Objects of class Dir are directory streams representing directories in the underlying file system. They provide a variety of ways to list directories and their contents. See also File.

The directory used in these examples contains the two regular files (config.h and main.rb), the parent directory (..), and the directory itself (.).

Methods
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Included Modules
Class Public methods
Dir[ string [, string ...] ] → array

Equivalent to calling Dir.glob([string,...],0).

static VALUE
dir_s_aref(int argc, VALUE *argv, VALUE obj)
{
    if (argc == 1) {
        return rb_push_glob(argv[0], 0);
    }
    return dir_globs(argc, argv, 0);
}
Dir.chdir( [ string] ) → 0
Dir.chdir( [ string] ) {| path | block } → anObject

Changes the current working directory of the process to the given string. When called without an argument, changes the directory to the value of the environment variable HOME, or LOGDIR. SystemCallError (probably Errno::ENOENT) if the target directory does not exist.

If a block is given, it is passed the name of the new current directory, and the block is executed with that as the current directory. The original working directory is restored when the block exits. The return value of chdir is the value of the block. chdir blocks can be nested, but in a multi-threaded program an error will be raised if a thread attempts to open a chdir block while another thread has one open.

Dir.chdir("/var/spool/mail")
puts Dir.pwd
Dir.chdir("/tmp") do
  puts Dir.pwd
  Dir.chdir("/usr") do
    puts Dir.pwd
  end
  puts Dir.pwd
end
puts Dir.pwd

produces:

/var/spool/mail
/tmp
/usr
/tmp
/var/spool/mail
static VALUE
dir_s_chdir(int argc, VALUE *argv, VALUE obj)
{
    VALUE path = Qnil;

    rb_secure(2);
    if (rb_scan_args(argc, argv, "01", &path) == 1) {
        FilePathValue(path);
        path = rb_str_encode_ospath(path);
    }
    else {
        const char *dist = getenv("HOME");
        if (!dist) {
            dist = getenv("LOGDIR");
            if (!dist) rb_raise(rb_eArgError, "HOME/LOGDIR not set");
        }
        path = rb_str_new2(dist);
    }

    if (chdir_blocking > 0) {
        if (!rb_block_given_p() || rb_thread_current() != chdir_thread)
            rb_warn("conflicting chdir during another chdir block");
    }

    if (rb_block_given_p()) {
        struct chdir_data args;

        args.old_path = rb_str_encode_ospath(rb_dir_getwd());
        args.new_path = path;
        args.done = FALSE;
        return rb_ensure(chdir_yield, (VALUE)&args, chdir_restore, (VALUE)&args);
    }
    dir_chdir(path);

    return INT2FIX(0);
}
Dir.chroot( string ) → 0

Changes this process's idea of the file system root. Only a privileged process may make this call. Not available on all platforms. On Unix systems, see chroot(2) for more information.

static VALUE
dir_s_chroot(VALUE dir, VALUE path)
{
    check_dirname(&path);
    if (chroot(RSTRING_PTR(path)) == -1)
        rb_sys_fail_path(path);

    return INT2FIX(0);
}
Dir.delete( string ) → 0

Deletes the named directory. Raises a subclass of SystemCallError if the directory isn't empty.

static VALUE
dir_s_rmdir(VALUE obj, VALUE dir)
{
    check_dirname(&dir);
    if (rmdir(RSTRING_PTR(dir)) < 0)
        rb_sys_fail_path(dir);

    return INT2FIX(0);
}
Dir.entries( dirname ) → array
Dir.entries( dirname, encoding: enc ) → array

Returns an array containing all of the filenames in the given directory. Will raise a SystemCallError if the named directory doesn't exist.

The optional enc argument specifies the encoding of the directory. If not specified, the filesystem encoding is used.

Dir.entries("testdir")   #=> [".", "..", "config.h", "main.rb"]
static VALUE
dir_entries(int argc, VALUE *argv, VALUE io)
{
    VALUE dir;

    dir = dir_open_dir(argc, argv);
    return rb_ensure(rb_Array, dir, dir_close, dir);
}
Dir.exist?(file_name) → true or false
Dir.exists?(file_name) → true or false

Returns true if the named file is a directory, false otherwise.

VALUE
rb_file_directory_p()
{
}
exists?(p1)
static VALUE
rb_dir_exists_p(VALUE obj, VALUE fname)
{
    rb_warning("Dir.exists? is a deprecated name, use Dir.exist? instead");
    return rb_file_directory_p(obj, fname);
}
Dir.foreach( dirname ) {| filename | block } → nil
Dir.foreach( dirname, encoding: enc ) {| filename | block } → nil
Dir.foreach( dirname ) → an_enumerator
Dir.foreach( dirname, encoding: enc ) → an_enumerator

Calls the block once for each entry in the named directory, passing the filename of each entry as a parameter to the block.

