g2ctl (not making .idx file)

[Ji-Yun SEO]

Hi Grads users!!!

 I tried to display GFS file with g2ctl and gribmap command.
"g2ctl  gfs.grib2 > test.ctl"
"gribmap -i test.ctl "

But these error massage came out...
-----------------------------------------------
open Error:  Data file type invalid
  --> The invalid description file record is:
  --> dtype grib2
  The data file was not opened
-----------------------------------------------

My GrADS version is "grads-2.0.a6" and I also have wgrib2

I also tried to " g2ctl gfs.grib2 gfs.grib2.idx > test.ctl",

.idx file was not generated.

I am very grateful if somebody give me the solution!!!
Thank you in advance~