Rscript: 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
print("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

I liked steamer25's solution as it seems the most robust for my purposes. However, when debugging in RStudio (in windows), the path would not get set properly. The reason being that if a breakpoint is set in RStudio, sourcing the file uses an alternate "debug source" command which sets the script path a little differently. Here is the final version which I am currently using which accounts for this alternate behavior within RStudio when debugging:

# @return full path to this script
get_script_path <- function() {
    cmdArgs = commandArgs(trailingOnly = FALSE)
    needle = "--file="
    match = grep(needle, cmdArgs)
    if (length(match) > 0) {
        # Rscript
        return(normalizePath(sub(needle, "", cmdArgs[match])))
    } else {
        ls_vars = ls(sys.frames()[[1]])
        if ("fileName" %in% ls_vars) {
            # Source'd via RStudio
            return(normalizePath(sys.frames()[[1]]$fileName)) 
        } else {
            # Source'd via R console
            return(normalizePath(sys.frames()[[1]]$ofile))
        }
    }
}

Answer 2

My all in one!

#' current script file (in full path)
#' @param
#' @return
#' @examples
#' works with Rscript, source() or in RStudio Run selection
#' @export
csf <- function() {
    # http://stackoverflow.com/a/32016824/2292993
    cmdArgs = commandArgs(trailingOnly = FALSE)
    needle = "--file="
    match = grep(needle, cmdArgs)
    if (length(match) > 0) {
        # Rscript via command line
        return(normalizePath(sub(needle, "", cmdArgs[match])))
    } else {
        ls_vars = ls(sys.frames()[[1]])
        if ("fileName" %in% ls_vars) {
            # Source'd via RStudio
            return(normalizePath(sys.frames()[[1]]$fileName)) 
        } else {
            if (!is.null(sys.frames()[[1]]$ofile)) {
            # Source'd via R console
            return(normalizePath(sys.frames()[[1]]$ofile))
            } else {
                # RStudio Run Selection
                # http://stackoverflow.com/a/35842176/2292993  
                return(normalizePath(rstudioapi::getActiveDocumentContext()$path))
            }
        }
    }
}

Answer 3

You can wrap the r script in a bash script and retrieve the script's path as a bash variable like so:

#!/bin/bash
     # [environment variables can be set here]
     path_to_script=$(dirname $0)

     R --slave<<EOF
        source("$path_to_script/other.R")

     EOF

Answer 4

I like this approach:

this.file <- sys.frame(tail(grep('source',sys.calls()),n=1))$ofile
this.dir <- dirname(this.file)

Answer 5

I would use a variant of @steamer25 's approach. The point is that I prefer to obtain the last sourced script even when my session was started through Rscript. The following snippet, when included on a file, will provided a variable thisScript containing the normalized path of the script. I confess the (ab)use of source'ing, so sometimes I invoke Rscript and the script provided in the --file argument sources another script that sources another one... Someday I will invest in making my messy code turns into a package.

thisScript <- (function() {
  lastScriptSourced <- tail(unlist(lapply(sys.frames(), function(env) env$ofile)), 1)

  if (is.null(lastScriptSourced)) {
    # No script sourced, checking invocation through Rscript
    cmdArgs <- commandArgs(trailingOnly = FALSE)
    needle <- "--file="
    match <- grep(needle, cmdArgs)
    if (length(match) > 0) {
      return(normalizePath(sub(needle, "", cmdArgs[match]), winslash=.Platform$file.sep, mustWork=TRUE))
    }
  } else {
    # 'source'd via R console
    return(normalizePath(lastScriptSourced, winslash=.Platform$file.sep, mustWork=TRUE))
  }
})()

Answer 6

I have wrapped up and extended the answers to this question into a new function thisfile() in rprojroot. Also works for knitting with knitr.