Accessing WSL symlinks using R on Windows

Question

Is it possible to access a symlink created in WSL from an R session running on the Windows host?

I've made a symlink in WSL. The link is not broken. I can view the contents in WSL using nano /path_to_symlink/mylink.txt. I can even open an R session in WSL and read the contents into a variable with x <- readLines("/path_to_symlink/mylink.txt") and verify the contents are as expected. However, I can't do the same in RStudio running on the Windows host. I can read files from the Windows host if they are not symlinks. Trying to read the symlink from Windows results in the following error message. Is there any way I can run my script in Windows without this message? I have good reason not to run it in WSL, but that is what I plan to do for now.

Error in file(con, "r") : cannot open the connection
2. file(con, "r")
1. readLines("//wsl.localhost/Ubuntu-22.04/home/mylink.txt")

In addition: Warning message:
In file(con, "r") :
  cannot open file '//wsl.localhost/Ubuntu-22.04/home/mylink.txt': No such file or directory

I do see "mylink.txt" in the output of list.files("//wsl.localhost/Ubuntu-22.04/home/") when run from Windows.

Answer 1

I guess there's also a reason for not moving files out of WSL, which in turn might limit viable options. But ... for functions that handle URLs or connections, you could serve files from WSL over http.

Python http.server module as a server in WSL:

margusl@i:~/tmp$ ls -l
total 4
-rw-r--r-- 1 margusl margusl 145 Oct 22 01:17 file.txt
lrwxrwxrwx 1 margusl margusl   8 Oct 22 01:17 link.txt -> file.txt

margusl@i:~/tmp$ ip addr show eth0 | grep -w inet
    inet 172.22.204.92/20 brd 172.22.207.255 scope global eth0

margusl@i:~/tmp$ python3 -m http.server -b 172.22.204.92
Serving HTTP on 172.22.204.92 port 8000 (http://172.22.204.92:8000/) ...
172.22.192.1 - - [22/Oct/2025 01:17:59] "GET /file.txt HTTP/1.1" 200 -
172.22.192.1 - - [22/Oct/2025 01:17:59] "GET /link.txt HTTP/1.1" 200 -

R Session on Win host:

wsl_base <- r"(\\wsl.localhost\Ubuntu\home\margusl\tmp)"
url_base <- "http://172.22.204.92:8000"

# reading links fails:
list.files(wsl_base, pattern = "link", full.names = TRUE) |> readLines() 
#> Warning in file(con, "r"): cannot open file
#> '\\wsl.localhost\Ubuntu\home\margusl\tmp/link.txt': No such file or directory
#> Error in file(con, "r"): cannot open the connection

# file list through wsl path, file access over http:
( l <- list.files(wsl_base) )
#> [1] "file.txt" "link.txt"

file.path(url_base, l) |> 
  setNames(l) |> 
  print() |>
  lapply(readLines) |> 
  lapply(paste0, collapse = "\n") |>
  lapply(cat, "\n") |> 
  invisible()
#>                             file.txt                             link.txt 
#> "http://172.22.204.92:8000/file.txt" "http://172.22.204.92:8000/link.txt" 
#>  _____
#> < WSL >
#>  -----
#>         \   ^__^
#>          \  (oo)\_______
#>             (__)\       )\/\
#>                 ||----w |
#>                 ||     || 
#>  _____
#> < WSL >
#>  -----
#>         \   ^__^
#>          \  (oo)\_______
#>             (__)\       )\/\
#>                 ||----w |
#>                 ||     ||

# writing to file.txt, reading from link.txt url
write.table(head(mtcars), file.path(wsl_base, "file.txt"))
read.table(file.path(url_base, "link.txt"))
#>                    mpg cyl disp  hp drat    wt  qsec vs am gear carb
#> Mazda RX4         21.0   6  160 110 3.90 2.620 16.46  0  1    4    4
#> Mazda RX4 Wag     21.0   6  160 110 3.90 2.875 17.02  0  1    4    4
#> Datsun 710        22.8   4  108  93 3.85 2.320 18.61  1  1    4    1
#> Hornet 4 Drive    21.4   6  258 110 3.08 3.215 19.44  1  0    3    1
#> Hornet Sportabout 18.7   8  360 175 3.15 3.440 17.02  0  0    3    2
#> Valiant           18.1   6  225 105 2.76 3.460 20.22  1  0    3    1

it can get bit fiddly if you need to follow directory links, though http.server does provide listings. And it will follow links outside of server root - https://docs.python.org/3/library/http.server.html#security-considerations