Temporary directory and files
Firstly let’s create a folder to work with in a temporary directory. Look for details on how to work with temporary files in R in my post When do you need temporary directory and files in R and how to use them.
tempfile() does not create any files, it generates a random file name, what is unique for the current R session. By default
tempfile() generates file name in R temporary directory.
Exploring file system
mydirname variable we have a file path where we can create a file. Now there is nothing. Let’s check it with function
file.exists() and the content of the temporary directory with function
Creating of a directory
Next we really touch our file system and create desired directory.
And check it again:
- content of parent directory;
- modification time.
More listings including R system files
Let’s inspect files from one of installed R-packages. A command
system.file() returns full path of files from installed packages. We use it to get a file path of
Next we list content of this folder.
We can check content of any subdir. For example “demo” folder.
In some situations you would prefer full names:
Constructing of file names in R
What is a file name? It is a character string. Wrong. It is a system-specific character string.
file.path() creates system-specific file names.
Note about Windows
file.path() put slashes as separator, when we used to backslash in Windows (for example
C:\Program Files\R\R-3.3.1)? There is even a special note on it in
file.path’s help page:
The components are by default separated by ‘/’ (not ‘\’) on Windows.
Surprisingly DOS and Windows supported slash as file path separator from the beginning. So in most cases one can use as slash, so backslash in Windows.comments powered by Disqus