Hi Even! That sounds cool. Is there also a function for retrieving all available files inside of a ZIP archive?
Kind regards, Kosta > -----Original Message----- > From: Even Rouault [mailto:[EMAIL PROTECTED] > Sent: Monday, August 25, 2008 11:41 PM > To: gdal-dev@lists.osgeo.org > Subject: [gdal-dev] Support for reading GDAL datasets in > compressed archives(.gz and .zip) > > Folks, > > I've just commited code in gdal 1.6.0dev SVN trunk that > enables GDAL to > decompress on-the-fly data from GZIP (.gz) and ZIP (.zip) archives. > > This is implemented as 2 virtual file systems (like /vsimem for > example), /vsigzip and /vsizip. Only read-only access is supported. > > Note that performance will not be very impressive, as random > access to ZIP > file is slow by nature, although some optimizations have been > made to make it > faster and generally usable. > > ---------------------------------- > To read from a .gz file, > ---------------------------------- > gdalinfo /vsigzip/path/to/the/file.gz were > path/to/the/file.gz is relative or > absolute. > > The first time that a .gz file is read, a small > .gz.properties file will be > generated (if possible) to capture the uncompressed data > size. This will make > following opening of that dataset much faster. > > -------------------------------------- > * To read from a .zip file, > ------------------------------------- > gdalinfo /vsizip/path/to/the/file.zip/path/inside/the/zip/file were > path/to/the/file.zip is relative or absolute and > path/inside/the/zip/file is > the relative path to the file inside the archive. > > For example gdalinfo /vsizip/myarchive.zip/subdir1/file1.tif > > The ReadDir() method is implemented for the .zip archives, so > a driver will be > able to find files relative to the given file inside the archive. For > example, you can read a CADRG dataset from the zipped archive > of the a.toc > file and all its NITF tiles. > > Small syntaxic sugar : if the .zip file contains only one > file located at its > root, just mentionning "/vsizip/path/to/the/file.zip" will work. > > ------------------------------------------------ > > The fact that this new capability is implemented as virtual > file systems imply > that it will only work for GDAL drivers supporting the "large > file API". A > list of such drivers is : PNG, JPEG, ILWIS, GTiff, GIF, > JP2KAK, NITF, ADRG, > DTED, SRTMHGT, BMP, LCP, HFA (Erdas Imagine), AAIGRID. Other > drivers may work > too (I just looked for those advertizing the > GDAL_DCAP_VIRTUALIO capability) > > (See http://trac.osgeo.org/gdal/ticket/1369 for the history > of that feature.) > > Best regards > > Even > > _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev