I think there's a minor bug in the argument-processing carried out by Rscript. The effect is that if one passes "-g" as a flag to the script, it is erroneously exposed to the main executable's argument processing and therefore generates a message about not being able to comply with the request for a particular GUI. Uppercase G is fine as are the other 25 letters in upper or lower case. I noticed this with R-2.5.1 and carried out the tests below with R-devel-2.7.0. Dan platform i686-pc-linux-gnu arch i686 os linux-gnu system i686, linux-gnu status Under development (unstable) major 2 minor 7.0 year 2008 month 01 day 04 svn rev 43862 language R version.string R version 2.7.0 Under development (unstable) (2008-01-04 r43862) [fedora core 5] ## No problem with -a -b -f -h ~/src/scripts/R> /usr/src/R/R-devel/bin/Rscript -e "commandArgs()" -a -b -f -h [1] "/usr/src/R/R-devel/bin/exec/R" "--slave" [3] "--no-restore" "-e" [5] "commandArgs()" "--args" [7] "-a" "-b" [9] "-f" "-h" ## But if -g is in there, there's a warning message ~/src/scripts/R> /usr/src/R/R-devel/bin/Rscript -e "commandArgs()" -a -b -f -g -h WARNING: unknown gui '-h', using X11 [1] "/usr/src/R/R-devel/bin/exec/R" "--slave" [3] "--no-restore" "-e" [5] "commandArgs()" "--args" [7] "-a" "-b" [9] "-f" "-g" [11] "-h" ~/src/scripts/R> /usr/src/R/R-devel/bin/Rscript -e "commandArgs()" -a -b -f -g not_a_gui -h WARNING: unknown gui 'not_a_gui', using X11 [1] "/usr/src/R/R-devel/bin/exec/R" "--slave" [3] "--no-restore" "-e" [5] "commandArgs()" "--args" [7] "-a" "-b" [9] "-f" "-g" [11] "not_a_gui" "-h" ## The problem remains if the R code is in a file rather than in-line, ## and also with a #! style script: ~/src/scripts/R> cat test.R #!/usr/src/R/R-devel/bin/Rscript commandArgs() ~/src/scripts/R> ./test.R -a -g invalid_gui WARNING: unknown gui 'invalid_gui', using X11 [1] "/usr/src/R/R-devel/bin/exec/R" "--slave" [3] "--no-restore" "--file=./test.R" [5] "--args" "-a" [7] "-g" "invalid_gui" ~/src/scripts/R> cat test2.R commandArgs() ~/src/scripts/R> /usr/src/R/R-devel/bin/Rscript test2.R -a -g WARNING: --gui or -g without value ignored [1] "/usr/src/R/R-devel/bin/exec/R" "--slave" [3] "--no-restore" "--file=test2.R" [5] "--args" "-a" [7] "-g"
Rscript argument processing minor bug with -g
2 messages · Dan Davison, Dirk Eddelbuettel
9 days later
On 5 January 2008 at 19:34, Dan Davison wrote:
| I think there's a minor bug in the argument-processing carried out by Rscript. | The effect is that if one passes "-g" as a flag to the script, it is erroneously | exposed to the main executable's argument processing and therefore generates a | message about not being able to comply with the request for a particular GUI. | Uppercase G is fine as are the other 25 letters in upper or lower case. | | I noticed this with R-2.5.1 and carried out the tests below with R-devel-2.7.0. [...] | ~/src/scripts/R> /usr/src/R/R-devel/bin/Rscript -e "commandArgs()" -a -b -f -g -h | WARNING: unknown gui '-h', using X11 | | [1] "/usr/src/R/R-devel/bin/exec/R" "--slave" | [3] "--no-restore" "-e" | [5] "commandArgs()" "--args" | [7] "-a" "-b" | [9] "-f" "-g" | [11] "-h" For what it's worth, littler does not have that problem with Following GNU traditions, we stick all arguments that are not referring to existing switches into the argv vector which you can access normally: edd at ron:~> r -e 'print(argv)' -- -a -b -f -g -h -i -j [1] "-a" "-b" "-f" "-g" "-h" "-i" "-j" It is then up to you to parse these remaining arguments. If you hit an existing option like -h _before_ the --, its code gets invoked. This also works when code is piped into littler (when '-' is used to turn on stdin parsing): edd at ron:~> echo 'print(argv)' | r - -- -a -b -f -g -h -i -j [1] "-a" "-b" "-f" "-g" "-h" "-i" "-j" Prior versions had an off-by-one error in the way argv was built, but version 0.1.0 which I just put onto http://dirk.eddelbuettel.com/code/littler.html should be fine. Hope this helps, Dirk
Three out of two people have difficulties with fractions.