R: Find Names of R System Files

system.file {base} | R Documentation

## Find Names of R System Files

### Description

Finds the full file names of files in packages etc.

### Usage

    system.file(..., package = "base", lib.loc = NULL,
                mustWork = FALSE)

### Arguments

`...` | character vectors, specifying subdirectory and file(s) within some package. The default, none, returns the root of the package. Wildcards are not supported.
`package` | a character string with the name of a single package. An error occurs if more than one package name is given.
`lib.loc` | a character vector with path names of R libraries. See ‘Details’ for the meaning of the default value of `NULL`.
`mustWork` | logical. If `TRUE`, an error is given if there are no matching files.

### Details

This checks the existence of the specified files with `file.exists`. So file paths are only returned if there are sufficient permissions to establish their existence.

The unnamed arguments in `...` are usually character strings, but if character vectors they are recycled to the same length.

This uses `find.package` to find the package, and hence with the default `lib.loc = NULL` looks first for attached packages then in each library listed in `.libPaths()`. Note that if a namespace is loaded but the package is not attached, this will look only on `.libPaths()`.

### Value

A character vector of positive length, containing the file paths that matched `...`, or the empty string, `""`, if none matched (unless `mustWork = TRUE`).

If matching the root of a package, there is no trailing separator.

`system.file()` with no arguments gives the root of the base package.

### See Also

`R.home` for the root directory of the R installation, `list.files`.

`Sys.glob` to find paths via wildcards.

### Examples

    system.file()                  # The root of the 'base' package
    system.file(package = "stats") # The root of package 'stats'
    system.file("INDEX")
    system.file("help", "AnIndex", package = "splines")

[Package base version 3.1.2 Index]