filelib
File utilities, such as wildcard matching of filenames
This module contains utilities on a higher level than the file
module.
DATA TYPES
filename() = string() | atom() | DeepList dirname() = filename() DeepList = [char() | atom() | DeepList]
Functions
ensure_dir(Name) -> ok | {error, Reason}
Name = filename() | dirname()
Reason = posix() -- see file(3)
The ensure_dir/1
function ensures that all parent
directories for the given file or directory name Name
exist, trying to create them if necessary.
Returns ok
if all parent directories already exist
or could be created, or {error, Reason}
if some parent
directory does not exist and could not be created for some
reason.
file_size(Filename) -> integer()
The file_size
function returns the size of the given file.
fold_files(Dir, RegExp, Recursive, Fun, AccIn) -> AccOut
Dir = dirname()
RegExp = regular_expression_string()
Recursive = true|false
Fun = fun(F, AccIn) -> AccOut
AccIn = AccOut = term()
The fold_files/5
function folds the function
Fun
over all (regular) files F
in the
directory Dir
that match the regular expression RegExp
(see the re module for a description
of the allowed regular expressions).
If Recursive
is true all sub-directories to Dir
are processed. The regular expression matching is done on just
the filename without the directory part.
is_dir(Name) -> true | false
Name = filename() | dirname()
The is_dir/1
function returns true
if Name
refers to a directory, and false
otherwise.
is_file(Name) -> true | false
Name = filename() | dirname()
The is_file/1
function returns true
if Name
refers to a file or a directory, and false
otherwise.
is_regular(Name) -> true | false
Name = filename()
The is_regular/1
function returns true
if Name
refers to a file (regular file), and false
otherwise.
last_modified(Name) -> {{Year,Month,Day},{Hour,Min,Sec}} | 0
Name = filename() | dirname()
The last_modified/1
function returns the date and time the
given file or directory was last modified, or 0 if the file
does not exist.
wildcard(Wildcard) -> list()
Wildcard = filename() | dirname()
The wildcard/1
function returns a list of all files
that match Unix-style wildcard-string Wildcard
.
The wildcard string looks like an ordinary filename, except that certain "wildcard characters" are interpreted in a special way. The following characters are special:
- ?
-
Matches one character.
- *
-
Matches any number of characters up to the end of the filename, the next dot, or the next slash.
- {Item,...}
-
Alternation. Matches one of the alternatives.
Other characters represent themselves. Only filenames that have exactly the same character in the same position will match. (Matching is case-sensitive; i.e. "a" will not match "A").
Note that multiple "*" characters are allowed (as in Unix wildcards, but opposed to Windows/DOS wildcards).
Examples:
The following examples assume that the current directory is the top of an Erlang/OTP installation.
To find all .beam
files in all applications, the following
line can be used:
filelib:wildcard("lib/*/ebin/*.beam").
To find either .erl
or .hrl
in all applications
src
directories, the following
filelib:wildcard("lib/*/src/*.?rl")
or the following line
filelib:wildcard("lib/*/src/*.{erl,hrl}")
can be used.
To find all .hrl
files in either src
or include
directories, use:
filelib:wildcard("lib/*/{src,include}/*.hrl").
To find all .erl
or .hrl
files in either
src
or include
directories, use:
filelib:wildcard("lib/*/{src,include}/*.{erl,hrl}")
wildcard(Wildcard, Cwd) -> list()
Wildcard = filename() | dirname()
Cwd = dirname()
The wildcard/2
function works like wildcard/1
,
except that instead of the actual working directory, Cwd
will be used.