fs

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fs provides a cross-platform, uniform interface to file system operations. It shares the same back-end component as nodejs, the libuv C library, which brings the benefit of extensive real-world use and rigorous cross-platform testing. The name, and some of the interface, is partially inspired by Rust’s fs module.

Installation

You can install the released version of fs from CRAN with:

install.packages("fs")

And the development version from GitHub with:

# install.packages("devtools")
devtools::install_github("r-lib/fs")

Comparison vs base equivalents

fs functions smooth over some of the idiosyncrasies of file handling with base R functions:

Tidy paths

fs functions always return ‘tidy’ paths. Tidy paths

Tidy paths are also coloured (if your terminal supports it) based on the file permissions and file type. This colouring can be customized or extended by setting the LS_COLORS environment variable, in the same output format as GNU dircolors.

Usage

fs functions are divided into four main categories:

Directories and links are special types of files, so file_ functions will generally also work when applied to a directory or link.

library(fs)

# Construct a path to a file with `path()`
path("foo", "bar", letters[1:3], ext = "txt")
#> foo/bar/a.txt foo/bar/b.txt foo/bar/c.txt

# list files in the current directory
dir_ls()
#> DESCRIPTION      LICENSE.md       NAMESPACE        NEWS.md          
#> R                README.Rmd       README.md        _pkgdown.yml     
#> a                appveyor.yml     b                c                
#> codecov.yml      cran-comments.md docs             fs.Rproj         
#> fs_1.2.7.tar.gz  inst             man              man-roxygen      
#> revdep           script.R         src              tests            
#> top1             top2             vignettes

# create a new directory
tmp <- dir_create(file_temp())
tmp
#> /var/folders/dt/r5s12t392tb5sk181j3gs4zw0000gn/T/RtmpQMfPEs/file952a698992af

# create new files in that directory
file_create(path(tmp, "my-file.txt"))
dir_ls(tmp)
#> /var/folders/dt/r5s12t392tb5sk181j3gs4zw0000gn/T/RtmpQMfPEs/file952a698992af/my-file.txt

# remove files from the directory
file_delete(path(tmp, "my-file.txt"))
dir_ls(tmp)
#> character(0)

# remove the directory
dir_delete(tmp)

fs is designed to work well with the pipe, though because it is a minimal-dependency infrastructure package it doesn’t provide the pipe itself. You will need to attach magrittr or similar.

library(magrittr)
#> 
#> Attaching package: 'magrittr'
#> The following objects are masked from 'package:testthat':
#> 
#>     equals, is_less_than, not

paths <- file_temp() %>%
  dir_create() %>%
  path(letters[1:5]) %>%
  file_create()
paths
#> /var/folders/dt/r5s12t392tb5sk181j3gs4zw0000gn/T/RtmpQMfPEs/file952a21ea91af/a
#> /var/folders/dt/r5s12t392tb5sk181j3gs4zw0000gn/T/RtmpQMfPEs/file952a21ea91af/b
#> /var/folders/dt/r5s12t392tb5sk181j3gs4zw0000gn/T/RtmpQMfPEs/file952a21ea91af/c
#> /var/folders/dt/r5s12t392tb5sk181j3gs4zw0000gn/T/RtmpQMfPEs/file952a21ea91af/d
#> /var/folders/dt/r5s12t392tb5sk181j3gs4zw0000gn/T/RtmpQMfPEs/file952a21ea91af/e

paths %>% file_delete()

fs functions also work well in conjunction with other tidyverse packages, like dplyr and purrr.

Some examples…

suppressMessages(
  library(tidyverse))

Filter files by type, permission and size

dir_info("src", recursive = FALSE) %>%
  filter(type == "file", permissions == "u+r", size > "10KB") %>%
  arrange(desc(size)) %>%
  select(path, permissions, size, modification_time)
#> Warning: `recursive` is deprecated, please use `recurse` instead
#> # A tibble: 11 x 4
#>    path                permissions        size modification_time  
#>    <fs::path>          <fs::perms> <fs::bytes> <dttm>             
#>  1 src/RcppExports.o   rw-r--r--        874.8K 2019-04-02 14:24:08
#>  2 src/dir.o           rw-r--r--        493.9K 2019-04-02 14:24:08
#>  3 src/id.o            rw-r--r--        388.8K 2019-03-18 09:33:55
#>  4 src/fs.so           rwxr-xr-x        367.3K 2019-04-02 14:24:08
#>  5 src/file.o          rw-r--r--        358.7K 2019-03-18 10:10:35
#>  6 src/path.o          rw-r--r--        279.9K 2019-03-18 09:33:55
#>  7 src/link.o          rw-r--r--        227.7K 2019-03-18 09:33:55
#>  8 src/utils.o         rw-r--r--        127.2K 2019-03-18 11:29:09
#>  9 src/error.o         rw-r--r--         17.6K 2019-03-18 10:02:15
#> 10 src/RcppExports.cpp rw-r--r--         12.2K 2019-04-02 14:18:40
#> 11 src/file.cc         rw-r--r--         10.1K 2019-03-18 10:08:54

Tabulate and display folder size.

dir_info("src", recursive = TRUE) %>%
  group_by(directory = path_dir(path)) %>%
  tally(wt = size, sort = TRUE)
#> Warning: `recursive` is deprecated, please use `recurse` instead
#> # A tibble: 53 x 2
#>    directory                                        n
#>    <chr>                                  <fs::bytes>
#>  1 src                                          3.11M
#>  2 src/libuv                                    2.43M
#>  3 src/libuv/src/unix                            1.1M
#>  4 src/libuv/test                             865.35K
#>  5 src/libuv/src/win                          683.14K
#>  6 src/libuv/docs/src/static                   328.3K
#>  7 src/libuv/m4                               319.95K
#>  8 src/libuv/include                          192.33K
#>  9 src/libuv/docs/src/static/diagrams.key     184.02K
#> 10 src/libuv/src                              181.85K
#> # … with 43 more rows

Read a collection of files into one data frame.

dir_ls() returns a named vector, so it can be used directly with purrr::map_df(.id).

# Create separate files for each species
iris %>%
  split(.$Species) %>%
  map(select, -Species) %>%
  iwalk(~ write_tsv(.x, paste0(.y, ".tsv")))

# Show the files
iris_files <- dir_ls(glob = "*.tsv")
iris_files
#> setosa.tsv     versicolor.tsv virginica.tsv

# Read the data into a single table, including the filenames
iris_files %>%
  map_df(read_tsv, .id = "file", col_types = cols(), n_max = 2)
#> # A tibble: 6 x 5
#>   file           Sepal.Length Sepal.Width Petal.Length Petal.Width
#>   <chr>                 <dbl>       <dbl>        <dbl>       <dbl>
#> 1 setosa.tsv              5.1         3.5          1.4         0.2
#> 2 setosa.tsv              4.9         3            1.4         0.2
#> 3 versicolor.tsv          7           3.2          4.7         1.4
#> 4 versicolor.tsv          6.4         3.2          4.5         1.5
#> 5 virginica.tsv           6.3         3.3          6           2.5
#> 6 virginica.tsv           5.8         2.7          5.1         1.9

file_delete(iris_files)

Feedback wanted!

We hope fs is a useful tool for both analysis scripts and packages. Please open GitHub issues for any feature requests or bugs.

In particular, we have found non-ASCII filenames in non-English locales on Windows to be especially tricky to reproduce and handle correctly. Feedback from users who use commonly have this situation is greatly appreciated.