| zip.file.extract {utils} | R Documentation |
Extract File from a Zip Archive
Description
This will extract the file named file from the zip archive,
if possible, and write it in a temporary location.
Usage
zip.file.extract(file, zipname = "R.zip",
unzip = getOption("unzip"), dir = tempdir())
Arguments
file |
file name. (If a path is given, see ‘Note’.) |
zipname |
The file name (not path) of a |
unzip |
character string: the method to be used, an empty string
indicates |
dir |
directory (“folder”) name into which the extraction happens. Must be writable to the caller. |
Details
All platforms support an "internal" unzip: this is the default
under Windows and the fall-back under Unix if no unzip program
was found during configuration and R_UNZIPCMD is not set.
The file will be extracted if it is in the archive and any required
unzip utility is available. It will be extracted to the
directory given by dir, overwriting any existing file of
that name.
Value
The name of the original or extracted file. Success is indicated by returning a different name.
Note
The "internal" method is very simple, and will not set file dates.
This is a helper function for help,
example and data. As such, it handles
file paths in an unusual way. Any path component of zipname is
ignored, and the path to file is used only to determine the
directory within which to find zipname.
Source
The C code uses zlib and is in particular based on the
contributed ‘minizip’ application in the zlib sources by
Gilles Vollant.
See Also
unzip