<?php
namespace splitbrain\PHPArchive;
/**
* Class Zip
*
* Creates or extracts Zip archives
*
* for specs see http://www.pkware.com/appnote
*
* @author Andreas Gohr <andi@splitbrain.org>
* @package splitbrain\PHPArchive
* @license MIT
*/
class Zip extends Archive
{
const LOCAL_FILE_HEADER_CRC_OFFSET = 14;
protected $file = '';
protected $fh;
protected $memory = '';
protected $closed = true;
protected $writeaccess = false;
protected $ctrl_dir;
protected $complevel = 9;
/**
* Set the compression level.
*
* Compression Type is ignored for ZIP
*
* You can call this function before adding each file to set differen compression levels
* for each file.
*
* @param int $level Compression level (0 to 9)
* @param int $type Type of compression to use ignored for ZIP
* @throws ArchiveIllegalCompressionException
*/
public function setCompression($level = 9, $type = Archive::COMPRESS_AUTO)
{
if ($level < -1 || $level > 9) {
throw new ArchiveIllegalCompressionException('Compression level should be between -1 and 9');
}
$this->complevel = $level;
}
/**
* Open an existing ZIP file for reading
*
* @param string $file
* @throws ArchiveIOException
*/
public function open($file)
{
$this->file = $file;
$this->fh = @fopen($this->file, 'rb');
if (!$this->fh) {
throw new ArchiveIOException('Could not open file for reading: '.$this->file);
}
$this->closed = false;
}
/**
* Read the contents of a ZIP archive
*
* This function lists the files stored in the archive, and returns an indexed array of FileInfo objects
*
* The archive is closed afer reading the contents, for API compatibility with TAR files
* Reopen the file with open() again if you want to do additional operations
*
* @throws ArchiveIOException
* @return FileInfo[]
*/
public function contents()
{
$result = array();
foreach ($this->yieldContents() as $fileinfo) {
$result[] = $fileinfo;
}
return $result;
}
/**
* Read the contents of a ZIP archive and return each entry using yield
* for memory efficiency.
*
* @see contents()
* @throws ArchiveIOException
* @return FileInfo[]
*/
public function yieldContents()
{
if ($this->closed || !$this->file) {
throw new ArchiveIOException('Can not read from a closed archive');
}
$centd = $this->readCentralDir();
@rewind($this->fh);
@fseek($this->fh, $centd['offset']);
for ($i = 0; $i < $centd['entries']; $i++) {
yield $this->header2fileinfo($this->readCentralFileHeader());
}
$this->close();
}
/**
* Extract an existing ZIP archive
*
* The $strip parameter allows you to strip a certain number of path components from the filenames
* found in the tar file, similar to the --strip-components feature of GNU tar. This is triggered when
* an integer is passed as $strip.
* Alternatively a fixed string prefix may be passed in $strip. If the filename matches this prefix,
* the prefix will be stripped. It is recommended to give prefixes with a trailing slash.
*
* By default this will extract all files found in the archive. You can restrict the output using the $include
* and $exclude parameter. Both expect a full regular expression (including delimiters and modifiers). If
* $include is set only files that match this expression will be extracted. Files that match the $exclude
* expression will never be extracted. Both parameters can be used in combination. Expressions are matched against
* stripped filenames as described above.
