[R] Looking for simple line-splitting code

[Rui Barradas]

Às 13:44 de 05/02/2025, Duncan Murdoch escreveu:
> If I have this object:
> 
>    x <- c("abc\ndef", "", "ghi")
> 
> and I write it to a file using `writeLines(x, "test.txt")`, my text 
> editor sees a 5 line file:
> 
>    1: abc
>    2: def
>    3:
>    4: ghi
>    5:
> 
> which is what I'd expect:  the last line in the editor is empty.  If I 
> use `readLines("test.txt")` on that file, I get the vector
> 
>    c("abc", "def", "", "ghi")
> 
> and all of that is fine.
> 
> What I'm looking for is simple code that modifies x to the `readLines()` 
> output, without actually writing and reading it.
> 
> My first attempt doesn't work:
> 
>    unlist(strsplit(x, "\n"))
> 
> because it leaves out the blank line 3.  I can fix that with this ugly 
> code:
> 
>    lines <- strsplit(x, "\n")
>    lines[sapply(lines, length) == 0] <- list("")
>    lines <- unlist(lines)
> 
> Surely there's a simpler way to do this?  I'd like to use just base 
> functions, no other packages.
> 
> Duncan Murdoch
> 
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Hello,

Use ?textConnection.
The 5th line is left out, just like in your code.


x <- c("abc\ndef", "", "ghi")
x |> textConnection() |> readLines()
# [1] "abc" "def" ""    "ghi"


Hope this helps,

Rui Barradas



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