COMPUTING FOR THE BEWILDERED
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File Management
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As a companion to the presentation of file management in Moira
Stephen's book, I'd like to spend some time going through the origins
of the filing system usually used with the Windows operating system,
which is based on the earlier DOS OS.

The following has been adapted from an older booklet of mine written
for classes taking a formal exam in file management; much of it is
still relevant.

Before I reproduce it, just a confirmation.  Folders and Directories
are exactly the same thing.  Folders is the newer name, directories the
older.


FILES

Work is stored on disk in FILES. Each file will have a filename and
(usually) an extension. The filename can be up to 8 characters and the
filename up to three. The name and extension are separated by a full
stop. Windows 95 and later allow longer filenames.

Examples of filenames are:

CONFIG.SYS
COMMAND.COM
CHESS.EXE
MYWORK.TXT
READ.ME



Certain extensions are reserved to mean certain things:

SYS - a SYStem file or device driver
COM - a COMmandable file
EXE - an EXEcutable file
BAT - a BATch file.




SYS files are normally only accessed on system start-up or "boot"

COM EXE and BAT files are the files which can be run from the "run"
command or a  command line. For the average user, there is no
difference between COM and EXE programs. However, BAT files are text
files of lists of instructions that are well within the capabilities of
average users to create. BAT files were poorly catered for under
Windows 95 and Windows 98.  However, the most recent versions of
Windows has reintroduced the concept, as a script file.
Other extensions are conventionally used for specific purposes although
not demanded by Windows. Some of the more common are:




DOC - a document file created by a word processing package
TXT - an ASCII text file
INI - a program initiation file.



DRIVES
The different drives on your computer are labelled by letters of the
alphabet followed by a colon, viz.:

A: B: etc.

All PCs have an A: This is the floppy drive from which the computer can
be booted. A system disk in A: can always be used to boot from even if
there is a bootable hard disk.

A second floppy if fitted will be B:. If there is no second floppy, the
first can also be accessed as B:.

Windows has the ability to divide hard disks into partitions, each with
its own drive letter. You may therefore have one hard disk which is
divided into two or more drives (these are called logical drives), or
you can have two or more hard disks, any of which may contain logical
drives.

Whatever the arrangement, the first partition on the first hard disk is
C:, and is normally bootable, so the computer will boot without the
need to insert a system disk. Large systems have many drives; the
author's system currently goes to J:.



Other devices, notably CD-ROM drives, also have a drive letter. These
letters are allocated on boot after all the hard disk partitions have
been accounted for. For most purposes, CD-ROMs can be regarded as very
large read-only floppy disks!



In order to make organising disks more easy, drives can be divided into
subdirectories. Hard disks are always so divided, floppy disks less
often.

The root, or main directory, (sometimes called top level directory) is
the one that always exists, and from which other directories, often
called subdirectories, branch.

The rules for directory names are exactly the same as those for files,
although extensions are not normally used.

The layout of directories and files on a disk is called a TREE. Here is
a simple example:

C:
|-COMMAND.COM 		File in root directory
|-AUTOEXEC.BAT "
|-CONFIG.SYS "
|-DOS 			Directory
| |-CHKDSK.EXE 		File in DOS subdirectory
| |-KEYB.COM "
| |-etc. etc.
|-WORKS 		Directory
| |-WORKS.EXE		File in WORKS subdirectory
| |-WORDS		Subdirectory of WORKS
| | |-LETTER1.DOC 	File in WORKS\WORDS subdirectory
| | |-LETTER2.DOC 		"
| |-SPREAD 		Subdirectory of WORKS
| | |-SHEET1.WS		File in WORKS\SPREAD subdirectory
| | |-SHEET2.WS "

Note the use of the \ (backslash) above. To give the full location
(PATH) of a file, we use the form:

C:\WORKS\SPREAD\SHEET2.WS

This means "the file SHEET2.WS, found in the SPREAD subdirectory of the
WORKS subdirectory on C:"

When housekeeping in DOS or Windows, it is not always necessary to
quote the full path, but it is NEVER, EVER WRONG to do so, and may
prevent errors.

Although most file management operations are nowadays performed from
the Windows desktop, command line operation is not only still a part of
your tools, but has been brought back to prominence in Windows XP with
the command interpreter CMD.EXE.  It is not necessary to learn the
command line in order to keep your disks in order, but it is often very
much quicker.