I want to read and write the xmp metadata packet inside an adobe pdf
file. I can successfully read out the packets with a grep pattern, but
writing it back is much more complex. I have an idea of how it is
done, but I'm wondering if anybody has done this. How can I use php to
write a new xmp metadata packet into an adobe pdf file without
corrupting the file?

---

Clarification of Question by phoogoo-ga on 25 Sep 2004 18:24 PDT

This is specifically about writing an xmp metadata packet inside an
adobe pdf file. It seems to involve udating the "dictionary" (?) or
something and whatever other requirements to prevent the file from
becoming corrupted.

int fwrite (int fp, string string [, int length])
 
fwrite() writes the contents of string to the file stream pointed to
by fp. If the length argument is given, writing will stop after length
bytes have been written or the end of string is reached, whichever
comes first.

Purpose: Binary-safe file read 
Usage: string fread (int fp, int length) 
Availability: PHP 3, PHP 4 >= 4.0.0 

fread() reads up to length bytes from the file pointer referenced by
fp. Reading stops when length bytes have been read or EOF is reached,
whichever comes first.

// get contents of a file into a string
$filename = "/usr/local/something.txt";
$fd = fopen ($filename, "r");
$contents = fread ($fd, filesize ($filename));
fclose ($fd);

/* binary file read & write */
// for binary file read and write we have to use the mode 'b' b for binary
//in php to open a binary file use

$filename="xyz.pdf";
$fp=fopen($filename,"rb");
$contents=fread($fp,filesize($filename));
fclose($fp);

/* in the contents u can modify what xmp u want */

again 
$filename="xyz.pdf";
$fp=fopen($filename,"wb");
if (fwrite($fp, $contents) === FALSE)
{
        echo "Cannot write to file ($filename)";
        exit;
}
fclose($fp);


try with this method

regards

indianguysiva-ga