While it is too late for your project, I will mention the wgrib2 package, which you could run from the Matlab command line using the ! character as shown below. If you want to list out the lat/lon grid of a grib2 file called multi_1.glo_30m.hs.200502.grb2, all you need to do is use the -grid option:
!"C:\Program Files (x86)\wgrib\wgrib2.exe" multi_1.glo_30m.hs.200502.grb2 -grid
On my windows machine I had to put the full path to the wgrib2 executable which is in the quotes, but your implementation may not need that. There are many other things you can do with wgrib2. If you just type the following you will list them all.
!"C:\Program Files (x86)\wgrib\wgrib2.exe"