tempfile returns a vector of character strings which can be used as names for temporary files.
tempfile(pattern = "file", tmpdir = tempdir(), fileext = "") tempdir()
- a non-empty character vector giving the initial part of the name.
- a non-empty character vector giving the directory name
- a non-empty character vector giving the file extension
The length of the result is the maximum of the lengths of the three arguments; values of shorter arguments are recycled.
The names are very likely to be unique among calls to
tempfile in an R session and across simultaneous R sessions (unless
tmpdir is specified). The filenames are guaranteed not to be currently in use.
The file name is made by concatenating the path given by
pattern string, a random string in hex and a suffix of
tmpdir will be the directory given by
tempdir(). This will be a subdirectory of the per-session temporary directory found by the following rule when the R session is started. The environment variables TMPDIR, TMP and TEMP are checked in turn and the first found which points to a writable directory is used: Note that setting any of these environment variables in the R session has no effect on
tempdir(): the per-session temporary directory is created before the interpreter is started.
tempdir, the path of the per-session temporary directory.
Note on parallel
R processes forked by functions such as
mclapply in package parallel (or multicore) share a per-session temporary directory. Further, the ‘guaranteed not to be currently in use’ applies only at the time of asking, and two children could ask simultaneously. As from R 2.14.1 this is avoided by ensuring that
tempfile calls in different children try different names.
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.
unlink for deleting files.
Documentation reproduced from R 3.0.1. License: GPL-2.