compressFile.RdCompressing and decompressing files such as gzip:ed and bzip2:ed files.
NOTE: The default (remove=TRUE) behavior is that
the input file is removed after that the output file
is fully created and closed.
# S3 method for default
compressFile(filename, destname=sprintf("%s.%s", filename, ext), ext, FUN,
temporary=FALSE, skip=FALSE, overwrite=FALSE, remove=TRUE, BFR.SIZE=1e+07, ...)
# S3 method for default
decompressFile(filename, destname=gsub(sprintf("[.]%s$", ext), "", filename,
ignore.case = TRUE), ext, FUN, temporary=FALSE, skip=FALSE, overwrite=FALSE,
remove=TRUE, BFR.SIZE=1e+07, ...)
# S3 method for default
isCompressedFile(filename, method=c("extension", "content"), ext, fileClass, ...)
# S3 method for default
bzip2(filename, ..., ext="bz2", FUN=bzfile)
# S3 method for default
bunzip2(filename, ..., ext="bz2", FUN=bzfile)
# S3 method for default
gzip(filename, ..., ext="gz", FUN=gzfile)
# S3 method for default
gunzip(filename, ..., ext="gz", FUN=gzfile)Pathname of input file.
Pathname of output file.
If TRUE, the output file is created in a
temporary directory.
If TRUE and the output file already exists,
the output file is returned as is.
If TRUE and the output file already exists,
the file is silently overwritten, otherwise an exception is
thrown (unless skip is TRUE).
If TRUE, the input file is removed afterward,
otherwise not.
The number of bytes read in each chunk.
Passed to the underlying function or alternatively not used.
A character string specifying how to infer whether
a file is compressed or not.
(internal) Filename extension, file class,
and a connection function used to read from/write to file.
Returns the pathname of the output file. The number of bytes processed is returned as an attribute.
isCompressedFile(), isGzipped() and isBzipped()
return a logical.
Note that with method = "extension" (default), only the filename
extension is used to infer whether the file is compressed or not.
Specifically, it does not matter whether the file actually exists or not.
Internally bzfile() and gzfile()
(see connections) are used to read (write) files.
If the process is interrupted before completed, the partially written
output file is automatically removed.
## bzip2
cat(file="foo.txt", "Hello world!")
print(isBzipped("foo.txt"))
#> [1] FALSE
print(isBzipped("foo.txt.bz2"))
#> [1] TRUE
bzip2("foo.txt")
print(file.info("foo.txt.bz2"))
#> size isdir mode mtime ctime
#> foo.txt.bz2 51 FALSE 664 2023-11-17 17:03:35 2023-11-17 17:03:35
#> atime uid gid uname grname
#> foo.txt.bz2 2023-11-17 17:03:35 1000 1000 henrik henrik
print(isBzipped("foo.txt"))
#> [1] FALSE
print(isBzipped("foo.txt.bz2"))
#> [1] TRUE
bunzip2("foo.txt.bz2")
print(file.info("foo.txt"))
#> size isdir mode mtime ctime
#> foo.txt 12 FALSE 664 2023-11-17 17:03:35 2023-11-17 17:03:35
#> atime uid gid uname grname
#> foo.txt 2023-11-17 17:03:35 1000 1000 henrik henrik
## gzip
cat(file="foo.txt", "Hello world!")
print(isGzipped("foo.txt"))
#> [1] FALSE
print(isGzipped("foo.txt.gz"))
#> [1] TRUE
gzip("foo.txt")
print(file.info("foo.txt.gz"))
#> size isdir mode mtime ctime
#> foo.txt.gz 32 FALSE 664 2023-11-17 17:03:35 2023-11-17 17:03:35
#> atime uid gid uname grname
#> foo.txt.gz 2023-11-17 17:03:35 1000 1000 henrik henrik
print(isGzipped("foo.txt"))
#> [1] FALSE
print(isGzipped("foo.txt.gz"))
#> [1] TRUE
gunzip("foo.txt.gz")
print(file.info("foo.txt"))
#> size isdir mode mtime ctime
#> foo.txt 12 FALSE 664 2023-11-17 17:03:35 2023-11-17 17:03:35
#> atime uid gid uname grname
#> foo.txt 2023-11-17 17:03:35 1000 1000 henrik henrik
## Cleanup
file.remove("foo.txt")
#> [1] TRUE