Module fs

fs:get_temp_dir()
Return the name of the directory used for temporary files.
List of directories is searched to find one which the calling user can create files in. The list is:

The directory named by the TMPDIR environment variable.
The directory named by the TEMP environment variable.
The directory named by the TMP environment variable.
As a last resort, the current working directory.

fs:list_dir(path = ‘.’)
Return a list containing the names of the entries in the directory given by

path

.

fs:walk_dir(path = ‘.’, (String -> Bool) dir_filter = N, files_only = 1B)
Generate the file and directory names in a directory tree under

path

.
If

files_only

is true (1B), only file names are returned.
If

dir_filter

is given, then it is called for each directory and if

dir_filter

returns false (0B) for a specific directory, then

walk_dir

will not enter that directory.

fs:is_dir(path)
Return true (1B) if

path

is an existing directory (or a symbolic link pointing to a directory).

fs:is_file(path)
Return true (1B) if

path

is an existing file (or a symbolic link pointing to a file).
Why there is no fs:exists(path) function?

Because I think the intention should be expressed more clearly.
Consider this Python code:

if not os.path.isfile(out_fname) or os.stat(out_fname).st_mtime < os.stat(in_fname).st_mtime:
    open(out_fname, 'w').write(...)

If you replace

os.path.isfile

with

os.path.exists

then this code can work "ok" (i.e. silently works incorrectly) when

out_fname

is a directory, but with

isfile

the PermissionError is raised in line

open(out_fname, 'w').write(...)

.

So if you really want to check like

os.path.exists

in Python, use more verbose code in 11l:

fs:is_file(path) | fs:is_dir(path)

or:

path. {fs:is_file(.) | fs:is_dir(.)}

fs:is_symlink(path)
Return true (1B) if path refers to an existing symbolic link.

fs:file_size(path)
Return the size of the file, in bytes.

fs:create_dir(path)
Create a directory named

path

.

fs:create_dirs(path)
Recursive directory creation function. Like

create_dir()

, but creates all intermediate-level directories needed to contain the leaf directory.

fs:remove_file(path)
Remove (delete) the file

path

.

fs:remove_dir(path)
Remove (delete) the directory

path

. Only works when the directory is empty.

fs:remove_all(p)
Deletes the contents of

(if it is a directory) and the contents of all its subdirectories, recursively, then deletes p itself. Symlinks are not followed (symlink is removed, not its target).

fs:rename(old_p, new_p)
Moves or renames the filesystem object identified by

old_p

new_p

.

fs:path:sep
The character used by the operating system to separate pathname components. This is

for POSIX and

for Windows.

fs:path:join(path1, path2)
Join

path1

and

path2

.

fs:path:dir_name(path)
Return the directory name of pathname

path

(for example:

fs:path:dir_name(‘./a/b’)

‘./a’

).

fs:path:base_name(path)
Return the base name of pathname

path

(for example:

fs:path:base_name(‘./a/b’)

‘b’

).

fs:path:absolute(path)
Return an absolutized version of the pathname

path

.

fs:path:relative(path, base)
Return a relative filepath to

path

from a

base

directory.

fs:path:split_ext(path)
Split the pathname

path

into a pair

(root, ext)

such that

root‘’ext == path

, and

ext

is empty or begins with a period and contains at most one period.