为什么(或何时)Rscript(或更小)比R CMD BATCH 更好? [英] Why (or when) is Rscript (or littler) better than R CMD BATCH?

问题描述

我在 cron 中使用 R 自动化一些网页抓取，有时我使用 R CMD BATCH 有时我使用 Rscript.

I am automating some webscraping with R in cron and sometimes I use R CMD BATCH and sometimes I use Rscript.

决定使用哪个我主要关注是否需要 .Rout 文件.

To decide which one to use I mainly focus if I want the .Rout file or not.

但是在 SO 中阅读某些问题的答案(例如 this 或 this) 似乎 Rscript 优于 R CMD BATCH.

But reading the answers to some questions here in SO (like this or this) it seems that Rscript is preferred to R CMD BATCH.

所以我的问题是:

• 除了语法有点不同，R CMD BATCH 保存了一个 .Rout 文件，而 Rscript 没有，两者的主要区别是什么?

• Besides the fact that the syntax is a little different and R CMD BATCH saves an .Rout file while Rscript does not, what are the main differences between the two of them?

我什么时候应该更喜欢一个?更具体地说，在上面提到的 cron 作业中，是否首选其中之一?

When should I prefer one over another? More specifically, in the cron job above mentioned, is one of them preferred?

我还没用过little，它和Rscript和R CMD BATCH有什么区别?

I have not used yet littler, how is it different from both Rscript and R CMD BATCH?

推荐答案

R CMD BATCH 是我们多年前的全部.它使 i/o 变得非常困难并留下文件.

R CMD BATCH is all we had years ago. It makes i/o very hard and leaves files behind.

事情变得更好了，首先是 littler，然后是 Rscript.两者都可以用于shebang"行，例如

Things got better, first with littler and then too with Rscript. Both can be used for 'shebang' lines such as

 #!/usr/bin/r

 #!/usr/bin/Rscript

并且两者都可以与诸如 getopt 和 optparse 之类的包一起使用 --- 允许您编写可以充当命令的适当 R 脚本.如果有几十个，从这样的简单开始，我可以将其称为 install.r pkga pkgb pkgc 并且将从命令行为我安装所有三个及其依赖项)，而不会占用R 提示:

and both can be used with packages like getopt and optparse --- allowing you to write proper R scripts that can act as commands. If have dozens of them, starting with simple ones like this which I can call as install.r pkga pkgb pkgc and which will install all three and their dependencies) for me from the command-line without hogging the R prompt:

#!/usr/bin/env r       
#
# a simple example to install one or more packages 

if (is.null(argv) | length(argv)<1) {
  cat("Usage: installr.r pkg1 [pkg2 pkg3 ...]
")
  q()
}

## adjust as necessary, see help('download.packages') 
repos <- "http://cran.rstudio.com"

## this makes sense on Debian where no packages touch /usr/local 
lib.loc <- "/usr/local/lib/R/site-library"

install.packages(argv, lib.loc, repos)

和 Karl 一样，我也有调用类似 R 脚本的 cronjobs.

And just like Karl, I have cronjobs calling similar R scripts.

于 2015-11-04 截至上周，littler 现在也在 CRAN 上.

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