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 (Title not available).
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
|
 |
| |
|
 | TIP: 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
|
|
| |
|
| TIP: 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.
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.
Still other types of files are called byte stream files. These files are simply a sequence (stream) of bytes. The term byte stream file is frequently used when talking about files with the byte stream record type, even though they are not a new file type. Byte stream files do not have any record structure associated with them and have a record size of 1 byte. Also, they allow reading and writing of data in arbitrary chunks.
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.