*
* @param string $outdir the target directory for extracting
* @param int|string $strip either the number of path components or a fixed prefix to strip
* @param string $exclude a regular expression of files to exclude
* @param string $include a regular expression of files to include
* @throws ArchiveIOException
* @return FileInfo[]
*/
public function extract($outdir, $strip = '', $exclude = '', $include = '')
{
if ($this->closed || !$this->file) {
throw new ArchiveIOException('Can not read from a closed archive');
}
$outdir = rtrim($outdir, '/');
@mkdir($outdir, 0777, true);
$extracted = array();
$cdir = $this->readCentralDir();
$pos_entry = $cdir['offset']; // begin of the central file directory
for ($i = 0; $i < $cdir['entries']; $i++) {
// read file header
@fseek($this->fh, $pos_entry);
$header = $this->readCentralFileHeader();
$header['index'] = $i;
$pos_entry = ftell($this->fh); // position of the next file in central file directory
fseek($this->fh, $header['offset']); // seek to beginning of file header
$header = $this->readFileHeader($header);
$fileinfo = $this->header2fileinfo($header);
// apply strip rules
$fileinfo->strip($strip);
// skip unwanted files
if (!strlen($fileinfo->getPath()) || !$fileinfo->matchExpression($include, $exclude)) {
continue;
}
$extracted[] = $fileinfo;
// create output directory
$output = $outdir.'/'.$fileinfo->getPath();
$directory = ($header['folder']) ? $output : dirname($output);
@mkdir($directory, 0777, true);
// nothing more to do for directories
if ($fileinfo->getIsdir()) {
if(is_callable($this->callback)) {
call_user_func($this->callback, $fileinfo);
}
continue;
}
// compressed files are written to temporary .gz file first
if ($header['compression'] == 0) {
$extractto = $output;
} else {
$extractto = $output.'.gz';
}
// open file for writing
$fp = @fopen($extractto, "wb");
if (!$fp) {
throw new ArchiveIOException('Could not open file for writing: '.$extractto);
}
// prepend compression header
if ($header['compression'] != 0) {
$binary_data = pack(
'va1a1Va1a1',
0x8b1f,
chr($header['compression']),
chr(0x00),
time(),
chr(0x00),
chr(3)
);
fwrite($fp, $binary_data, 10);
}
// read the file and store it on disk
$size = $header['compressed_size'];
while ($size != 0) {
$read_size = ($size < 2048 ? $size : 2048);
$buffer = fread($this->fh, $read_size);
$binary_data = pack('a'.$read_size, $buffer);
fwrite($fp, $binary_data, $read_size);
$size -= $read_size;
}
// finalize compressed file
if ($header['compression'] != 0) {
$binary_data = pack('VV', $header['crc'], $header['size']);
fwrite($fp, $binary_data, 8);
}
// close file
fclose($fp);
// unpack compressed file
if ($header['compression'] != 0) {
$gzp = @gzopen($extractto, 'rb');
if (!$gzp) {
@unlink($extractto);
throw new ArchiveIOException('Failed file extracting. gzip support missing?');
}
$fp = @fopen($output, 'wb');
if (!$fp) {
throw new ArchiveIOException('Could not open file for writing: '.$extractto);
}
$size = $header['size'];
while ($size != 0) {
$read_size = ($size < 2048 ? $size : 2048);
$buffer = gzread($gzp, $read_size);
$binary_data = pack('a'.$read_size, $buffer);
@fwrite($fp, $binary_data, $read_size);
$size -= $read_size;
}
fclose($fp);
gzclose($gzp);
unlink($extractto); // remove temporary gz file
}
@touch($output, $fileinfo->getMtime());
//FIXME what about permissions?
