Question

I want to redirect all console text to a file. Here is what I tried:

> sink("test.log", type=c("output", "message"))
> a <- "a"
> a
> How come I do not see this in log
Error: unexpected symbol in "How come"

Here is what I got in test.log:

[1] "a"

Here is what I want in test.log:

> a <- "a"
> a
[1] "a"
> How come I do not see this in log
Error: unexpected symbol in "How come"

What am I doing wrong? Thanks!

Answer 1

You have to sink “output” and “message” separately (the sink function only looks at the first element of type)

Now if you want the input to be logged too, then put it in a script:

script.R

1:5 + 1:3   # prints and gives a warning
stop("foo") # an error

And at the prompt:

con <- file("test.log")
sink(con, append=TRUE)
sink(con, append=TRUE, type="message")

# This will echo all input and not truncate 150+ character lines...
source("script.R", echo=TRUE, max.deparse.length=10000)

# Restore output to console
sink() 
sink(type="message")

# And look at the log...
cat(readLines("test.log"), sep="\n")