If no block is given, an enumerator is returned instead.

Dir.foreach("testdir") {|x| puts "Got #{x}" }

produces:

Got .
Got ..
Got config.h
Got main.rb
static VALUE
dir_foreach(int argc, VALUE *argv, VALUE io)
{
    VALUE dir;

    RETURN_ENUMERATOR(io, argc, argv);
    dir = dir_open_dir(argc, argv);
    rb_ensure(dir_each, dir, dir_close, dir);
    return Qnil;
}
Dir.getwd → string

Returns the path to the current working directory of this process as a string.

Dir.chdir("/tmp")   #=> 0
Dir.getwd           #=> "/tmp"
static VALUE
dir_s_getwd(VALUE dir)
{
    return rb_dir_getwd();
}
Dir.glob( pattern, [flags] ) → matches
Dir.glob( pattern, [flags] ) { |filename| block } → nil

Expands pattern, which is an Array of patterns or a pattern String, and returns the results as matches or as arguments given to the block.

Note that this pattern is not a regexp, it's closer to a shell glob. See File.fnmatch for the meaning of the flags parameter. Note that case sensitivity depends on your system (so File::FNM_CASEFOLD is ignored), as does the order in which the results are returned.

*

Matches any file. Can be restricted by other values in the glob. Equivalent to / .* /x in regexp.

*

Matches all files

c*

Matches all files beginning with c

*c

Matches all files ending with c

*c*

Match all files that have c in them (including at the beginning or end).

Note, this will not match Unix-like hidden files (dotfiles). In order to include those in the match results, you must use the File::FNM_DOTMATCH flag or something like "{*,.*}".

**

Matches directories recursively.

?

Matches any one character. Equivalent to /.{1}/ in regexp.

[set]

Matches any one character in set. Behaves exactly like character sets in Regexp, including set negation ([^a-z]).

{p,q}

Matches either literal p or literal q. Equivalent to pattern alternation in regexp.

Matching literals may be more than one character in length. More than two literals may be specified.

\

Escapes the next metacharacter.

Note that this means you cannot use backslash on windows as part of a glob, i.e. Dir["c:\foo*"] will not work, use Dir["c:/foo*"] instead.

Examples:

Dir["config.?"]                     #=> ["config.h"]
Dir.glob("config.?")                #=> ["config.h"]
Dir.glob("*.[a-z][a-z]")            #=> ["main.rb"]
Dir.glob("*.[^r]*")                 #=> ["config.h"]
Dir.glob("*.{rb,h}")                #=> ["main.rb", "config.h"]
Dir.glob("*")                       #=> ["config.h", "main.rb"]
Dir.glob("*", File::FNM_DOTMATCH)   #=> [".", "..", "config.h", "main.rb"]

rbfiles = File.join("**", "*.rb")
Dir.glob(rbfiles)                   #=> ["main.rb",
                                    #    "lib/song.rb",
                                    #    "lib/song/karaoke.rb"]
libdirs = File.join("**", "lib")
Dir.glob(libdirs)                   #=> ["lib"]

librbfiles = File.join("**", "lib", "**", "*.rb")
Dir.glob(librbfiles)                #=> ["lib/song.rb",
                                    #    "lib/song/karaoke.rb"]

librbfiles = File.join("**", "lib", "*.rb")
Dir.glob(librbfiles)                #=> ["lib/song.rb"]
static VALUE
dir_s_glob(int argc, VALUE *argv, VALUE obj)
{
    VALUE str, rflags, ary;
    int flags;

    if (rb_scan_args(argc, argv, "11", &str, &rflags) == 2)
        flags = NUM2INT(rflags);
    else
        flags = 0;

    ary = rb_check_array_type(str);
    if (NIL_P(ary)) {
        ary = rb_push_glob(str, flags);
    }
    else {
        volatile VALUE v = ary;
        ary = dir_globs(RARRAY_LEN(v), RARRAY_CONST_PTR(v), flags);
    }

    if (rb_block_given_p()) {
        rb_ary_each(ary);
        return Qnil;
    }
    return ary;
}
Dir.home() → "/home/me"
Dir.home("root") → "/root"

Returns the home directory of the current user or the named user if given.

