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), "-L" or "-h" (existence and symbolic link), "-x" (executable as a file or searchable as a directory), "-w" (writable) and "-r" (readable). 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"))

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