I've checked in an experimental fix for this (75413). The newline was
lost in the shell script wrapper for R, it is now being escaped
similarly to space. To pass multiple commands to Rscript, one can also
use "-e" multiple times.
Tomas
On 09/17/2018 01:09 PM, Duncan Murdoch wrote:
On 16/09/2018 4:53 AM, Voeten, C.C. wrote:
Hello,
I have found what I believe to be a bug in the Linux version of the
Rscript binary.
Under Windows (official 64-bit 3.5.1 R distribution running on an
up-to-date Win10), I can do the following (e.g. under powershell):
PS H:\Users\Cesko> Rscript -e 'ls()
ls()'
character(0)
character(0)
which works as I expect: I am running Rscript with two arguments,
namely (1) '-e', and (2) two lines of code to be run, and it indeed
executes those two lines of code.
This fails when attempted on a Linux build (amd64, compiled from the
official 3.5.1 sources, but also reproducible with today's r-devel
snapshot):
$ Rscript -e 'ls()
ls()'
ARGUMENT 'ls()' __ignored__
character(0)
This behavior is not what I expected. Have I found a bug, or am I
simply using it wrong?
I would not assume that shell behaviour in Windows and Unix would
always be the same. A better comparison would be to list some other
command on the same system that behaves differently. For example, on
MacOS I see
$ echo 'ls()
> ls()'
ls()
ls()
which suggests that what you wrote should be legal, but the form of
that command is different: there's no equivalent of "-e". Maybe
someone else who knows Unix shell behaviour better can comment on
whether they'd expect your Rscript command to work.
By the way, if you just want multiple commands to execute, you can
separate them by semi-colons, and that does work:
$ Rscript -e 'ls(); ls()'
character(0)
character(0)
And I see this, which may explain the original problem:
$ Rscript -e 'commandArgs(); ls()'
[1] "/Library/Frameworks/R.framework/Resources/bin/exec/R"
[2] "--slave"
[3] "--no-restore"
[4] "-e"
[5] "commandArgs();~+~ls()"
character(0)
Notice that argument 5 includes both commands, whereas with the
newline they are separated:
$ Rscript -e 'commandArgs()
> ls()'
ARGUMENT 'ls()' __ignored__
[1] "/Library/Frameworks/R.framework/Resources/bin/exec/R"
[2] "--slave"
[3] "--no-restore"
[4] "-e"
[5] "commandArgs()"
[6] "ls()"
And finally, this also works:
Rscript -e 'ls()
-e
ls()'
Duncan Murdoch
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