static VALUE
dir_s_home(int argc, VALUE *argv, VALUE obj)
{
    VALUE user;
    const char *u = 0;

    rb_check_arity(argc, 0, 1);
    user = (argc > 0) ? argv[0] : Qnil;
    if (!NIL_P(user)) {
        SafeStringValue(user);
        rb_must_asciicompat(user);
        u = StringValueCStr(user);
        if (*u) {
            return rb_home_dir_of(user, rb_str_new(0, 0));
        }
    }
    return rb_default_home_dir(rb_str_new(0, 0));

}
Dir.mkdir( string [, integer] ) → 0

Makes a new directory named by string, with permissions specified by the optional parameter anInteger. The permissions may be modified by the value of File::umask, and are ignored on NT. Raises a SystemCallError if the directory cannot be created. See also the discussion of permissions in the class documentation for File.

Dir.mkdir(File.join(Dir.home, ".foo"), 0700) #=> 0
static VALUE
dir_s_mkdir(int argc, VALUE *argv, VALUE obj)
{
    VALUE path, vmode;
    int mode;

    if (rb_scan_args(argc, argv, "11", &path, &vmode) == 2) {
        mode = NUM2INT(vmode);
    }
    else {
        mode = 0777;
    }

    check_dirname(&path);
    if (mkdir(RSTRING_PTR(path), mode) == -1)
        rb_sys_fail_path(path);

    return INT2FIX(0);
}
mktmpdir(prefix_suffix=nil, *rest)

::mktmpdir creates a temporary directory.

The directory is created with 0700 permission. Application should not change the permission to make the temporary directory accessible from other users.

The prefix and suffix of the name of the directory is specified by the optional first argument, prefix_suffix.

  • If it is not specified or nil, ā€œdā€ is used as the prefix and no suffix is used.

  • If it is a string, it is used as the prefix and no suffix is used.

  • If it is an array, first element is used as the prefix and second element is used as a suffix.

Dir.mktmpdir {|dir| dir is ".../d..." }
Dir.mktmpdir("foo") {|dir| dir is ".../foo..." }
Dir.mktmpdir(["foo", "bar"]) {|dir| dir is ".../foo...bar" }

The directory is created under ::tmpdir or the optional second argument tmpdir if non-nil value is given.

Dir.mktmpdir {|dir| dir is "#{Dir.tmpdir}/d..." }
Dir.mktmpdir(nil, "/var/tmp") {|dir| dir is "/var/tmp/d..." }

If a block is given, it is yielded with the path of the directory. The directory and its contents are removed using FileUtils.remove_entry before ::mktmpdir returns. The value of the block is returned.

Dir.mktmpdir {|dir|
  # use the directory...
  open("#{dir}/foo", "w") { ... }
}

If a block is not given, The path of the directory is returned. In this case, ::mktmpdir doesn't remove the directory.

dir = Dir.mktmpdir
begin
  # use the directory...
  open("#{dir}/foo", "w") { ... }
ensure
  # remove the directory.
  FileUtils.remove_entry dir
end
# File lib/tmpdir.rb, line 84
def Dir.mktmpdir(prefix_suffix=nil, *rest)
  path = Tmpname.create(prefix_suffix || "d", *rest) {|n| mkdir(n, 0700)}
  if block_given?
    begin
      yield path
    ensure
      stat = File.stat(File.dirname(path))
      if stat.world_writable? and !stat.sticky?
        raise ArgumentError, "parent directory is world writable but not sticky"
      end
      FileUtils.remove_entry path
    end
  else
    path
  end
end
Dir.new( string ) → aDir
Dir.new( string, encoding: enc ) → aDir

Returns a new directory object for the named directory.

The optional enc argument specifies the encoding of the directory. If not specified, the filesystem encoding is used.

static VALUE
dir_initialize(int argc, VALUE *argv, VALUE dir)
{
    struct dir_data *dp;
    rb_encoding  *fsenc;
    VALUE dirname, opt, orig;
    static ID keyword_ids[1];

    if (!keyword_ids[0]) {
        keyword_ids[0] = rb_intern("encoding");
    }

    fsenc = rb_filesystem_encoding();

    rb_scan_args(argc, argv, "1:", &dirname, &opt);

    if (!NIL_P(opt)) {
        VALUE enc;
        rb_get_kwargs(opt, keyword_ids, 0, 1, &enc);
        if (enc != Qundef && !NIL_P(enc)) {
            fsenc = rb_to_encoding(enc);
        }
    }

    GlobPathValue(dirname, FALSE);
    orig = rb_str_dup_frozen(dirname);
    dirname = rb_str_encode_ospath(dirname);
    dirname = rb_str_dup_frozen(dirname);

