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?
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
我喜欢steamer25的解决方案,因为它似乎是最健壮的。然而,当在RStudio中调试时(在windows中),路径不会被正确设置。原因是,如果在RStudio中设置了断点,那么源文件将使用另一个“调试源”命令,该命令将脚本路径设置得稍微不同。下面是我目前正在使用的最终版本,它解释了调试时RStudio中的这种替代行为:
# @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))
}
}
}
其他回答
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')
令人惊讶的是R中没有“$0”类型结构!你可以通过system()调用一个用R编写的bash脚本来实现:
write.table(c("readlink -e $0"), file="scriptpath.sh",col=F, row=F, quote=F)
thisscript <- system("sh scriptpath.sh", intern = TRUE)
然后将scriptpath.sh名称拆分为other。R
splitstr <- rev(strsplit(thisscript, "\\/")[[1]])
otherscript <- paste0(paste(rev(splitstr[2:length(splitstr)]),collapse="/"),"/other.R")
这个问题有一个简单的解决办法。这个命令:
script.dir <- dirname(sys.frame(1)$ofile)
返回当前脚本文件的路径。它在保存脚本后工作。
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))
}
})()
99%的情况你可以简单地使用:
sys.calls()[[1]] [[2]]
它将不适用于脚本不是第一个参数的疯狂调用,即source(some args, file="myscript")。在这些奇特的情况下使用@hadley's。