Grand thanks for the pointers. - Alasdair King Research Computing Specialist
> On 8 Nov 2017, at 14:51, Henri Doreau <henri.dor...@cea.fr> wrote: > > Well, technically you can do so if for some reason you have to use a > path (for instance if a submodule requires that), but it's pointless > to re-open a FD that you already have... > > If you want a python file object you can use os.fdopen, otherwise you > can use the fd directly. > > I'd suggest you have a look at the google drive command that the Stanford > Research Computing Group developed for lhsmtool_cmd, it's an excellent > example: https://github.com/stanford-rc/ct_gdrive > > Henri > > On 08/nov. - 14:20 Alasdair King wrote: >> Hi Henri, thanks for geting back to me. I had managed to get DD to >> work with the cmd, but I had to locate the file discripter in the fd >> directory in proc ( dd if=/proc/self/fd/{fd} ). If im writing a tool >> in python is it expected for the FD to be handeld in a similler >> fashion? >> >> Kind Regards >> - Alasdair King >> Research Computing Specialist >> University Information Services >> Roger Needham Building >> JJ Thompson Avenue >> University of Cambridge >> Cambridge >> Email: ajk...@cam.ac.uk >> Tel: +441223746559 >> >>> On 8 Nov 2017, at 12:54, Henri Doreau <henri.dor...@cea.fr> wrote: >>> >>>> Hi I am looking to make use of the lhsmtool_cmd, and im having trouble >>>> understanding the use of the FD(File Descripter) varable requierd by >>>> the tool. Is there anyone that can assist with my understanding? I'v >>>> had a look unsuccessfully and at some examples, as well as run the >>>> example with DD. >>>> >>>> Kind Regards >>>> >>>> - Alasdair King >>> >>> Hi, >>> >>> The FD is a file descriptor (integer) where the subprocess (the command >>> which is spawned by the copytool) can read or write - depending whether >>> it is archiving or restoring - data in Lustre. >>> >>> It is opened by the parent process, which receives and processes >>> requests from the coordinator and passed to the subcommand so that it >>> does not have to re-open the file. Internally, it is provided by >>> llapi_hsm_action_get_fd(). >>> >>> Because we want to be able to invoke arbitrary commands, we cannot use >>> the standard sendmsg/recvmsg to pass FDs between processes and instead >>> rely on /proc/self/{fd} to work with commands that expect paths, like >>> dd. >>> >>> Hope this makes sense >>> Regards >>> >>> -- >>> Henri >> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ robinhood-support mailing list robinhood-support@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/robinhood-support
