|A filename is divided into two parts - the name and the extension.
On some systems, filenames must comply with what is known as the
8.3 naming convention - all this means is that there can
be no more than eight letters in the filename, followed by a dot,
and then three letters after the dot. Most computers now will
deal with longer filenames, so the days when files had to be given
names like jslet3sl.doc or names truncated as in tchaikov.doc
are thankfully over.
However there are still occasions when 8.3 filenames are used.
Particularly if you are transferring information from one computer
to another (and you don't know what system is being used) or one
medium to another (i.e. hard disc to CD-ROM), it is a good idea
to minimize risk by putting information which differentiates one
file from another in the first eight letters, just in case.
For example, let's say you had three files about Swan Lake on
your computer -
Swan Lake history.doc
Swan Lake background.doc
Swan Lake music.doc
This is all fine on your computer. You save your work to
floppy disc, and then take it to a friends house, who has an older
computer which cannot deal with filenames not in 8.3 format.
This is what you'll see -
Better then, either to create a folder called swanlake (which
is thankfully only eight letters long) and then create files within
that folder called history.doc, bkground.doc, music.doc like so:
or use an prefix like SL for things to do with Swan Lake,
so you get SLhistory, SLbackground.doc, SLmusic.doc. Like
this, you can still have a file with characters (if you must)
but the most relevant detail will be within the first eight characters.
Reserved characters are characters which cannot be used in a filename,
because they have been "reserved" by the system to denote other
things. These characters are:
The chevron <
The asterisk *
The question mark ?
The forward slash /
The backslash \
Quotation marks "
Pipe symbol |
It is easy to see why the backslash (\) is a reserved character
- it denotes, as we have seen, a directory or folder. Thus,
a file cannot be called exercises\enchainements.doc because
the slash would indicate that there was a folder called "exercises"
and in that folder there is a document called "enchainements.doc".
Case Sensitivity and Spaces
Many systems allow uppercase letters in filenames, and spaces,
and 255 characters in a filename. Wonderful news - but again,
prepare for the worst. Case-sensitivity means that
your computer will differentiate between Letter.doc and letter.doc
- in other words, it is sensitive to the fact that one L is upper
case, and the other l is lower case.
Calling one file Letter.doc and another letter.doc
is not a good idea - will you remember which one contains
what? Furthermore, just because your computer knows
the difference, does not guarantee that someone else's will.
Likewise, not all systems like spaces in filenames, so you might
like to adopt a policy for filenaming which will not crumble under
pressure - particularly if you are publishing files on the internet,
or sending files for publication. A fairly catch-all, failsafe
policy is no spaces, all lower case, i.e.
John Smith letter 1998.doc
The three letters after the dot are known as the file extension,
and tell you (and the computer) what sort of file it is.
You are probably familiar with the .doc extension, used for Word
documents. Knowing what file extensions are is essential to your
sanity, and your computer's.
Here are a very few file extensions - . If you have
found a file with an extension you don't recognise, and want to
know what it is, one way to find out (without buying a dictionary
of file extensions, or searching on your computer's help menus)
is to search on Kresch.com's
file extension database on the web. Karl Resch also has a
of 1000 file extensions for that rainy November evening.
||A document (file) created in Microsoft word
||A text only file - i.e. without any formatting such as indented
paragraphs, heading hierarchies etc
||Word backup file - a file that holds the last saved version
of what you did, so that you can revert to it if you want
||A "JPEG" (pronounced jay-peg) compressed image file, used
widely on the internet since the compression results in a
smaller file size
||A GIF file - another compressed file
||Windows bitmap - an uncompressed file. "Wallpaper"
pictures on your desktop are usually in this format
||Real Audio Media file -
||a compressed audio file
||A MIDI (musical instrument digital interface) file - technically
not a sound file, since it does not "contain" sound, but instructions
to musical instruments (such as a keyboard or the internal
synthesizer in a computer) which will intern cause music to
||An uncompressed sound file
|PROGRAM AND SYSTEM FILES
||Short for "executable file", program (application) files
end in ".exe" (often known as "eksee files").
||Dynamic library link - a system file
||Initialization file - contains information about how a program
is set up - preferences and options, for example.
|.zip, .z, .tar, .lzw
||A compressed file
||An icon file
||(portable document format) A file that can be read by Acrobat
||(Hypertext Markup Language) A document formatted with special
codes that can be read and interpreted by web browsers