    TypedData_Get_Struct(dir, struct dir_data, &dir_data_type, dp);
    if (dp->dir) closedir(dp->dir);
    dp->dir = NULL;
    dp->path = Qnil;
    dp->enc = fsenc;
    dp->dir = opendir(RSTRING_PTR(dirname));
    if (dp->dir == NULL) {
        if (errno == EMFILE || errno == ENFILE) {
            rb_gc();
            dp->dir = opendir(RSTRING_PTR(dirname));
        }
        if (dp->dir == NULL) {
            rb_sys_fail_path(orig);
        }
    }
    dp->path = orig;

    return dir;
}
Dir.open( string ) → aDir
Dir.open( string, encoding: enc ) → aDir
Dir.open( string ) {| aDir | block } → anObject
Dir.open( string, encoding: enc ) {| aDir | block } → anObject

The optional enc argument specifies the encoding of the directory. If not specified, the filesystem encoding is used.

With no block, open is a synonym for Dir::new. If a block is present, it is passed aDir as a parameter. The directory is closed at the end of the block, and Dir::open returns the value of the block.

static VALUE
dir_s_open(int argc, VALUE *argv, VALUE klass)
{
    struct dir_data *dp;
    VALUE dir = TypedData_Make_Struct(klass, struct dir_data, &dir_data_type, dp);

    dir_initialize(argc, argv, dir);
    if (rb_block_given_p()) {
        return rb_ensure(rb_yield, dir, dir_close, dir);
    }

    return dir;
}
Dir.pwd → string

Returns the path to the current working directory of this process as a string.

Dir.chdir("/tmp")   #=> 0
Dir.getwd           #=> "/tmp"
static VALUE
dir_s_getwd(VALUE dir)
{
    return rb_dir_getwd();
}
Dir.rmdir( string ) → 0

Deletes the named directory. Raises a subclass of SystemCallError if the directory isn't empty.

static VALUE
dir_s_rmdir(VALUE obj, VALUE dir)
{
    check_dirname(&dir);
    if (rmdir(RSTRING_PTR(dir)) < 0)
        rb_sys_fail_path(dir);

    return INT2FIX(0);
}
tmpdir()

Returns the operating system's temporary file path.

# File lib/tmpdir.rb, line 20
def Dir::tmpdir
  if $SAFE > 0
    tmp = @@systmpdir
  else
    tmp = nil
    for dir in [ENV['TMPDIR'], ENV['TMP'], ENV['TEMP'], @@systmpdir, '/tmp', '.']
      next if !dir
      dir = File.expand_path(dir)
      if stat = File.stat(dir) and stat.directory? and stat.writable? and
          (!stat.world_writable? or stat.sticky?)
        tmp = dir
        break
      end rescue nil
    end
    raise ArgumentError, "could not find a temporary directory" if !tmp
    tmp
  end
end

Deletes the named directory. Raises a subclass of SystemCallError if the directory isn't empty.

Instance Public methods
dir.close → nil

Closes the directory stream. Any further attempts to access dir will raise an IOError.

d = Dir.new("testdir")
d.close   #=> nil
static VALUE
dir_close(VALUE dir)
{
    struct dir_data *dirp;

    GetDIR(dir, dirp);
    closedir(dirp->dir);
    dirp->dir = NULL;

    return Qnil;
}
dir.each { |filename| block } → dir
dir.each → an_enumerator

Calls the block once for each entry in this directory, passing the filename of each entry as a parameter to the block.

If no block is given, an enumerator is returned instead.

d = Dir.new("testdir")
d.each  {|x| puts "Got #{x}" }

produces:

Got .
Got ..
Got config.h
Got main.rb
static VALUE
dir_each(VALUE dir)
{
    struct dir_data *dirp;
    struct dirent *dp;
    IF_HAVE_HFS(int hfs_p);

    RETURN_ENUMERATOR(dir, 0, 0);
    GetDIR(dir, dirp);
    rewinddir(dirp->dir);
    IF_HAVE_HFS(hfs_p = is_hfs(dirp->dir));
    while ((dp = READDIR(dirp->dir, dirp->enc)) != NULL) {
        const char *name = dp->d_name;
        size_t namlen = NAMLEN(dp);
        VALUE path;
#if HAVE_HFS
        if (hfs_p && has_nonascii(name, namlen) &&
            !NIL_P(path = rb_str_normalize_ospath(name, namlen))) {
            path = rb_external_str_with_enc(path, dirp->enc);
        }
        else
#endif
        path = rb_external_str_new_with_enc(name, namlen, dirp->enc);
        rb_yield(path);
        if (dirp->dir == NULL) dir_closed();
    }
    return dir;
}
dir.inspect → string

