Comparison of fs functions, base R, and shell commands

Most of the functionality is fs can be approximated with functions in base R or in a command line shell. The table at the end of this vignette can be used as a translation aid between these three methods.

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

• Vectorization. All fs functions are vectorized, accepting multiple paths as input. Base functions are inconsistently vectorized.

• Predictable return values that always convey a path. All fs functions return a character vector of paths, a named integer or a logical vector, where the names give the paths. Base return values are more varied: they are often logical or contain error codes which require downstream processing.

• Explicit failure. If fs operations fail, they throw an error. Base functions tend to generate a warning and a system dependent error code. This makes it easy to miss a failure.

• UTF-8 all the things. fs functions always convert input paths to UTF-8 and return results as UTF-8. This gives you path encoding consistency across OSes. Base functions rely on the native system encoding.

• Naming convention. fs functions use a consistent naming convention. Because base R’s functions were gradually added over time there are a number of different conventions used (e.g. path.expand() vs normalizePath(); Sys.chmod() vs file.access()).

Directory functions

fs base shell
dir_ls("path") list.files("path") ls path
dir_info("path") do.call(rbind, lapply(list.files("path"), file.info)) ls -al path
dir_copy("path", "new-path") dir.create("new-path"); file.copy("path", "new-path", recursive=TRUE) cp path new-path
dir_create("path") dir.create("path") mkdir path
dir_delete("path") unlink("path", recursive = TRUE) rm -rf path
dir_exists("path") dir.exists("path") if [ -d "path" ]; then ... ; fi
dir_move() (see file_move) file.rename("path", "new-path") mv path new-path
dir_map("path", fun) No direct equivalent for file in $(ls path); do ...; done dir_tree("path") No direct equivalent tree path File functions fs base shell file_chmod("path", "mode") Sys.chmod("path", "mode") chmod mode path file_chown("path", "user_id", "group_id") No direct equivalent chown options path file_copy("path", "new-path") file.copy("path", "new-path") cp path new-path file_create("new-path") file.create("new-path") touch new-path file_delete("path") unlink("path") rm path file_exists("path") file.exists("path") if [ -f "path" ]; then ... ; fi file_info("path") file.info("path") ls -al path file_move("path", "new-path") file.rename("path", "new-path") mv path new-path file_show("path") browseURL("path") open path file_touch() No direct equivalent touch path file_temp() tempfile() mktemp file_test() No direct equivalent if [ -d "path" ]; then ...; fi Path functions fs base shell path("top_dir", "nested_dir", "file", ext = "ext") file.path("top_dir", "nested_dir", "file.ext") top_dir/nested_dir/file.ext path_temp(), path_temp("path") tempdir(), file.path(tempdir(), "path") mktemp -d path_expand("~/path") path.expand() realpath -m -s ~/path path_dir("path") dirname("path") dirname path path_file("path") basename("path") basename path path_home() path.expand("~") $HOME
path_package("pkgname", "dir", "file") system.file("dir", "file", package = "pkgname") No direct equivalent
path_norm("path") normalizePath() realpath
path_real("path") normalizePath(mustWork = TRUE) realpath
path_rel("path/foo", "path/bar") No direct equivalent No direct equivalent
path_common(c("path/foo", "path/bar", "path/baz")) No direct equivalent No direct equivalent
path_ext_remove("path") sub("\\.[a-zA-Z0-9]*$", "", "path") No direct equivalent path_ext_set("path", "new_ext") sub("\\.[a-zA-Z0-9]*$", "new_ext", "path") No direct equivalent
path_sanitize("path") No direct equivalent No direct equivalent