Get a system file or directory

Get system files or directories, in R subdirectories, in package subdirectories, or elsewhere on the disk (including executables that are accessible on the search path).

system_file(..., exec = FALSE, package = NULL, lib.loc = NULL)

system_dir(..., exec = FALSE, package = NULL, lib.loc = NULL)

systemFile(..., exec = FALSE, package = NULL, lib.loc = NULL)

systemDir(..., exec = FALSE, package = NULL, lib.loc = NULL)

Arguments

...

One or several executables if exec = TRUE, or subpath to a file or dir in a package directory if package != NULL, or a list of paths and subpaths for testing the existence of a file on disk, or a list of directory components to retrieve in 'temp', 'sysTemp', 'user', 'home', 'bin', 'doc', 'etc' and/or 'share' to retrieve special system directories.

exec

If TRUE (default) search for executables on the search path. It supersedes all other arguments.

package

The name of one package to look for files or subdirs in its main directory (use exec = FALSE to search inside package dirs).

lib.loc

A character vector with path names of R libraries or NULL (search all currently known libraries in this case).

Value

A string with the path to the directories or files, or "" if they are not found, or of the wrong type (a dir for system_file() or or a file for system_dir()).

Note

These function aggregate the features of several R functions in package base: system.file(), R.home(), tempdir(), Sys.which(), and aims to provide a unified and convenient single interface to all of them. We make sure also to check that returned components are respectively directories and files for system_dir() and system_file().

See also

file_edit(), file.path(), file.exists()

Examples

system_file("INDEX", package = "base")
#> [1] "/opt/R/4.4.2/lib/R/library/base/INDEX"
system_file("help", "AnIndex", package = "splines")
#> [1] "/opt/R/4.4.2/lib/R/library/splines/help/AnIndex"
system_file(package = "base")  # This is a dir, not a file!
#> [1] ""
system_file("zip", exec = TRUE)
#> [1] "/usr/bin/zip"
system_file("ftp", "ping", "zip", "nonexistingexe", exec = TRUE)
#>             ftp            ping             zip  nonexistingexe 
#>  "/usr/bin/ftp" "/usr/bin/ping"  "/usr/bin/zip"              "" 
system_dir("temp")             # The R temporary directory
#> [1] "/tmp/RtmpTkCdbT"
system_dir("sysTemp")          # The system temporary directory
#> [1] "/tmp"
system_dir("user")             # The user directory
#> [1] "/home/runner"
system_dir("home", "bin", "doc", "etc", "share")  # Various R dirs
#>                       home                        bin 
#>       "/opt/R/4.4.2/lib/R"   "/opt/R/4.4.2/lib/R/bin" 
#>                        doc                        etc 
#>   "/opt/R/4.4.2/lib/R/doc"   "/opt/R/4.4.2/lib/R/etc" 
#>                      share 
#> "/opt/R/4.4.2/lib/R/share" 
system_dir("zip", exec = TRUE) # Look for the dir of an executable
#> [1] "/usr/bin"
system_dir("ftp", "ping", "zip", "nonexistingexe", exec = TRUE)
#>            ftp           ping            zip nonexistingexe 
#>     "/usr/bin"     "/usr/bin"     "/usr/bin"             "" 
system_dir(package = "base")   # The root of the 'base' package
#> [1] "/opt/R/4.4.2/lib/R/library/base"
system_dir(package = "stats")  # The root of package 'stats'
#> [1] "/opt/R/4.4.2/lib/R/library/stats"
system_dir("INDEX", package = "stats") # This is a file, not a dir!
#> [1] ""
system_dir("help", package = "splines")
#> [1] "/opt/R/4.4.2/lib/R/library/splines/help"