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
#!/usr/bin/env Rscript
print("Hello")
# sad workaround but works :(
programDir <- dirname(sys.frame(1)$ofile)
source(paste(programDir,"other.R",sep='/'))
source(paste(programDir,"other-than-other.R",sep='/'))
其他回答
参见R.utils包的findSourceTraceback()，其中
查找source()在所有调用帧中生成的所有'srcfile'对象。 这使得可以找出当前由source()编写脚本的文件。
I would use a variant of @steamer25 's approach. The point is that I prefer to obtain the last sourced script even when my session was started through Rscript. The following snippet, when included on a file, will provided a variable thisScript containing the normalized path of the script. I confess the (ab)use of source'ing, so sometimes I invoke Rscript and the script provided in the --file argument sources another script that sources another one... Someday I will invest in making my messy code turns into a package.
thisScript <- (function() {
lastScriptSourced <- tail(unlist(lapply(sys.frames(), function(env) env$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')
Supressingfire回答的简化版本:
source_local <- function(fname){
argv <- commandArgs(trailingOnly = FALSE)
base_dir <- dirname(substring(argv[grep("--file=", argv)], 8))
source(paste(base_dir, fname, sep="/"))
}
