Java IO.pdf - Nguyen Dang Binh

Java I/O
Windows NT supports multiple kinds of filesystems, including FAT (the basic DOScompatible
filesystem) and NTFS (NT File System). NT 3.5.1 and earlier (but not NT 4.0 and
later) support OS/2's HPFS. Each of these filesystems supports a slightly different set of
attributes. They all support a superset of the basic DOS/Windows file attributes, including
creation time, modification time, access time, allocation size, file size, and whether the file is
read-only, system, hidden, archive, or control.
On Unix, file attributes may be viewed by using the -l switch to the ls command:
% ls -l
total 3408
-r--r--r-- 1 root other 89795 Aug 30 14:41 CHANGES
-r--r--r-- 1 root other 896 Aug 30 14:41 COPYRIGHT
-r--r--r-- 1 root other 5994 Aug 30 14:41 LICENSE
-r--r--r-- 1 root other 34689 Aug 30 14:41 README
drwxr-xr-x 3 root other 512 Oct 17 10:31 bin
drwxr-xr-x 24 root other 512 Oct 16 21:07 demo
drwxr-xr-x 4 root other 1024 Oct 17 10:31 include
-r--r--r-- 1 root other 2497 Aug 30 14:41 index.html
drwxr-xr-x 4 root other 1024 Oct 17 10:32 lib
-rw-r--r-- 1 root other 1593763 Aug 30 14:40 src.zip
The first column is a series of character flags indicating, respectively, the type of the file; the
owner's read, write, and execute permissions; the group's read, write and execute permissions;
and the world's read, write, and execute permissions. The number following that is the
number of links to this file. The next word, root in all these cases, is the username of the
owner of the file. The second word, other in this example, is the group associated with the
file. The following number is the size of the file in bytes. This is followed by the last
modification date of the file. The last column contains the name of the file itself.
The attributes of a Windows file may be viewed from a DOS window with the DIR command:
C:> DIR/X
Volume in drive C has no label.
Volume Serial Number is 9460-4CAA
Directory of C:\
12/31/96 04:03p 0 AUTOEXEC.BAT
12/31/96 04:03p 0 CONFIG.SYS
12/31/96 04:48p MSOffice
11/12/97 11:28a 45,088,768 pagefile.sys
11/05/97 08:13p Pro18
12/31/96 03:54p PROGRA~1 Program Files
12/31/96 04:03p TEMP
11/12/97 11:29a WINNT
8 File(s) 45,088,768 bytes
640,570,880 bytes free
This shows the file's name, optionally its short name, the size of the file in bytes (if it's not a
directory), and the date and time when the file was created. With the /T:A or /T:W flags, you
would see the time the file was last accessed or written (modified), respectively. DOS won't
show you the archive, hidden, system, or read-only flags directly, but by using the /A:A,
/A:H, /A:S, or /A:R flags, you can list only those files that have the specified attributes. By
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