Question

I have two folders, folder1 and folder2 with around 200 files each that are either *rda or *R. I want to read all of the files and datasets from the two directories. How can I do that?

Paths for:

folder1:  C:\folder1
folder2:  C:\folder2 

My trial

setwd("C:/folder1")
myls <- ls() # do work as this will only list that are already loaded in the system 
setwd("C:/folder2")
myls2 <- ls()
myls  # do work as this will only list that are already loaded in the system 

I know this is simple question, but I do not have any answer.

Answer 1

Since .rda requires load and .R requires source, I would do something like this:

file.sources = list.files(pattern="*.R")
data.sources = list.files(pattern="*.rda")
sapply(data.sources,load,.GlobalEnv)
sapply(file.sources,source,.GlobalEnv)

Update for reading from multiple folders at once

file.sources = list.files(c("C:/folder1", "C:/folder2"), 
                          pattern="*.R$", full.names=TRUE, 
                          ignore.case=TRUE)
data.sources = list.files(c("C:/folder1", "C:/folder2"),
                          pattern="*.rda$", full.names=TRUE, 
                          ignore.case=TRUE)
sapply(data.sources,load,.GlobalEnv)
sapply(file.sources,source,.GlobalEnv)

Notice also the use of $ at the end of the search pattern, to make sure it matches only, say, a .R at the end of a line, and the use of ignore.case in case some of the files are named, say, script.r.