if(is_callable($this->callback)) {
call_user_func($this->callback, $fileinfo);
}
}
$this->close();
return $extracted;
}
/**
* Create a new ZIP file
*
* If $file is empty, the zip file will be created in memory
*
* @param string $file
* @throws ArchiveIOException
*/
public function create($file = '')
{
$this->file = $file;
$this->memory = '';
$this->fh = 0;
if ($this->file) {
$this->fh = @fopen($this->file, 'wb');
if (!$this->fh) {
throw new ArchiveIOException('Could not open file for writing: '.$this->file);
}
}
$this->writeaccess = true;
$this->closed = false;
$this->ctrl_dir = array();
}
/**
* Add a file to the current ZIP archive using an existing file in the filesystem
*
* @param string $file path to the original file
* @param string|FileInfo $fileinfo either the name to us in archive (string) or a FileInfo oject with all meta data, empty to take from original
* @throws ArchiveIOException
*/
/**
* Add a file to the current archive using an existing file in the filesystem
*
* @param string $file path to the original file
* @param string|FileInfo $fileinfo either the name to use in archive (string) or a FileInfo oject with all meta data, empty to take from original
* @throws ArchiveIOException
* @throws FileInfoException
*/
public function addFile($file, $fileinfo = '')
{
if (is_string($fileinfo)) {
$fileinfo = FileInfo::fromPath($file, $fileinfo);
}
if ($this->closed) {
throw new ArchiveIOException('Archive has been closed, files can no longer be added');
}
$fp = @fopen($file, 'rb');
if ($fp === false) {
throw new ArchiveIOException('Could not open file for reading: '.$file);
}
$offset = $this->dataOffset();
$name = $fileinfo->getPath();
$time = $fileinfo->getMtime();
// write local file header (temporary CRC and size)
$this->writebytes($this->makeLocalFileHeader(
$time,
0,
0,
0,
$name,
(bool) $this->complevel
));
// we store no encryption header
// prepare info, compress and write data to archive
$deflate_context = deflate_init(ZLIB_ENCODING_DEFLATE, ['level' => $this->complevel]);
$crc_context = hash_init('crc32b');
$size = $csize = 0;
while (!feof($fp)) {
$block = fread($fp, 512);
if ($this->complevel) {
$is_first_block = $size === 0;
$is_last_block = feof($fp);
if ($is_last_block) {
$c_block = deflate_add($deflate_context, $block, ZLIB_FINISH);
// get rid of the compression footer
$c_block = substr($c_block, 0, -4);
} else {
$c_block = deflate_add($deflate_context, $block, ZLIB_NO_FLUSH);
}
// get rid of the compression header
if ($is_first_block) {
$c_block = substr($c_block, 2);
}
$csize += strlen($c_block);
$this->writebytes($c_block);
} else {
$this->writebytes($block);
}
$size += strlen($block);
hash_update($crc_context, $block);
}
fclose($fp);
// update the local file header with the computed CRC and size
$crc = hexdec(hash_final($crc_context));
$csize = $this->complevel ? $csize : $size;
$this->writebytesAt($this->makeCrcAndSize(
$crc,
$size,
$csize
), $offset + self::LOCAL_FILE_HEADER_CRC_OFFSET);
// we store no data descriptor
// add info to central file directory
$this->ctrl_dir[] = $this->makeCentralFileRecord(
$offset,
$time,
$crc,
$size,
$csize,
$name,
(bool) $this->complevel
);
if(is_callable($this->callback)) {
call_user_func($this->callback, $fileinfo);
}
}
/**
* Add a file to the current Zip archive using the given $data as content
*
* @param string|FileInfo $fileinfo either the name to us in archive (string) or a FileInfo oject with all meta data
* @param string $data binary content of the file to add
* @throws ArchiveIOException
*/
public function addData($fileinfo, $data)
{
if (is_string($fileinfo)) {
$fileinfo = new FileInfo($fileinfo);
}
if ($this->closed) {
throw new ArchiveIOException('Archive has been closed, files can no longer be added');
}
// prepare info and compress data
$size = strlen($data);
$crc = crc32($data);
if ($this->complevel) {
$data = gzcompress($data, $this->complevel);
$data = substr($data, 2, -4); // strip compression headers
}
$csize = strlen($data);
$offset = $this->dataOffset();
$name = $fileinfo->getPath();
$time = $fileinfo->getMtime();
// write local file header
$this->writebytes($this->makeLocalFileHeader(
$time,
$crc,
$size,
$csize,
$name,
(bool) $this->complevel
));
// we store no encryption header
// write data
$this->writebytes($data);
// we store no data descriptor
// add info to central file directory
$this->ctrl_dir[] = $this->makeCentralFileRecord(
$offset,
$time,
$crc,
$size,
$csize,
$name,
(bool) $this->complevel
);
if(is_callable($this->callback)) {
call_user_func($this->callback, $fileinfo);
