Remote process execution

Remote process execution

[Aidan Gauland]

I am trying to modify a third-party package to work over TRAMP, and I am 
stuck on `call-process-region'.  I seem to be able to use `process-file' 
as a drop-in replacement for `call-process', but there does not appear 
to be any substitute for `call-process-region'.  I did find 
`tramp-call-process-region' (and `tramp-call-process'), but these 
functions seem to be redundant, since they just call the process on the 
local host, which is what the non-tramp versions of these functions do 
already.

Can anyone offer advice on modifying code that uses 
`call-process-region' to handle remote-command-execution in TRAMP buffers?

Regards,
Aidan Gauland

Re: Remote process execution

[Michael Albinus]

Aidan Gauland <aidalgol@fastmail.net> writes:

Hi Aidan,

> I am trying to modify a third-party package to work over TRAMP, and I
> am stuck on `call-process-region'.  I seem to be able to use
> `process-file' as a drop-in replacement for `call-process', but there
> does not appear to be any substitute for `call-process-region'.  I did
> find `tramp-call-process-region' (and `tramp-call-process'), but these
> functions seem to be redundant, since they just call the process on
> the local host, which is what the non-tramp versions of these
> functions do already.

Like call-process, call-process-region does not support remote
directories. As you say, there is process-file, which does this with the
same arguments as call-process.

tramp-call-process and tramp-call-process-region are internal
functions. Their docstrings say clearly, that they are based on
call-process and call-process-region, respectively.

> Can anyone offer advice on modifying code that uses
> `call-process-region' to handle remote-command-execution in TRAMP
> buffers?

What you are looking for is an implementation for
process-file-region. That does not exist (yet?), AFAIK.

> Regards,
> Aidan Gauland

Best regards, Michael.

Re: Remote process execution

[Tomas Hlavaty]

On Thu 24 Jun 2021 at 20:01, Michael Albinus <michael.albinus@gmx.de> wrote:
> Aidan Gauland <aidalgol@fastmail.net> writes:
>> Can anyone offer advice on modifying code that uses
>> `call-process-region' to handle remote-command-execution in TRAMP
>> buffers?
>
> What you are looking for is an implementation for
> process-file-region. That does not exist (yet?), AFAIK.

what about process-file-shell-command with pipe, something like this:

(format "head -c %d | tail -c %d | program" end (- end begin))

it's far from perfect but might do for your use-case

Re: Remote process execution

[Philipp]

> Am 23.06.2021 um 00:29 schrieb Aidan Gauland <aidalgol@fastmail.net>:
> 
> I am trying to modify a third-party package to work over TRAMP, and I am stuck on `call-process-region'.  I seem to be able to use `process-file' as a drop-in replacement for `call-process', but there does not appear to be any substitute for `call-process-region'.  I did find `tramp-call-process-region' (and `tramp-call-process'), but these functions seem to be redundant, since they just call the process on the local host, which is what the non-tramp versions of these functions do already.
> 
> Can anyone offer advice on modifying code that uses `call-process-region' to handle remote-command-execution in TRAMP buffers?

What I typically do is write the region into a temporary file (using `make-nearby-temp-file' and `write-region') and then call `process-file'.