Comparison of fs functions, base R, and shell commands • fs

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_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