The R Project SVN R

% File src/library/utils/man/unzip.Rd
% Part of the R package, http://www.R-project.org
% Copyright 1995-2011 R Core Development Team
% Distributed under GPL 2 or later

\name{unzip}
\alias{unzip}
\title{
  Extract or List Zip Archives
}
\description{
  Extract files from or list a zip archive.
}
\usage{
unzip(zipfile, files = NULL, list = FALSE, overwrite = TRUE,
       junkpaths = FALSE, exdir = ".", unzip = "internal")
}
\arguments{
  \item{zipfile}{The pathname of the zip file: tilde expansion (see
    \code{\link{path.expand}}) will be performed.}

  \item{files}{A character vector of recorded filepaths to be extracted:
    the default is to extract all files.}
  
  \item{list}{If \code{TRUE}, list the files and extract none.  The
    equivalent of \command{unzip -l}.}
  
  \item{overwrite}{If \code{TRUE}, overwrite existing files, otherwise
    ignore such files.  The equivalent of \command{unzip -o}.}
  
  \item{junkpaths}{If \code{TRUE}, use only the basename of the stored
    filepath when extracting.  The equivalent of \command{unzip -j}.}
  
  \item{exdir}{The directory to extract files to (the equivalent of
    \code{unzip -d}).  It will be created if necessary.}

  \item{unzip}{The method to be used. An alternative is to use
  \code{getOption("unzip"}), which on a Unix-alike may be set to the
  path to a \command{unzip} program.}
}
\note{
  This is a minimal implementation, principally designed for Windows'
  users to be able to unpack Windows binary packages without external
  software.  It does not (for example) support Unicode filenames and
  large files as introduced in \command{zip 3.0}: for that use
  \code{unzip = "unzip"} with \command{unzip 6.00} or later.

  If \code{unzip} specifies a program, the format of the dates listed
  with \code{list=TRUE} is unknown (on Windows it can even depend on
  the current locale) and the return values could be \code{NA} or
  expressed in the wrong timezone or misinterpreted (the latter being
  far less likely as from \command{unzip 6.00}).
}

\value{
  If \code{list = TRUE}, a data frame with columns \code{Name}
  (character) \code{Length} (the size of the uncompressed file, usually
  integer, conceivably numeric with an external \code{unzip}) and
  \code{Date} (of class \code{"\link{POSIXct}"}).

  Otherwise for the \code{"internal"} method, a character vector of the
  filepaths extracted to, invisibly.
}

\source{
  The internal C code uses \code{zlib} and is in particular based on the
  contributed \samp{minizip} application in the \code{zlib} sources
  (from \url{http://zlib.net}) by Gilles Vollant.
}

\seealso{
  \code{\link{unz}} to read a single component from a zip file.

  \code{\link{zip}}.
}

\keyword{file}
\keyword{utilities}