Error in : Clipboard on X11 requires that the DISPLAY envvar be configured

Question

I'm writing a shinyapp in which I would like to put an actionbutton to copy some code (I'm using shinyace). When I run my app for the first time, on a new session, it works fine. But when I close it and run it again, I've got an error :

Error in : Clipboard on X11 requires that the DISPLAY envvar be configured

I installed the xclip and xsel but the problem still exists. When I deploy my app with Shinyapps.io, I'm disconnected each time I want to use the copy-to-clipboard function.

Here are my sessionInfo() and capabilities() :

R version 3.6.1 (2019-07-05)
Platform: x86_64-pc-linux-gnu (64-bit)
Running under: Ubuntu 18.04.2 LTS

Matrix products: default
BLAS:   /usr/lib/x86_64-linux-gnu/blas/libblas.so.3.7.1
LAPACK: /usr/lib/x86_64-linux-gnu/lapack/liblapack.so.3.7.1

locale:
 [1] LC_CTYPE=fr_FR.UTF-8       LC_NUMERIC=C               LC_TIME=fr_FR.UTF-8       
 [4] LC_COLLATE=fr_FR.UTF-8     LC_MONETARY=fr_FR.UTF-8    LC_MESSAGES=fr_FR.UTF-8   
 [7] LC_PAPER=fr_FR.UTF-8       LC_NAME=C                  LC_ADDRESS=C              
[10] LC_TELEPHONE=C             LC_MEASUREMENT=fr_FR.UTF-8 LC_IDENTIFICATION=C       

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] rsconnect_0.8.13 clipr_0.6.0      shinyAce_0.4.0   shiny_1.3.2     

loaded via a namespace (and not attached):
 [1] Rcpp_1.0.1      packrat_0.5.0   digest_0.6.20   later_0.8.0     bitops_1.0-6   
 [6] mime_0.7        R6_2.4.0        jsonlite_1.6    xtable_1.8-4    magrittr_1.5   
[11] rlang_0.4.0     rstudioapi_0.10 promises_1.0.1  tools_3.6.1     RCurl_1.95-4.12
[16] httpuv_1.5.1    compiler_3.6.1  askpass_1.1     htmltools_0.3.6 openssl_1.4 

jpeg         png        tiff       tcltk         X11        aqua    http/ftp     sockets 
TRUE        TRUE        TRUE        TRUE        TRUE       FALSE        TRUE        TRUE 
     libxml        fifo      cledit       iconv         NLS     profmem       cairo         ICU 
       TRUE        TRUE        TRUE        TRUE        TRUE        TRUE        TRUE        TRUE 
long.double     libcurl 
       TRUE        TRUE 

Do you know how to solve this problem ?

I also asked here : https://community.rstudio.com/t/error-in-clipboard-on-x11-requires-that-the-display-envvar-be-configured/34894

Answer 1

I suggest using xclip in a custom function as I do not know how to pass the DISPLAY var to clipr::write_clip():

clipboard<-function(x, sep="\t", row.names=FALSE, col.names=F){
  con <- pipe("xclip -selection clipboard -i  -display :1", open="w") # note the 1 here
  #writeChar(x, con)  # for strings
  write.table(x, con, sep=sep, row.names=row.names, col.names=col.names) # for table
  close(con)
}

My experience is: my rstudio server must use the display that the linux terminal uses.

When I put in the linux terminal

echo $DISPLAY

gives me :1 and this works:

echo 1235 | xclip -sel clip

But inside Rstudio-server, in its system terminal $DISPLAY gives me :0 and xclip line fails. It only works in RStudio-server after changing to DISPLAY=:1 in RStudio-server system terminal or with the -display flag in the above function

The fact that the first time you use it, works, make me suggest to use a counter to increase the number of the display each time and see what happens.