将Rscript中的布尔值输出到Bash变量中 [英] Output a boolean from an Rscript into a Bash variable

问题描述

我有一个输出TRUE或FALSE的R脚本.在R中，它使用的是真正的T/F数据类型，但是当我将其返回值回显给bash时，它似乎是一个字符串，说:

I have an R script that outputs TRUE or FALSE. In R, it's using a bona fide T/F data type, but when I echo its return value to bash, it seems to be a string, saying:

"[1]是"

或

"[1]错误"

它们都以[1]开头.[0]都不是，不是错字.无论如何，当我尝试在此Rscript的输出上测试以运行后续脚本时，其结果是什么，我必须将字符串与"[1] TRUE"进行如下字符串比较，而不是与"TRUE"或"1"，感觉更干净，更好.

They are both preceded by [1]. Neither is [0], that is not a typo. Anyway, the result of this is what when I try to test on the output of this Rscript to run a subsequent script, I have to do string comparison to "[1] TRUE" as below, instead of comparing to "TRUE" or "1" which feels cleaner and better.

A=$(Rscript ~/MyR.r)
echo $A
if [ "$A" == "[1] TRUE" ]; then
    bash SecondScript.sh
fi

如何使R输出真实的布尔值，或者Bash接受输出字符串并将其转换为0/1进行比较?也就是说，我宁愿测试...

How can I make R either output a true Boolean, or Bash accept the output string and convert it to 0/1 for comparison? That is, I'd rather test for...

if [ $A == TRUE ];

比

if [ "$A" == "[1] TRUE" ];

这是可行的，还是应该让我满意?

Is that possible, or should I be happy with this, how it is, which works?

*更新*

这是生成此脚本的Rscript的最小化版本.

Here's the minimalized version of the Rscript that generates this...

myinput <- TRUE #or FALSE

FunctionName <- function(test){
if (test == TRUE){
val <- TRUE
} else {
val <- FALSE
}
return(val)
}

FunctionName(myinput)

推荐答案

您应该使用 cat()不会在"TRUE"或"FALSE"前面加上"[1]".如果您想要0/1，则使用 cat(as.numeric(.)).尝试以下方法:

Instead of using either print() or the implicit print()-ing that occurs when an object name is offered to the R interpreter, you should be using cat() which will not prepend the "[1] " in front of either TRUE or FALSE. If you want 0/1, then use cat(as.numeric(.)). Try this instead:

myinput <- TRUE #or FALSE
FunctionName <- function(test){
   if (test == TRUE){
              val <- TRUE
                    } else {
              val <- FALSE
            }
   cat(as.numeric(val))
}
FunctionName(myinput)

如果您需要该值以进行进一步处理，则也可以使用以下方法:

If you needed that value for further processing you could also use this:

cat(as.numeric(val)); invisible(val)

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