1% File src/library/utils/man/filetest.Rd
2% Part of the R package, https://www.R-project.org
3% Copyright 1995-2009 R Core Team
4% Distributed under GPL 2 or later
5
6\name{file_test}
7\alias{file_test}
8\title{
9  Shell-style Tests on Files
10}
11\description{
12  Utility for shell-style file tests.
13}
14\usage{
15file_test(op, x, y)
16}
17\arguments{
18  \item{op}{a character string specifying the test to be performed.
19    Unary tests (only \code{x} is used) are \code{"-f"} (existence and
20    not being a directory), \code{"-d"} (existence and directory) and
21    \code{"-x"} (executable as a file or searchable as a directory).
22    Binary tests are \code{"-nt"} (strictly newer than, using the modification
23    dates) and \code{"-ot"} (strictly older than): in both cases the
24    test is false unless both files exist.}
25  \item{x, y}{character vectors giving file paths.}
26}
27\details{
28  \sQuote{Existence} here means being on the file system and accessible
29  by the \code{stat} system call (or a 64-bit extension) -- on a
30  Unix-alike this requires execute permission on all of the directories in
31  the path that leads to the file, but no permissions on the file
32  itself.
33
34  For the meaning of \code{"-x"} on Windows see \code{\link{file.access}}.
35}
36\seealso{
37  \code{\link{file.exists}} which only tests for existence
38  (\code{test -e} on some systems) but not for not being a directory.
39
40  \code{\link{file.path}}, \code{\link{file.info}}
41}
42\examples{
43dir <- file.path(R.home(), "library", "stats")
44file_test("-d", dir)
45file_test("-nt", file.path(dir, "R"), file.path(dir, "demo"))
46}
47\keyword{file}
48