% File src/library/base/man/unlink.Rd
% Part of the R package, http://www.R-project.org
% Copyright 1995-2009 R Core Development Team
% Distributed under GPL 2 or later

\name{unlink}
\title{Delete Files and Directories}
\usage{unlink(x, recursive = FALSE)}
\alias{unlink}
\arguments{
  \item{x}{a character vector with the names of the file(s) or
    directories to be deleted.
    Wildcards (normally \file{*} and \file{?}) are allowed.}
  \item{recursive}{logical. Should directories be deleted
    recursively?}
}
\description{
  \code{unlink} deletes the file(s) or directories specified by \code{x}.
}
\details{
  If \code{recursive = FALSE} directories are not deleted,
  not even empty ones.

#ifdef unix
  On most platforms \sQuote{file} includes symbolic links, fifos and sockets.
  Some earlier versions of \R would bot try to remove broken symbolic links.
#endif  
  
  Wildcard expansion is done by the internal code of
  \code{\link{Sys.glob}}. Wildcards never match a leading \file{.} in
  the filename, and files \file{.} and \file{..} will never be
  considered for deletion.
#ifdef unix
  Wildcards will only be expanded if the system supports it.  Most
  systems will support not only \file{*} and \file{?}) but character
  classes such as \file{[a-z]} (see the \code{man} pages for
  \code{glob}).  The metacharacters \code{* ? [} can occur in Unix
  filenames, and this makes it difficult to use \code{unlink} to delete
  such files (see  \code{\link{file.remove}}), although escaping the
  metacharacters by backslashes usually works.  If a
  metacharacter matches nothing it is considered as a literal character.

  \code{recursive = TRUE} is not supported on all platforms, and may be
  ignored, with a warning.
#endif
#ifdef Windows
  Character classes such as \file{[a-z]} are supported.  The
  metacharacter \code{[} can occur in Windows filenames, and this makes
  it difficult to use \code{unlink} to delete such files (see
  \code{\link{file.remove}}).  If a wildcard matches
  nothing it is considered as a literal character.

  Windows cannot remove the current working directory, nor any file
  which is open nor any directory containing such a file.
#endif
}
\value{
  \code{0} for success, \code{1} for failure.
  Not deleting a non-existent file is not a failure, nor is being unable
  to delete a directory if \code{recursive = FALSE}.  However, missing
  values in \code{x} result are regarded as failures.
}
\references{
  Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988)
  \emph{The New S Language}.
  Wadsworth & Brooks/Cole.
}
\seealso{
  \code{\link{file.remove}}.
}
%Examples: tempfile has an 'unlink' example
\keyword{file}
