Check in R if a Directory Exists and Create if It doesn’t (Programming Example)
This R tutorial explains how to check for the existence of a directory and create a new directory if it doesn’t exist.
The article contains the following sections:
- Store Working Directory
- Check for Existence of Sub-directory
- Create New Sub-directory
- Video Tutorial & Further Resources
Let’s dive right into the examples…
Store Working Directory
main_dir <- "C:/Users/ ... Your Path ... /main_dir" # Set your working directory
The previous R code stored our main working directory in the data object main_dir. Note that you have to replace the … Your Path … with your own directory path.
Let’s have a look on our example directory:
Figure 1: Example Directory with One Already Existing Sub-directory.
As you can see based on Figure 1, our example directory contains one sub-directory with the name subdir_example.
Check for Existence of Sub-directory
In this section, we will try to create a new directory, but only in case the directory name does not exist yet. First, we need to specify the name of the sub-directory that we want to create. Let’s assume that we want to create the folder subdir_example (i.e. a folder with the same name as the folder that already exists).
sub_dir_exists <- "subdir_example" # Name of already existing folder
With the following R code, we can check for the existence of this directory and create it in case it doesn’t exist:
dir.create(file.path(main_dir, sub_dir_exists)) # Try to create already existing folder # Warning message: # In dir.create(file.path(main_dir, sub_dir_exists)) : # 'C:\Users\ ... Your Path ... \main_dir\subdir_example' already exists
The RStudio console returns a warning message:
In dir.create(file.path(main_dir, sub_dir_exists)) :
‘C:\Users\ … Your Path … \main_dir\subdir_example’ already exists
If you see this warning message, you know that a file with your specified name already exists and that no new folder was created.
Create New Sub-directory
If we want to create a new sub-directory, we need to specify a new name that does not exist yet:
sub_dir_new <- "subdir_new" # Name of new folder
Now, we can apply exactly the same R syntax as in the previous section…
dir.create(file.path(main_dir, sub_dir_new)) # Create new folder
…but this time we do not get a warning – The new folder was successfully created:
Figure 2: Example Directory with New Sub-directory.
Video Tutorial & Further Resources
On my YouTube channel, I have published a live programming tutorial, which contains the examples of this article. In case you are interested, you can find the video tutorial below:
Also, you might want to have a look at the other R tutorials of this homepage. You can find some recommended tutorial below:
This page explained how to create a directory in RStudio in case it does not exist yet. If you have any further questions, please let me know in the comments below.