Re: hack to run ferret on RO FS. (Was Re: Ferret open .jnl file rw ?)

[Olivier ARCHER <olivier.archer@xxxxxxxxxx>]

Kevin O'Brien wrote:
> Forwarded message for the benefit of the Ferret archives.....
>
>
> -------- Original Message --------
> Subject: Re: hack to run ferret on RO FS. (Was Re: Ferret open .jnl file 
> rw ?)
> Date: Wed, 07 May 2003 09:14:57 -0700
> From: Kevin O'Brien <Kevin.M.O'Brien@noaa.gov>
> To: Olivier ARCHER <olivier.archer@ifremer.fr>
> CC: contact_ferret@pmel.noaa.gov
> References: <3EA9009C.4020902@ifremer.fr> <3EAFE2C2.90908@ifremer.fr> 
> <3EB237FD.7090705@ifremer.fr> <3EB92EA0.5070407@ifremer.fr>
>
>
>
> Hi Olivier -
>
> I have also been looking a this problem.  It turns out that the problem is caused by
> the NAG f95 compiler not having a "READONLY" file open specifier.  I myself am looking
> into solving this problem.
>
> However, the g77 version of Ferret for linux does not have the same problem.  Perhaps
> this would solve the issue for you?  If you have built your own external functions
> using f95, you'd have to recompile them with g77 in order to use them with this
> version of Ferret, but I believe that is the only complication.
>
> You can get the g77 version of Ferret at:
>
>     http://www.ferret.noaa.gov/Ferret/Downloads/beta_releases.html
>
> Although it's listed as a beta, it has passed all the testing benchmarks......
>
> Let me know if you have any questions or problems -
>
> Thanks -
>
> Kevin
Kevin,
	Thanks, it is now ok for me. Seem to works well with DODS/LAS too.

So the ERROFS error is a compiler side bug, not ferret side. I've tried 
different fortan compiler to open file on read only filesystem. they all 
say:

open("/mnt/rofs/file", O_RDWR)= -1 EROFS (Read-only file system)
open("/mnt/rofs/file", O_RDONLY)           = 3

buf NAG f95 say just:
open("/mnt/rofs/file", O_RDWR)= -1 EROFS (Read-only file system)

I've take a look at g77 source. g77 tries to open file RO on *any* error 
opening it RW. NAG f95 probably just check EACCES error. unfortunatly, 
nag f95 is not open source, and i can't go ahead.

The readonly file open specifier seem to be a non-standard fortran 
extension. In this case, it will probably help. but we can see that we 
can open file RO under fortran with adapted file permission 
system-side... so is the readonly file open extension is necessary ? I 
will ask to the fortran community.

Thanks

--
Olivier