archive

R bindings to libarchive http://www.libarchive.org. Supports many archives formats, including tar, ZIP, 7-zip, RAR, CAB. Also supports many filters such as gzip, bzip2, compress, lzma, xz and uuencoded files, among others.

archive provides interfaces to read and write connections into archives, as well as efficiently reading and writing archives directly to disk.

Installation

You can install archive from CRAN with:

# install.packages("archive")

Example

Single file archives

Use archive_read() and archive_write() to read and write single files to an archive. These files return connections, which can be passed to any R interface which can take a connection. Most base R file system functions use connections, as well as some packages like readr.

library(readr) # read_csv(), write_csv(), cols()

# Write a single dataset to zip
write_csv(mtcars, archive_write("mtcars.zip", "mtcars.csv"))

# Read the data back, by default the first file is read from the archive.
read_csv(archive_read("mtcars.zip"), col_types = cols())
#> # A tibble: 32 × 11
#>     mpg   cyl  disp    hp  drat    wt  qsec    vs    am  gear  carb
#>   <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
#> 1  21       6   160   110  3.9   2.62  16.5     0     1     4     4
#> 2  21       6   160   110  3.9   2.88  17.0     0     1     4     4
#> 3  22.8     4   108    93  3.85  2.32  18.6     1     1     4     1
#> 4  21.4     6   258   110  3.08  3.22  19.4     1     0     3     1
#> # … with 28 more rows

# Also supports things like archiving and compression together
# Write a single dataset to (gzip compressed) tar
write_csv(mtcars, archive_write("mtcars.tar.gz", "mtcars.csv", options = "compression-level=9"))

# Read the data back
read_csv(archive_read("mtcars.tar.gz"), col_types = cols())
#> # A tibble: 32 × 11
#>     mpg   cyl  disp    hp  drat    wt  qsec    vs    am  gear  carb
#>   <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
#> 1  21       6   160   110  3.9   2.62  16.5     0     1     4     4
#> 2  21       6   160   110  3.9   2.88  17.0     0     1     4     4
#> 3  22.8     4   108    93  3.85  2.32  18.6     1     1     4     1
#> 4  21.4     6   258   110  3.08  3.22  19.4     1     0     3     1
#> # … with 28 more rows

# Archive file sizes
file.size(c("mtcars.zip", "mtcars.tar.gz"))
#> [1] 742 648

Multi file archives

archive_write_files() is used to create a new archive from multiple files on disk.

# Write a few files to the temp directory
write_csv(iris, "iris.csv")
write_csv(mtcars, "mtcars.csv")
write_csv(airquality, "airquality.csv")

# Add them to a new archive
archive_write_files("data.tar.xz", c("iris.csv", "mtcars.csv", "airquality.csv"))

# View archive contents
a <- archive("data.tar.xz")
a
#> # A tibble: 3 × 3
#>   path            size date               
#>   <chr>          <int> <dttm>             
#> 1 iris.csv        3716 2021-11-29 18:09:35
#> 2 mtcars.csv      1281 2021-11-29 18:09:35
#> 3 airquality.csv  2890 2021-11-29 18:09:35

# By default `archive_read()` will read the first file from a multi-file archive.
read_csv(archive_read("data.tar.xz"), col_types = cols())
#> # A tibble: 150 × 5
#>   Sepal.Length Sepal.Width Petal.Length Petal.Width Species
#>          <dbl>       <dbl>        <dbl>       <dbl> <chr>  
#> 1          5.1         3.5          1.4         0.2 setosa 
#> 2          4.9         3            1.4         0.2 setosa 
#> 3          4.7         3.2          1.3         0.2 setosa 
#> 4          4.6         3.1          1.5         0.2 setosa 
#> # … with 146 more rows

# Use a number to read a different file
read_csv(archive_read("data.tar.xz", file = 2), col_types = cols())
#> # A tibble: 32 × 11
#>     mpg   cyl  disp    hp  drat    wt  qsec    vs    am  gear  carb
#>   <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
#> 1  21       6   160   110  3.9   2.62  16.5     0     1     4     4
#> 2  21       6   160   110  3.9   2.88  17.0     0     1     4     4
#> 3  22.8     4   108    93  3.85  2.32  18.6     1     1     4     1
#> 4  21.4     6   258   110  3.08  3.22  19.4     1     0     3     1
#> # … with 28 more rows

# Or a filename to read a specific file
read_csv(archive_read("data.tar.xz", file = "mtcars.csv"), col_types = cols())
#> # A tibble: 32 × 11
#>     mpg   cyl  disp    hp  drat    wt  qsec    vs    am  gear  carb
#>   <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
#> 1  21       6   160   110  3.9   2.62  16.5     0     1     4     4
#> 2  21       6   160   110  3.9   2.88  17.0     0     1     4     4
#> 3  22.8     4   108    93  3.85  2.32  18.6     1     1     4     1
#> 4  21.4     6   258   110  3.08  3.22  19.4     1     0     3     1
#> # … with 28 more rows

Regular files (with compression)

file_write() returns a connection to filtered by one or more compressions or encodings. file_read() reads a compressed file, automatically detecting the compression used.