php - Extract a file from a ZIP string

Question

I have a BASE64 string of a zip file that contains one single XML file.

Any ideas on how I could get the contents of the XML file without having to deal with files on the disk?

I would like very much to keep the whole process in the memory as the XML only has 1-5k.

It would be annoying to have to write the zip, extract the XML and then load it up and delete everything.

Answer 1

I had a similar problem, I ended up doing it manually.
https://www.pkware.com/documents/casestudies/APPNOTE.TXT

This extracts a single file (just the first one), no error/crc checks, assumes deflate was used.

// zip in a string
$data = file_get_contents('test.zip');

// magic
$head = unpack("Vsig/vver/vflag/vmeth/vmodt/vmodd/Vcrc/Vcsize/Vsize/vnamelen/vexlen", substr($data,0,30));
$filename = substr($data,30,$head['namelen']);
$raw = gzinflate(substr($data,30+$head['namelen']+$head['exlen'],$head['csize']));

// first file uncompressed and ready to use
file_put_contents($filename,$raw);