我有一个名为foo的脚本。R包含另一个脚本other。R,在同一个目录下:

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

但我想让R找到另一个。R,不管当前工作目录是什么。

换句话说,就是foo。R需要知道自己的路径。我该怎么做呢?


当前回答

我的一切都在一个!(—2019年9月1日更新以处理RStudio控制台)

#' current script file (in full path)
#' @description current script file (in full path)
#' @examples
#' works with Rscript, source() or in RStudio Run selection, RStudio Console
#' @export
ez.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]]$ofile))
            } else {
                # RStudio Run Selection
                # http://stackoverflow.com/a/35842176/2292993
                pth = rstudioapi::getActiveDocumentContext()$path
                if (pth!='') {
                    return(normalizePath(pth))
                } else {
                    # RStudio Console
                    tryCatch({
                            pth = rstudioapi::getSourceEditorContext()$path
                            pth = normalizePath(pth)
                        }, error = function(e) {
                            # normalizePath('') issues warning/error
                            pth = ''
                        }
                    )
                    return(pth)
                }
            }
        }
    }
}

其他回答

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))
  }
})()

我已经将这个问题的答案打包并扩展为rprojroot中的新函数thisfile()。也适用于编织与针织。

只是在上面的答案的基础上,作为安全检查,您可以添加一个包装器,当sys.frame(1)失败时(如果interactive() == TRUE可能会失败),或者源脚本不在主脚本所期望的位置时,它会要求用户找到文件。

fun_path = tryCatch(expr = 
                      {file.path(dirname(sys.frame(1)$ofile), "foo.R")},
                    error = function(e){'foo.R'}
                    )
if(!file.exists(fun_path))
{
  msg = 'Please select "foo.R"'
  # ask user to find data
  if(Sys.info()[['sysname']] == 'Windows'){#choose.files is only available on Windows
    message('\n\n',msg,'\n\n')
    Sys.sleep(0.5)#goes too fast for the user to see the message on some computers
    fun_path  = choose.files(
      default = file.path(gsub('\\\\', '/', Sys.getenv('USERPROFILE')),#user
                          'Documents'),
      caption = msg
    )
  }else{
    message('\n\n',msg,'\n\n')
    Sys.sleep(0.5)#goes too fast for the user to see the message on some computers
    fun_path = file.choose(new=F)
  }
}
#source the function
source(file = fun_path, 
       encoding = 'UTF-8')

这对我很有用

library(rstudioapi)    
rstudioapi::getActiveDocumentContext()$path

我也有这个问题,上面的解决方案都不适合我。也许是来源之类的,但还不够清楚。

我找到了这个,对我来说很优雅的解决方案:

paste0(gsub("\\", "/", fileSnapshot()$path, fixed=TRUE),"/")

其中重要的是fileSnapshot(),它提供了关于文件的大量信息。它返回一个包含8个元素的列表。当您选择path作为列表元素时,路径将以\\作为分隔符返回,因此其余代码只是更改这一点。

我希望这能有所帮助。