How to read .dat files with different filenames, please?

Hi,

I am using fortran for coding. Now I am going to read more than 1000 data files separately, from the data file folder D\Datas\fortran

And the data filenames are like:

Gstep00001.dat  Gstep00002.dat  ... Gstep01230.dat

and the contents are like:

    -0.0004349421733      1.0583843781537
    -0.0004059937166      1.0583825316509
    -0.0003770452599      1.0583806851481
    -0.0003480968032      1.0583788386453
    -0.0003191483465      1.0583769921425
    -0.0002901998898      1.0583751456397
    -0.0002612514331      1.0583732991369
    -0.0002323029764      1.0583714526341
    -0.0002033545197      1.0583696061313
    -0.0001744060630      1.0583677596285

....

....

So how to accomplish this in fortran, please? Waiting for your help, thanks!

Sinserely

Ren