $j < count($chars); $j++) {
        $count = $chars[$j][1];
        $current = explode("\n", trim($chars[$j][2]));
        for ($k = 0; $k < $count && $k < count($current); $k++) {
            if (preg_match("#<([0-9a-f]{2,4})>\s+<([0-9a-f]{4,512})>#is", trim($current[$k]), $map))
                $transformations[str_pad($map[1], 4, "0")] = $map[2];
        }
    }
    for ($j = 0; $j < count($ranges); $j++) {
        $count = $ranges[$j][1];
        $current = explode("\n", trim($ranges[$j][2]));
        for ($k = 0; $k < $count && $k < count($current); $k++) {
            if (preg_match("#<([0-9a-f]{4})>\s+<([0-9a-f]{4})>\s+<([0-9a-f]{4})>#is", trim($current[$k]), $map)) {
                $from = hexdec($map[1]);
                $to = hexdec($map[2]);
                $_from = hexdec($map[3]);

                for ($m = $from, $n = 0; $m <= $to; $m++, $n++)
                    $transformations[sprintf("%04X", $m)] = sprintf("%04X", $_from + $n);
            } elseif (preg_match("#<([0-9a-f]{4})>\s+<([0-9a-f]{4})>\s+\[(.*)\]#ismU", trim($current[$k]), $map)) {
                $from = hexdec($map[1]);
                $to = hexdec($map[2]);
                $parts = preg_split("#\s+#", trim($map[3]));

                for ($m = $from, $n = 0; $m <= $to && $n < count($parts); $m++, $n++)
                    $transformations[sprintf("%04X", $m)] = sprintf("%04X", hexdec($parts[$n]));
            }
        }
    }
}
function getTextUsingTransformations($texts, $transformations) {
    $document = "";
    for ($i = 0; $i < count($texts); $i++) {
        $isHex = false;
        $isPlain = false;

        $hex = "";
        $plain = "";
        for ($j = 0; $j < strlen($texts[$i]); $j++) {
            $c = $texts[$i][$j];
            switch($c) {
                case "<":
                    $hex = "";
                    $isHex = true;
                    $isPlain = false;
                break;
                case ">":
                    $hexs = str_split($hex, $this->multibyte); // 2 or 4 (UTF8 or ISO)
                    for ($k = 0; $k < count($hexs); $k++) {

                        $chex = str_pad($hexs[$k], 4, "0"); // Add tailing zero
                        if (isset($transformations[$chex]))
                            $chex = $transformations[$chex];
                        $document .= html_entity_decode("&#x".$chex.";");
                    }
                    $isHex = false;
                break;
                case "(":
                    $plain = "";
                    $isPlain = true;
                    $isHex = false;
                break;
                case ")":
                    $document .= $plain;
                    $isPlain = false;
                break;
                case "\\":
                    $c2 = $texts[$i][$j + 1];
                    if (in_array($c2, array("\\", "(", ")"))) $plain .= $c2;
                    elseif ($c2 == "n") $plain .= '\n';
                    elseif ($c2 == "r") $plain .= '\r';
                    elseif ($c2 == "t") $plain .= '\t';
                    elseif ($c2 == "b") $plain .= '\b';
                    elseif ($c2 == "f") $plain .= '\f';
                    elseif ($c2 >= '0' && $c2 <= '9') {
                        $oct = preg_replace("#[^0-9]#", "", substr($texts[$i], $j + 1, 3));
                        $j += strlen($oct) - 1;
                        $plain .= html_entity_decode("&#".octdec($oct).";", $this->convertquotes);
                    }
                    $j++;
                break;

                default:
                    if ($isHex)
                        $hex .= $c;
                    elseif ($isPlain)
                        $plain .= $c;
                break;
            }
        }
        $document .= "\n";
    }

    return $document;
}
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}

example call :

$a = new PDF2Text();
$a->setFilename($input_file);
$a->decodePDF();
$txt = $a->output();

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