R/file_read.R, R/file_write.R
file_connections.RdThey are functionally equivalent to calling archive_read or
archive_write using format = "raw", archive = file.
character(1) || integer(1) The filename within the archive,
specified either by filename or by position.
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.
character(1) default: NULL The archive filter, one of choices_rd(names(archive:::archive_filters())).
Supported filters differ depending on the libarchive version and build.
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
An 'archive_read' connection (for file_read()) or an 'archive_write' connection (for file_write()) to the file.
file_write() returns an writable output connection,
file_read() returns a readable input connection.
if (archive:::libarchive_version() > "3.2.0") {
# Write bzip2, base 64 encoded data and use high compression
write.csv(mtcars,
file_write("mtcars.bz2",
filter = c("uuencode", "bzip2"),
options = "compression-level=9"
)
)
# Read it back
read.csv(file_read("mtcars.bz2"), row.names = 1, nrows = 3)
unlink("mtcars.bz2")
}