archive_write {archive} | R Documentation |
Create a writable connection to a file in an archive.
Description
Create a writable connection to a file in an archive.
Usage
archive_write(
archive,
file,
mode = "w",
format = NULL,
filter = NULL,
options = character()
)
Arguments
archive |
character(1) The archive filename or an archive object.
|
file |
character(1) || integer(1) The filename within the archive,
specified either by filename or by position.
|
mode |
character(1) A description of how to open the
connection (if it should be opened initially). See section
‘Modes’ in base::connections() for possible values.
|
format |
character(1) default: NULL The archive format, one of ‘7zip’, ‘cab’, ‘cpio’, ‘iso9660’, ‘lha’, ‘mtree’, ‘shar’, ‘rar’, ‘raw’, ‘tar’, ‘xar’, ‘zip’, ‘warc’.
Supported formats differ depending on the libarchive version and build.
|
filter |
character(1) default: NULL The archive filter, one of ‘none’, ‘gzip’, ‘bzip2’, ‘compress’, ‘lzma’, ‘xz’, ‘uuencode’, ‘lzip’, ‘lrzip’, ‘lzop’, ‘grzip’, ‘lz4’, ‘zstd’.
Supported filters differ depending on the libarchive version and build.
|
options |
character() default: character(0) Options to pass to the filter or format.
The list of available options are documented in
options can have one of the following forms:
-
option=value
The option/value pair will be provided to every module.
Modules that do not accept an option with this name will
ignore it.
-
option
The option will be provided to every module with a value
of "1".
-
!option
The option will be provided to every module with a NULL
value.
-
module:option=value , module:option , module:!option
As above, but the corresponding option and value will be
provided only to modules whose name matches module.
See read options for available read options
See write options for available write options
|
Details
If format
and filter
are NULL
, they will be set automatically based on
the file extension given in file
when writing and automatically detected
using
Robust automatic format detection
when reading.
For traditional zip archives archive_write()
creates a connection which
writes the data to the specified file directly. For other archive formats
the file size must be known when the archive is created, so the data is
first written to a scratch file on disk and then added to the archive. This
scratch file is automatically removed when writing is complete.
Value
An 'archive_write' connection to the file within the archive to be written.
Examples
# Archive format and filters can be set automatically from the file extensions.
f1 <- tempfile(fileext = ".tar.gz")
write.csv(mtcars, archive_write(f1, "mtcars.csv"))
archive(f1)
unlink(f1)
# They can also be specified explicitly
f2 <- tempfile()
write.csv(mtcars, archive_write(f2, "mtcars.csv", format = "tar", filter = "bzip2"))
archive(f2)
unlink(f2)
# You can also pass additional options to control things like compression level
f3 <- tempfile(fileext = ".tar.gz")
write.csv(mtcars, archive_write(f3, "mtcars.csv", options = "compression-level=2"))
archive(f3)
unlink(f3)
[Package
archive version 1.1.8
Index]