[Rd] Possibly broken system2 env-option

[peter dalgaard]

     On Windows, ‘env’ is only supported for commands such as ‘R’ and
     ‘make’ which accept environment variables on their command line.

So I suppose that would be tricky. 

The basic issue is that on Unix-alikes, system2 constructs a command like

FOO=bar cmd args

and passes that to sh via system(). On windoes, system() does not call sh, so system2() does (effectively)

cmd FOO=bar args

and hopes that cmd knows what to do with the env setting.

-pd

> On 19 Mar 2019, at 11:09 , Gábor Csárdi <csardi.gabor using gmail.com> wrote:
> 
> On Tue, Mar 19, 2019 at 9:59 AM peter dalgaard <pdalgd using gmail.com> wrote:
> [...]
>> What you need is something like (NB: single quotes!)
>>> system2("sh", env = c("VAR='Hello World'"), args = c("-c 'echo $VAR'"))
>> Hello World
> 
> Just out of curiosity, do you think it is possible to make this
> portable, assuming sh is available? On Windows it gives
> 
>> system2("sh", env = c("VAR='Hello World'"), args = c("-c 'echo $VAR'"))
> /rtools34/bin/sh: VAR=Hello World: No such file or directory
> Warning message:
> running command '"sh" VAR='Hello World' -c 'echo $VAR'' had status 127
> 
> G.

-- 
Peter Dalgaard, Professor,
Center for Statistics, Copenhagen Business School
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