Write lines of text to a file in R

Question

In the R scripting language, how do I write lines of text, e.g., the following two lines

Hello
World

to a file named "output.txt"?

Answer 1

fileConn<-file("output.txt")
writeLines(c("Hello","World"), fileConn)
close(fileConn)

Answer 2

Actually you can do it with sink():

sink("outfile.txt")
cat("hello")
cat("\n")
cat("world")
sink()

hence do:

file.show("outfile.txt")
# hello
# world

Answer 3

I would use the cat() command as in this example:

> cat("Hello",file="outfile.txt",sep="\n")
> cat("World",file="outfile.txt",append=TRUE)

You can then view the results from with R with

> file.show("outfile.txt")
hello
world

Answer 4

What's about a simple writeLines()?

txt <- "Hallo\nWorld"
writeLines(txt, "outfile.txt")

or

txt <- c("Hallo", "World")
writeLines(txt, "outfile.txt")

Answer 5

I suggest:

writeLines(c("Hello","World"), "output.txt")

It is shorter and more direct than the current accepted answer. It is not necessary to do:

fileConn<-file("output.txt")
# writeLines command using fileConn connection
close(fileConn)

Because the documentation for writeLines() says:

If the con is a character string, the function calls file to obtain a file connection which is opened for the duration of the function call.

# default settings for writeLines(): sep = "\n", useBytes = FALSE
# so: sep = "" would join all together e.g.

Answer 6

You could do that in a single statement

cat("hello","world",file="output.txt",sep="\n",append=TRUE)

Answer 7

Short ways to write lines of text to a file in R could be realised with cat or writeLines as already shown in many answers. Some of the shortest possibilities might be:

cat("Hello\nWorld", file="output.txt")
writeLines("Hello\nWorld", "output.txt")

In case you don't like the "\n" you could also use the following style:

cat("Hello
World", file="output.txt")

writeLines("Hello
World", "output.txt")

While writeLines adds a newline at the end of the file what is not the case for cat. This behaviour could be adjusted by:

writeLines("Hello\nWorld", "output.txt", sep="") #No newline at end of file
cat("Hello\nWorld\n", file="output.txt") #Newline at end of file
cat("Hello\nWorld", file="output.txt", sep="\n") #Newline at end of file

But main difference is that cat uses R objects and writeLines a character vector as argument. So writing out e.g. the numbers 1:10 needs to be casted for writeLines while it can be used as it is in cat:

cat(1:10)
writeLines(as.character(1:10))

and cat can take many objects but writeLines only one vector:

cat("Hello", "World", sep="\n")
writeLines(c("Hello", "World"))

Append to an existing file is easier with cat.

cat("Hello\n", file="output.txt")
cat("World", file="output.txt", append=TRUE)

writeLines("Hello", "output.txt")
CON <- file("output.txt", "a")
writeLines("World", CON)
close(CON)

On the other hand writeLines is faster than cat.

bench::mark(check=FALSE,
writeLines(c("Hello", "World")),
cat("Hello", "World", sep="\n"),
writeLines(c("Hello", "World"), sep=" "),
cat(c("Hello", "World")),
cat("Hello", "World") )
#  expression                                      min   median `itr/sec` mem_a…¹
#  <bch:expr>                                 <bch:tm> <bch:tm>     <dbl> <bch:b>
#1 writeLines(c("Hello", "World"))              2.27µs   4.77µs   163878.      0B
#2 cat("Hello", "World", sep = "\n")            3.83µs   8.51µs   118708.      0B
#3 writeLines(c("Hello", "World"), sep = " ")   1.99µs   4.25µs   235944.      0B
#4 cat(c("Hello", "World"))                      4.1µs   6.84µs   141797.      0B
#5 cat("Hello", "World")                        3.46µs   7.06µs   129865.      0B

Answer 8

tidyverse edition with pipe and write_lines() from readr

library(tidyverse)
c('Hello', 'World') %>% write_lines( "output.txt")

Answer 9

What about a simple write.table()?

text = c("Hello", "World")
write.table(text, file = "output.txt", col.names = F, row.names = F, quote = F)

The parameters col.names = FALSE and row.names = FALSE make sure to exclude the row and column names in the txt, and the parameter quote = FALSE excludes those quotation marks at the beginning and end of each line in the txt. To read the data back in, you can use text = readLines("output.txt").

Answer 10

To round out the possibilities, you can use writeLines() with sink(), if you want:

> sink("tempsink", type="output")
> writeLines("Hello\nWorld")
> sink()
> file.show("tempsink", delete.file=TRUE)
Hello
World

To me, it always seems most intuitive to use print(), but if you do that the output won't be what you want:

...
> print("Hello\nWorld")
...
[1] "Hello\nWorld"

Answer 11

Based on the best answer:

file <- file("test.txt")
writeLines(yourObject, file)
close(file)

Note that the yourObject needs to be in a string format; use as.character() to convert if you need.

But this is too much typing for every save attempt. Let's create a snippet in RStudio.

In Global Options >> Code >> Snippet, type this:

snippet wfile
    file <- file(${1:filename})
    writeLines(${2:yourObject}, file)
    close(file)

Then, during coding, type wfile and press Tab.

Answer 12

The ugly system option

ptf <- function (txtToPrint,outFile){system(paste(paste(paste("echo '",cat(txtToPrint),sep = "",collapse = NULL),"'>",sep = "",collapse = NULL),outFile))}
#Prints txtToPrint to outFile in cwd. #!/bin/bash echo txtToPrint > outFile

Answer 13

In newer versions of R, writeLines will preserve returns and spaces in your text, so you don't need to include \n at the end of lines and you can write one big chunk of text to a file. This will work with the example,

txt <- "Hello
World"
fileConn<-file("output.txt")
writeLines(txt, fileConn)
close(fileConn)

But you could also use this setup to simply include text with structure (linebreaks or indents)

txt <- "Hello
   world
 I can 
   indent text!"
fileConn<-file("output.txt")
writeLines(txt, fileConn)
close(fileConn)