R: Shell-style Tests on Files

file_test {utils} | R Documentation

## Shell-style Tests on Files

### Description

Utility for shell-style file tests.

### Usage

    file_test(op, x, y)

### Arguments

`op` | a character string specifying the test to be performed. Unary tests (only `x` is used) are `"-f"` (existence and not being a directory), `"-d"` (existence and directory) and `"-x"` (executable as a file or searchable as a directory). Binary tests are `"-nt"` (strictly newer than, using the modification dates) and `"-ot"` (strictly older than): in both cases the test is false unless both files exist.
`x, y` | character vectors giving file paths.

### Details

‘Existence’ here means being on the file system and accessible by the `stat` system call (or a 64-bit extension) – on a Unix-alike this requires execute permission on all of the directories in the path that leads to the file, but no permissions on the file itself.

For the meaning of `"-x"` on Windows see `file.access`.

### See Also

`file.exists` which only tests for existence (`test -e` on some systems) but not for not being a directory.

`file.path`, `file.info`

### Examples

    dir <- file.path(R.home(), "library", "stats")
    file_test("-d", dir)
    file_test("-nt", file.path(dir, "R"), file.path(dir, "demo"))

[Package utils version 3.5.1 Index]