CODEWITHSUNDEEP
rwindowsregistrycontextmenuright-click
Matthew
Matthew

Reputation: 4339

How to add context menu option to start a program in the given working directory

When you install Git on windows, it adds a context menu option when you right-click on a folder to "Git Bash Here". The way it does this is by adding a registry key like this:

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\Directory\shell\git_shell\command]
@="\"C:\\Program Files\\Git\\git-bash.exe\" \"--cd=%1\""

Notice the cd argument at the end that passes the directory name to the program.

I would like to do something similar for R (and other programs). Unfortunately R doesn't accept a cd argument. This will launch R:

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\Directory\shell\R\command]
@="\"C:\\Program Files\\R\\R-3.4.3\\bin\\x64\\Rgui.exe\" \"--cd=%1\""

but it gives an error message saying the cd argument is not recognized, and Rgui will start with whatever the default working directory is, defeating the entire point.

What I really want it to do is the equivalent of this command:

start "R" /D %1 "C:\Program Files\R\R-3.4.3\bin\x64\Rgui.exe"

where %1 is the folder that was right-clicked on. Is this possible?

Upvotes: 0

Views: 401

Answers (1)

AEF
AEF

Reputation: 5650

You can write R code that runs on startup and checks the commandline arguments. You can put the following code at the end of C:\Program Files\R\R-3.4.3\etc\Rprofile.site (or any other file that gets executed at startup):

local({

  processArg <- function(arg) {
    parts <- strsplit(arg, "=")[[1]]
    if (length(parts) == 2) {
      if (parts[1] == "R_startup_wd") {
        setwd(parts[2])
      }
    }
  }

  invisible(sapply(commandArgs(FALSE), processArg))
})

It checks if R was called with an argument R_startup_wd=your_working_dir and changes the working directory if yes. You can then call R like

"C:\Program Files\R\R-3.4.3\bin\x64\Rgui.exe" "R_startup_wd=your_working_dir"

Note that the argument name is given without "--", i.e. we have R_startup_wd and not --R_startup_wd. Otherwise RGui will complain about "unknown arguments"

You can of course still use R without the argument given.

Upvotes: 3

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