Determine path of the executing script

Question

I have a script called foo.R that includes another script other.R, which is in the same directory:

#!/usr/bin/env Rscript
message("Hello")
source("other.R")

But I want R to find that other.R no matter what the current working directory.

In other words, foo.R needs to know its own path. How can I do that?

Answer 1

Here there is a simple solution for the problem. This command:

script.dir <- dirname(sys.frame(1)$ofile)

returns the path of the current script file. It works after the script was saved.

Answer 2

You can use the commandArgs function to get all the options that were passed by Rscript to the actual R interpreter and search them for --file=. If your script was launched from the path or if it was launched with a full path, the script.name below will start with a '/'. Otherwise, it must be relative to the cwd and you can concat the two paths to get the full path.

Edit: it sounds like you'd only need the script.name above and to strip off the final component of the path. I've removed the unneeded cwd() sample and cleaned up the main script and posted my other.R. Just save off this script and the other.R script into the same directory, chmod +x them, and run the main script.

main.R:

#!/usr/bin/env Rscript
initial.options <- commandArgs(trailingOnly = FALSE)
file.arg.name <- "--file="
script.name <- sub(file.arg.name, "", initial.options[grep(file.arg.name, initial.options)])
script.basename <- dirname(script.name)
other.name <- file.path(script.basename, "other.R")
print(paste("Sourcing",other.name,"from",script.name))
source(other.name)

other.R:

print("hello")

output:

burner@firefighter:~$ main.R
[1] "Sourcing /home/burner/bin/other.R from /home/burner/bin/main.R"
[1] "hello"
burner@firefighter:~$ bin/main.R
[1] "Sourcing bin/other.R from bin/main.R"
[1] "hello"
burner@firefighter:~$ cd bin
burner@firefighter:~/bin$ main.R
[1] "Sourcing ./other.R from ./main.R"
[1] "hello"

This is what I believe dehmann is looking for.

Answer 3

I couldn't get Suppressingfire's solution to work when 'source'ing from the R console.
I couldn't get hadley's solution to work when using Rscript.

Best of both worlds?

thisFile <- function() {
        cmdArgs <- commandArgs(trailingOnly = FALSE)
        needle <- "--file="
        match <- grep(needle, cmdArgs)
        if (length(match) > 0) {
                # Rscript
                return(normalizePath(sub(needle, "", cmdArgs[match])))
        } else {
                # 'source'd via R console
                return(normalizePath(sys.frames()[[1]]$ofile))
        }
}