}
}
/**
* Add the closing footer to the archive if in write mode, close all file handles
*
* After a call to this function no more data can be added to the archive, for
* read access no reading is allowed anymore
* @throws ArchiveIOException
*/
public function close()
{
if ($this->closed) {
return;
} // we did this already
if ($this->writeaccess) {
// write central directory
$offset = $this->dataOffset();
$ctrldir = join('', $this->ctrl_dir);
$this->writebytes($ctrldir);
// write end of central directory record
$this->writebytes("\x50\x4b\x05\x06"); // end of central dir signature
$this->writebytes(pack('v', 0)); // number of this disk
$this->writebytes(pack('v', 0)); // number of the disk with the start of the central directory
$this->writebytes(pack('v',
count($this->ctrl_dir))); // total number of entries in the central directory on this disk
$this->writebytes(pack('v', count($this->ctrl_dir))); // total number of entries in the central directory
$this->writebytes(pack('V', strlen($ctrldir))); // size of the central directory
$this->writebytes(pack('V',
$offset)); // offset of start of central directory with respect to the starting disk number
$this->writebytes(pack('v', 0)); // .ZIP file comment length
$this->ctrl_dir = array();
}
// close file handles
if ($this->file) {
fclose($this->fh);
$this->file = '';
$this->fh = 0;
}
$this->writeaccess = false;
$this->closed = true;
}
/**
* Returns the created in-memory archive data
*
* This implicitly calls close() on the Archive
* @throws ArchiveIOException
*/
public function getArchive()
{
$this->close();
return $this->memory;
}
/**
* Save the created in-memory archive data
*
* Note: It's more memory effective to specify the filename in the create() function and
* let the library work on the new file directly.
*
* @param $file
* @throws ArchiveIOException
*/
public function save($file)
{
if (!@file_put_contents($file, $this->getArchive())) {
throw new ArchiveIOException('Could not write to file: '.$file);
}
}
/**
* Read the central directory
*
* This key-value list contains general information about the ZIP file
*
* @return array
*/
protected function readCentralDir()
{
$size = filesize($this->file);
if ($size < 277) {
$maximum_size = $size;
} else {
$maximum_size = 277;
}
@fseek($this->fh, $size - $maximum_size);
$pos = ftell($this->fh);
$bytes = 0x00000000;
while ($pos < $size) {
$byte = @fread($this->fh, 1);
$bytes = (($bytes << 8) & 0xFFFFFFFF) | ord($byte);
if ($bytes == 0x504b0506) {
break;
}
$pos++;
}
$data = unpack(
'vdisk/vdisk_start/vdisk_entries/ventries/Vsize/Voffset/vcomment_size',
fread($this->fh, 18)
);
if ($data['comment_size'] != 0) {
$centd['comment'] = fread($this->fh, $data['comment_size']);
} else {
$centd['comment'] = '';
}
$centd['entries'] = $data['entries'];
$centd['disk_entries'] = $data['disk_entries'];
$centd['offset'] = $data['offset'];
$centd['disk_start'] = $data['disk_start'];
$centd['size'] = $data['size'];
$centd['disk'] = $data['disk'];
return $centd;
}
/**
* Read the next central file header
*
* Assumes the current file pointer is pointing at the right position
*
* @return array
*/
protected function readCentralFileHeader()
{
$binary_data = fread($this->fh, 46);
$header = unpack(
'vchkid/vid/vversion/vversion_extracted/vflag/vcompression/vmtime/vmdate/Vcrc/Vcompressed_size/Vsize/vfilename_len/vextra_len/vcomment_len/vdisk/vinternal/Vexternal/Voffset',
$binary_data
);
if ($header['filename_len'] != 0) {
$header['filename'] = fread($this->fh, $header['filename_len']);
} else {
$header['filename'] = '';
}
if ($header['extra_len'] != 0) {
$header['extra'] = fread($this->fh, $header['extra_len']);
$header['extradata'] = $this->parseExtra($header['extra']);
} else {
$header['extra'] = '';
$header['extradata'] = array();
}
if ($header['comment_len'] != 0) {
$header['comment'] = fread($this->fh, $header['comment_len']);
} else {
$header['comment'] = '';
}
$header['mtime'] = $this->makeUnixTime($header['mdate'], $header['mtime']);
$header['stored_filename'] = $header['filename'];
$header['status'] = 'ok';
if (substr($header['filename'], -1) == '/') {
$header['external'] = 0x41FF0010;
}
$header['folder'] = ($header['external'] == 0x41FF0010 || $header['external'] == 16) ? 1 : 0;
return $header;
}
/**
* Reads the local file header
*
* This header precedes each individual file inside the zip file. Assumes the current file pointer is pointing at
* the right position already. Enhances the given central header with the data found at the local header.