Return a string describing this Dir object.

static VALUE
dir_inspect(VALUE dir)
{
    struct dir_data *dirp;

    TypedData_Get_Struct(dir, struct dir_data, &dir_data_type, dirp);
    if (!NIL_P(dirp->path)) {
        VALUE str = rb_str_new_cstr("#<");
        rb_str_append(str, rb_class_name(CLASS_OF(dir)));
        rb_str_cat2(str, ":");
        rb_str_append(str, dirp->path);
        rb_str_cat2(str, ">");
        return str;
    }
    return rb_funcall(dir, rb_intern("to_s"), 0, 0);
}
dir.path → string or nil

Returns the path parameter passed to dir's constructor.

d = Dir.new("..")
d.path   #=> ".."
static VALUE
dir_path(VALUE dir)
{
    struct dir_data *dirp;

    TypedData_Get_Struct(dir, struct dir_data, &dir_data_type, dirp);
    if (NIL_P(dirp->path)) return Qnil;
    return rb_str_dup(dirp->path);
}
dir.pos → integer

Returns the current position in dir. See also Dir#seek.

d = Dir.new("testdir")
d.tell   #=> 0
d.read   #=> "."
d.tell   #=> 12
static VALUE
dir_tell(VALUE dir)
{
    struct dir_data *dirp;
    long pos;

    GetDIR(dir, dirp);
    pos = telldir(dirp->dir);
    return rb_int2inum(pos);
}
dir.pos = integer → integer

Synonym for Dir#seek, but returns the position parameter.

d = Dir.new("testdir")   #=> #<Dir:0x401b3c40>
d.read                   #=> "."
i = d.pos                #=> 12
d.read                   #=> ".."
d.pos = i                #=> 12
d.read                   #=> ".."
static VALUE
dir_set_pos(VALUE dir, VALUE pos)
{
    dir_seek(dir, pos);
    return pos;
}
dir.read → string or nil

Reads the next entry from dir and returns it as a string. Returns nil at the end of the stream.

d = Dir.new("testdir")
d.read   #=> "."
d.read   #=> ".."
d.read   #=> "config.h"
static VALUE
dir_read(VALUE dir)
{
    struct dir_data *dirp;
    struct dirent *dp;

    GetDIR(dir, dirp);
    errno = 0;
    if ((dp = READDIR(dirp->dir, dirp->enc)) != NULL) {
        return rb_external_str_new_with_enc(dp->d_name, NAMLEN(dp), dirp->enc);
    }
    else {
        if (errno != 0) rb_sys_fail(0);
        return Qnil;           /* end of stream */
    }
}
dir.rewind → dir

Repositions dir to the first entry.

d = Dir.new("testdir")
d.read     #=> "."
d.rewind   #=> #<Dir:0x401b3fb0>
d.read     #=> "."
static VALUE
dir_rewind(VALUE dir)
{
    struct dir_data *dirp;

    GetDIR(dir, dirp);
    rewinddir(dirp->dir);
    return dir;
}
dir.seek( integer ) → dir

Seeks to a particular location in dir. integer must be a value returned by Dir#tell.

d = Dir.new("testdir")   #=> #<Dir:0x401b3c40>
d.read                   #=> "."
i = d.tell               #=> 12
d.read                   #=> ".."
d.seek(i)                #=> #<Dir:0x401b3c40>
d.read                   #=> ".."
static VALUE
dir_seek(VALUE dir, VALUE pos)
{
    struct dir_data *dirp;
    long p = NUM2LONG(pos);

    GetDIR(dir, dirp);
    seekdir(dirp->dir, p);
    return dir;
}
dir.tell → integer

Returns the current position in dir. See also Dir#seek.

d = Dir.new("testdir")
d.tell   #=> 0
d.read   #=> "."
d.tell   #=> 12
static VALUE
dir_tell(VALUE dir)
{
    struct dir_data *dirp;
    long pos;

    GetDIR(dir, dirp);
    pos = telldir(dirp->dir);
    return rb_int2inum(pos);
}
dir.to_path → string or nil

Returns the path parameter passed to dir's constructor.

d = Dir.new("..")
d.path   #=> ".."
static VALUE
dir_path(VALUE dir)
{
    struct dir_data *dirp;

    TypedData_Get_Struct(dir, struct dir_data, &dir_data_type, dirp);
    if (NIL_P(dirp->path)) return Qnil;
    return rb_str_dup(dirp->path);
}