[PATCH] add information on subdataset support to gdal driver metadata

[etourigny]

The following patch implements the DMD_SUBDATASETS metadata item for any driver which supports subdatasets. This information is printed when gdalinfo --frmt <driver> is called.

Just submitting this for review - also would it make sense to apply to 1.9 ?

I have searched for drivers supporting subdatasets with the following command, and rapid inspection of each driver - it might not be 100% accurate.

I have also updated the docs to show that information on the formats list page.

example with hdf4:

$ gdalinfo --format hdf4
Format Details:
  Short Name: HDF4
  Long Name: Hierarchical Data Format Release 4
  Extension: hdf
  Help Topic: frmt_hdf4.html
  Supports: Subdatasets

[etourigny]

command used to search for subdataset support:

grep SUBDATASETS frmts/*/*.cpp

[etourigny]

second patch with changes suggested be Even, removing changes to formats_list.html and adding output to --formats commandline option

[etourigny]

Attached a slightly modified patch, Even could you please review, I have made a few small changes to the docs and also the output of gdalinfo --formats

e.g.

$ gdalinfo --formats
Supported Formats:
  VRT (rw+v): Virtual Raster
  GTiff (rw+vs): GeoTIFF

[Even Rouault]

2 remarks:

• why do you mention "in read-only mode" regarding subdatasets ? While it is probably true for the majority of drivers, a few formats have support for update mode for subdatasets, for example NITF subdatasets (actually that's the only one I have in mind)
• There's another place in swig/include/gdalconst.i where DMD_SUBDATASETS should be defined (there's a %ifdef depending on the SWIG language)

[etourigny]

ok, thanks. I wasn't able to test the bindings though.

Applied in r25494