*
* @param array $header the central file header read previously (see above)
* @return array
*/
protected function readFileHeader($header)
{
$binary_data = fread($this->fh, 30);
$data = unpack(
'vchk/vid/vversion/vflag/vcompression/vmtime/vmdate/Vcrc/Vcompressed_size/Vsize/vfilename_len/vextra_len',
$binary_data
);
$header['filename'] = fread($this->fh, $data['filename_len']);
if ($data['extra_len'] != 0) {
$header['extra'] = fread($this->fh, $data['extra_len']);
$header['extradata'] = array_merge($header['extradata'], $this->parseExtra($header['extra']));
} else {
$header['extra'] = '';
$header['extradata'] = array();
}
$header['compression'] = $data['compression'];
foreach (array(
'size',
'compressed_size',
'crc'
) as $hd) { // On ODT files, these headers are 0. Keep the previous value.
if ($data[$hd] != 0) {
$header[$hd] = $data[$hd];
}
}
$header['flag'] = $data['flag'];
$header['mtime'] = $this->makeUnixTime($data['mdate'], $data['mtime']);
$header['stored_filename'] = $header['filename'];
$header['status'] = "ok";
$header['folder'] = ($header['external'] == 0x41FF0010 || $header['external'] == 16) ? 1 : 0;
return $header;
}
/**
* Parse the extra headers into fields
*
* @param string $header
* @return array
*/
protected function parseExtra($header)
{
$extra = array();
// parse all extra fields as raw values
while (strlen($header) !== 0) {
$set = unpack('vid/vlen', $header);
$header = substr($header, 4);
$value = substr($header, 0, $set['len']);
$header = substr($header, $set['len']);
$extra[$set['id']] = $value;
}
// handle known ones
if(isset($extra[0x6375])) {
$extra['utf8comment'] = substr($extra[0x7075], 5); // strip version and crc
}
if(isset($extra[0x7075])) {
$extra['utf8path'] = substr($extra[0x7075], 5); // strip version and crc
}
return $extra;
}
/**
* Create fileinfo object from header data
*
* @param $header
* @return FileInfo
*/
protected function header2fileinfo($header)
{
$fileinfo = new FileInfo();
$fileinfo->setSize($header['size']);
$fileinfo->setCompressedSize($header['compressed_size']);
$fileinfo->setMtime($header['mtime']);
$fileinfo->setComment($header['comment']);
$fileinfo->setIsdir($header['external'] == 0x41FF0010 || $header['external'] == 16);
if(isset($header['extradata']['utf8path'])) {
$fileinfo->setPath($header['extradata']['utf8path']);
} else {
$fileinfo->setPath($this->cpToUtf8($header['filename']));
}
if(isset($header['extradata']['utf8comment'])) {
$fileinfo->setComment($header['extradata']['utf8comment']);
} else {
$fileinfo->setComment($this->cpToUtf8($header['comment']));
}
return $fileinfo;
}
/**
* Convert the given CP437 encoded string to UTF-8
*
* Tries iconv with the correct encoding first, falls back to mbstring with CP850 which is
* similar enough. CP437 seems not to be available in mbstring. Lastly falls back to keeping the
* string as is, which is still better than nothing.
*
* On some systems iconv is available, but the codepage is not. We also check for that.
