|
class Dir
|
|
Parent:
|
Object
|
|
Version:
|
1.6
|
|
Index:
[ ]
chdir
chroot
delete
entries
foreach
getwd
glob
mkdir
new
open
pwd
rmdir
unlink
close
each
read
rewind
seek
tell
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, page
301.
The directory used in these examples contains the two regular files
(
config.h and
main.rb), the parent directory (
..), and
the directory itself (
.).
|
mixins
|
| Enumerable:
|
collect, detect, each_with_index, entries, find, find_all, grep,
include?, map, max, member?, min, reject, select, sort, to_a |
|
class methods
|
|
[ ]
|
Dir[ aString ]
-> anArray
|
|
Returns anArray of filenames found by
expanding the pattern given in aString.
Note that this pattern is not a regexp (it's closer to a shell glob)
and may contain the following metacharacters:
 |
**
|
Matches subdirectories recursively |
*
|
Matches zero or more characters |
?
|
Matches any single character |
[ charSet ]
|
Matches any character from the given
set of characters. A range of characters is written as
charFrom
-
charTo. The set may be negated
with an initial uparrow (^). |
{ opt, opt, ... }
|
Matches any one of the
optional strings |
|
Dir["config.?"]
|
» |
["config.h"]
|
Dir["*.[a-z][a-z]"]
|
» |
["main.rb"]
|
Dir["*.[^r]*"]
|
» |
["config.h"]
|
Dir["*.{rb,h}"]
|
» |
["main.rb", "config.h"]
|
Dir["*"]
|
» |
["config.h", "main.rb"]
|
|
|
chdir
|
Dir.chdir( [ aString
] )
-> 0
|
|
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.
Raises a SystemCallError (probably Errno::ENOENT)
if the target directory does not exist.
Dir.chdir("/var/spool/mail")
|
» |
0
|
Dir.pwd
|
» |
"/var/spool/mail"
|
|
|
chroot
|
Dir.chroot( aString )
-> 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.
Dir.chdir("/production/secure/root")
|
|
Dir.chroot("/production/secure/root")
|
»0
|
Dir.pwd
|
»"/"
|
|
|
delete
|
Dir.delete( aString )
-> 0
|
|
Deletes the named directory. Raises a subclass of
SystemCallError if the directory isn't empty.
|
|
entries
|
Dir.entries( aString )
-> anArray
|
|
Returns an array containing all of the filenames in the given
directory. Will raise a SystemCallError if the named directory
doesn't exist.
Dir.entries("testdir")
|
» |
[".", "..", "config.h", "main.rb"]
|
|
|
foreach
|
Dir.foreach( aString )
{| filename | block }
-> nil
|
|
Calls the block once for each entry in the named directory,
passing the filename of each entry as a parameter to the block.
Dir.foreach("testdir") {|x| puts("Got " + x) }
|
produces:
Got .
Got ..
Got config.h
Got main.rb
|
|
|
getwd
|
Dir.getwd
-> aString
|
|
Returns the path to the current working directory of this
process as a string.
Dir.chdir("/tmp")
|
» |
0
|
Dir.getwd
|
» |
"/tmp"
|
|
|
glob
|
Dir.glob( aString )
-> anArray
|
|
Synonym for
Dir.[]
.
|
|
mkdir
|
Dir.mkdir( aString [, anInteger
] )
-> 0
|
|
Makes a new directory named by aString, 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 on page 301.
|
|
new
|
Dir.new( aString ) -> aDir
|
|
Returns a new directory object for the named directory.
|
|
open
|
Dir.open( aString ) -> aDir
Dir.open( aString ) {| aDir | block }
-> nil
|
|
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 nil.
|
|
pwd
|
Dir.pwd -> aString
|
|
Synonym for
Dir.getwd
.
|
|
rmdir
|
Dir.rmdir( aString )
-> true
|
|
Synonym for
Dir.delete
.
|
|
unlink
|
Dir.unlink( aString )
-> true
|
|
Synonym for
Dir.delete
.
|
|
instance methods
|
|
close
|
dir.close
-> nil
|
|
Closes the directory stream.
Any further attempts to access dir will raise an
IOError.
d = Dir.new("testdir")
|
d.close
|
» |
nil
|
|
|
each
|
dir.each {| | block }
-> dir
|
|
Calls the block once for each entry in this directory,
passing the filename of each entry as a parameter to the block.
d = Dir.new("testdir")
d.each {|x| puts ("Got " + x) }
|
produces:
Got .
Got ..
Got config.h
Got main.rb
|
|
|
read
|
dir.read
-> aString 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"
|
|
|
rewind
|
dir.rewind
-> dir
|
|
Repositions dir to the first entry.
d = Dir.new("testdir")
|
d.read
|
» |
"."
|
d.rewind
|
» |
#<Dir:0x401b5cac>
|
d.read
|
» |
"."
|
|
|
seek
|
dir.seek( anInteger )
-> dir
|
|
Seeks to a particular location in dir.
anInteger must be a value returned by
Dir#tell
.
d = Dir.new("testdir")
|
d.read
|
» |
"."
|
i = d.tell
|
d.read
|
» |
".."
|
d.seek(i)
|
» |
#<Dir:0x401b5cac>
|
d.read
|
» |
".."
|
|
|
tell
|
dir.tell
-> anInteger
|
|
Returns the current position in dir. See also
Dir#seek
.
d = Dir.new("testdir")
|
d.tell
|
» |
0
|
d.read
|
» |
"."
|
d.tell
|
» |
12
|
|
Extracted from the book "Programming Ruby -
The Pragmatic Programmer's Guide"
Copyright
©
2001 by Addison Wesley Longman, Inc. This material may
be distributed only subject to the terms and conditions set forth in
the Open Publication License, v1.0 or later (the latest version is
presently available at
http://www.opencontent.org/openpub/)).
Distribution of substantively modified versions of this document is
prohibited without the explicit permission of the copyright holder.
Distribution of the work or derivative of the work in any standard
(paper) book form is prohibited unless prior permission is obtained
from the copyright holder.