HP 3000 Manuals HP 3000 Manuals
The Location of Files
The account structure of the computer is analogous to a room full of
filing cabinets--a place, or places, for the orderly storage of
information in files (Figure 2-1 ).
This picture is not literally accurate. From a technical point of view,
it is a little misleading to think of computer files as being in places
such as the drawer of a filing cabinet. But that description helps to
explain the organization of the account structure. If the image of a
cabinet full of drawers and files is useful to you, then keep it in mind.
If you are looking for a file called MYREPORT and you know that it is in
the filing cabinet called ANYACCT, in the filing drawer called MYGROUP,
you would log on in this way:
HELLO JOHN.ANYACCT,MYGROUPReturn
________________________________________________________________________
|Notice that although you are looking for a particular file, it is not |
|necessary--it is not even possible--to name the file when you |
|log on. You need to name the filing cabinet (account) and the |
|drawer (group) and the key (user name) attached to the filing |
|cabinet. |
________________________________________________________________________
If you had logged on to a group called YRENDSUM in the ANYACCT account
and you wanted to see the contents of the file TAXRPT in the MYGROUP
group, you would do this:
PRINT TAXRTP.MYGROUP.ANYACCT
________________________________________________________________________
|Access to a file is governed by the security provisions in effect on |
|your computer. While you may be able to find a file, you might--or |
|might not--be able to see its contents, copy it, use it, or change |
|it. |
________________________________________________________________________
File names and logons
Have you noticed something a little odd?
The fully qualified name of the file called MYREPORT is this:
MYREPORT.MYGROUP.ANYACCT
file name.group name.account name
Nevertheless, in order to log on to the group in which this file is
found, you would enter this:
HELLO JOHN.ANYACCT,MYGROUPReturn
HELLO user name.account name,group name
The user name and the account name are the two most critical elements of
the logon. The group, which is only part of an account, is added to the
logon almost as a qualifier.
Types of files
Files may be written in ASCII form. Typically, these are text files of
the sort that you might create while writing a letter or a report. If
you use the PRINT command to examine them, they appear on your screen as
you recorded them, in recognizable letters, numbers, and symbols.
Still other files are written in binary form, the language that computers
truly understand. Programs are usually recorded in binary form, and so
are illustration files that are called graphics. Binary is the recording
form for most databases, too.
Execution or information
A last distinction among files is between executable files (programs) and
data files (all others).
Executable files provide instruction for the computer to do something.
Executable files are usually in binary form, although some, such as
command files and job files are written in ASCII.
Data files hold information. Data files may be in ASCII or in binary
form.
Mnemonics
The possible variations in file structure, type, and purpose are
numerous. At the time it is recorded, each file is assigned a number or
a mnemonic code. A mnemonic is a clue, usually a name or some
descriptive word, designed to help you remember something. These serve
to identify how the file was created and for what purpose. The code
number for the EDIT/3000 program is 1029. Its mnemonic code is PROG,
because it is a program.