*
* @param $string
* @return string
*/
protected function cpToUtf8($string)
{
if (function_exists('iconv') && @iconv_strlen('', 'CP437') !== false) {
return iconv('CP437', 'UTF-8', $string);
} elseif (function_exists('mb_convert_encoding')) {
return mb_convert_encoding($string, 'UTF-8', 'CP850');
} else {
return $string;
}
}
/**
* Convert the given UTF-8 encoded string to CP437
*
* Same caveats as for cpToUtf8() apply
*
* @param $string
* @return string
*/
protected function utf8ToCp($string)
{
// try iconv first
if (function_exists('iconv')) {
$conv = @iconv('UTF-8', 'CP437//IGNORE', $string);
if($conv) return $conv; // it worked
}
// still here? iconv failed to convert the string. Try another method
// see http://php.net/manual/en/function.iconv.php#108643
if (function_exists('mb_convert_encoding')) {
return mb_convert_encoding($string, 'CP850', 'UTF-8');
} else {
return $string;
}
}
/**
* Write to the open filepointer or memory
*
* @param string $data
* @throws ArchiveIOException
* @return int number of bytes written
*/
protected function writebytes($data)
{
if (!$this->file) {
$this->memory .= $data;
$written = strlen($data);
} else {
$written = @fwrite($this->fh, $data);
}
if ($written === false) {
throw new ArchiveIOException('Failed to write to archive stream');
}
return $written;
}
/**
* Write to the open filepointer or memory at the specified offset
*
* @param string $data
* @param int $offset
* @throws ArchiveIOException
* @return int number of bytes written
*/
protected function writebytesAt($data, $offset) {
if (!$this->file) {
$this->memory .= substr_replace($this->memory, $data, $offset);
$written = strlen($data);
} else {
@fseek($this->fh, $offset);
$written = @fwrite($this->fh, $data);
@fseek($this->fh, 0, SEEK_END);
}
if ($written === false) {
throw new ArchiveIOException('Failed to write to archive stream');
}
return $written;
}
/**
* Current data pointer position
*
* @fixme might need a -1
* @return int
*/
protected function dataOffset()
{
if ($this->file) {
return ftell($this->fh);
} else {
return strlen($this->memory);
}
}
/**
* Create a DOS timestamp from a UNIX timestamp
*
* DOS timestamps start at 1980-01-01, earlier UNIX stamps will be set to this date
*
* @param $time
* @return int
*/
protected function makeDosTime($time)
{
$timearray = getdate($time);
if ($timearray['year'] < 1980) {
$timearray['year'] = 1980;
$timearray['mon'] = 1;
$timearray['mday'] = 1;
$timearray['hours'] = 0;
$timearray['minutes'] = 0;
$timearray['seconds'] = 0;
}
return (($timearray['year'] - 1980) << 25) |
($timearray['mon'] << 21) |
($timearray['mday'] << 16) |
($timearray['hours'] << 11) |
($timearray['minutes'] << 5) |
($timearray['seconds'] >> 1);
}
/**
* Create a UNIX timestamp from a DOS timestamp
*
* @param $mdate
* @param $mtime
* @return int
*/
protected function makeUnixTime($mdate = null, $mtime = null)
{
if ($mdate && $mtime) {
$year = (($mdate & 0xFE00) >> 9) + 1980;
$month = ($mdate & 0x01E0) >> 5;
$day = $mdate & 0x001F;
$hour = ($mtime & 0xF800) >> 11;
$minute = ($mtime & 0x07E0) >> 5;
$seconde = ($mtime & 0x001F) << 1;
$mtime = mktime($hour, $minute, $seconde, $month, $day, $year);
} else {
$mtime = time();
}
return $mtime;
}
/**
* Returns a local file header for the given data
*
* @param int $offset location of the local header
* @param int $ts unix timestamp
* @param int $crc CRC32 checksum of the uncompressed data
* @param int $len length of the uncompressed data
* @param int $clen length of the compressed data
* @param string $name file name
* @param boolean|null $comp if compression is used, if null it's determined from $len != $clen
* @return string
*/
protected function makeCentralFileRecord($offset, $ts, $crc, $len, $clen, $name, $comp = null)
{
if(is_null($comp)) $comp = $len != $clen;
$comp = $comp ? 8 : 0;
$dtime = dechex($this->makeDosTime($ts));
list($name, $extra) = $this->encodeFilename($name);
$header = "\x50\x4b\x01\x02"; // central file header signature
$header .= pack('v', 14); // version made by - VFAT
$header .= pack('v', 20); // version needed to extract - 2.0
$header .= pack('v', 0); // general purpose flag - no flags set
$header .= pack('v', $comp); // compression method - deflate|none
$header .= pack(
'H*',
$dtime[6] . $dtime[7] .
