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%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Do not modify this file since it was automatically generated from:
%
% fileAccess.R
%
% by the Rdoc compiler part of the R.oo package.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\name{fileAccess}
\alias{fileAccess.default}
\alias{fileAccess}
\title{Checks the permission of a file or a directory}
\description{
Checks the permission of a file or a directory.
}
\usage{
\method{fileAccess}{default}(pathname, mode=0, safe=TRUE, ...)
}
\arguments{
\item{pathname}{A \code{\link[base]{character}} string of the file or the directory
to be checked.}
\item{mode}{An \code{\link[base]{integer}} (0,1,2,4), cf. \code{\link[base]{file.access}}().}
\item{safe}{If \code{\link[base:logical]{TRUE}}, the permissions are tested more carefully,
otherwise \code{\link[base]{file.access}}() is used.}
\item{...}{Not used.}
}
\value{
Returns an \code{\link[base]{integer}}; 0 if the permission exists, -1 if not.
}
\details{
In \R there is \code{\link[base]{file.access}}() for checking whether the
permission of a file.
Unfortunately, that function cannot be 100\% trusted depending on
platform used and file system queried, cf. [1].
}
\section{Symbolic links}{
This function follows symbolic links (also on Windows) and returns a
value based on the link target (rather than the link itself).
}
\examples{
# - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# Current directory
# - - - - - - - - - - - - - - - - - - - - - - - - - - - -
path <- "."
# Test for existence
print(fileAccess(path, mode=0))
# Test for execute permission
print(fileAccess(path, mode=1))
# Test for write permission
print(fileAccess(path, mode=2))
# Test for read permission
print(fileAccess(path, mode=4))
# - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# A temporary file
# - - - - - - - - - - - - - - - - - - - - - - - - - - - -
pathname <- tempfile()
cat(file=pathname, "Hello world!")
# Test for existence
print(fileAccess(pathname, mode=0))
# Test for execute permission
print(fileAccess(pathname, mode=1))
# Test for write permission
print(fileAccess(pathname, mode=2))
# Test for read permission
print(fileAccess(pathname, mode=4))
file.remove(pathname)
# - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# The 'base' package directory
# - - - - - - - - - - - - - - - - - - - - - - - - - - - -
path <- system.file(package="base")
# Test for existence
print(fileAccess(path, mode=0))
# Test for execute permission
print(fileAccess(path, mode=1))
# Test for write permission
print(fileAccess(path, mode=2))
# Test for read permission
print(fileAccess(path, mode=4))
# - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# The 'base' package DESCRIPTION file
# - - - - - - - - - - - - - - - - - - - - - - - - - - - -
pathname <- system.file("DESCRIPTION", package="base")
# Test for existence
print(fileAccess(pathname, mode=0))
# Test for execute permission
print(fileAccess(pathname, mode=1))
# Test for write permission
print(fileAccess(pathname, mode=2))
# Test for read permission
print(fileAccess(pathname, mode=4))
}
\seealso{
\code{\link[base]{file.access}}()
}
\references{
[1] R-devel thread
\emph{file.access() on network (mounted) drive on Windows Vista?}
on Nov 26, 2008.
\url{https://stat.ethz.ch/pipermail/r-devel/2008-December/051461.html}\cr
[2] Filesystem permissions, Wikipedia, 2010.
\url{https://en.wikipedia.org/wiki/Filesystem_permissions}\cr
}
\author{Henrik Bengtsson}
\keyword{IO}
\keyword{programming}
|