$dtime[4] . $dtime[5] .
$dtime[2] . $dtime[3] .
$dtime[0] . $dtime[1]
); // last mod file time and date
$header .= pack('V', $crc); // crc-32
$header .= pack('V', $clen); // compressed size
$header .= pack('V', $len); // uncompressed size
$header .= pack('v', strlen($name)); // file name length
$header .= pack('v', strlen($extra)); // extra field length
$header .= pack('v', 0); // file comment length
$header .= pack('v', 0); // disk number start
$header .= pack('v', 0); // internal file attributes
$header .= pack('V', 0); // external file attributes @todo was 0x32!?
$header .= pack('V', $offset); // relative offset of local header
$header .= $name; // file name
$header .= $extra; // extra (utf-8 filename)
return $header;
}
/**
* Returns a local file header for the given data
*
* @param int $ts unix timestamp
* @param int $crc CRC32 checksum of the uncompressed data
* @param int $len length of the uncompressed data
* @param int $clen length of the compressed data
* @param string $name file name
* @param boolean|null $comp if compression is used, if null it's determined from $len != $clen
* @return string
*/
protected function makeLocalFileHeader($ts, $crc, $len, $clen, $name, $comp = null)
{
if(is_null($comp)) $comp = $len != $clen;
$comp = $comp ? 8 : 0;
$dtime = dechex($this->makeDosTime($ts));
list($name, $extra) = $this->encodeFilename($name);
$header = "\x50\x4b\x03\x04"; // local file header signature
$header .= pack('v', 20); // version needed to extract - 2.0
$header .= pack('v', 0); // general purpose flag - no flags set
$header .= pack('v', $comp); // compression method - deflate|none
$header .= pack(
'H*',
$dtime[6] . $dtime[7] .
$dtime[4] . $dtime[5] .
$dtime[2] . $dtime[3] .
$dtime[0] . $dtime[1]
); // last mod file time and date
$header .= pack('V', $crc); // crc-32
$header .= pack('V', $clen); // compressed size
$header .= pack('V', $len); // uncompressed size
$header .= pack('v', strlen($name)); // file name length
$header .= pack('v', strlen($extra)); // extra field length
$header .= $name; // file name
$header .= $extra; // extra (utf-8 filename)
return $header;
}
/**
* Returns only a part of the local file header containing the CRC, size and compressed size.
* Used to update these fields for an already written header.
*
* @param int $crc CRC32 checksum of the uncompressed data
* @param int $len length of the uncompressed data
* @param int $clen length of the compressed data
* @return string
*/
protected function makeCrcAndSize($crc, $len, $clen) {
$header = pack('V', $crc); // crc-32
$header .= pack('V', $clen); // compressed size
$header .= pack('V', $len); // uncompressed size
return $header;
}
/**
* Returns an allowed filename and an extra field header
*
* When encoding stuff outside the 7bit ASCII range it needs to be placed in a separate
* extra field
*
* @param $original
* @return array($filename, $extra)
*/
protected function encodeFilename($original)
{
$cp437 = $this->utf8ToCp($original);
if ($cp437 === $original) {
return array($original, '');
}
$extra = pack(
'vvCV',
0x7075, // tag
strlen($original) + 5, // length of file + version + crc
1, // version
crc32($original) // crc
);
$extra .= $original;
return array($cp437, $extra);
}
}