IBM Professional Series User Manual page 94

manipulation commands. Be sure that you understand the
system action and purpose for filemode before you specify a
mode other than AI.
Filetype specifies the type of data contained in the file.
VM/PC recognizes some specific file types that give the file
contents special meaning. Files containing programs have a
file type that identifies the source language interpreter or
compiler. For example, EXEC/EXEC2, FORTRAN,
COBOL, and ASSEMBLER language programs are stored in
files with EXEC, FORT, COBOL, and ASSEMBLE
filetypes respectively.
You can specify any filetype that you choose for files
containing data. There are, however, certain programs that
require their input data to be stored in files with a specific
filetype. SCRIPT is an example of such a program -- it
requires data to be in a file with a filetype of SCRIPT.
Finally, the filename is the least restrictive of the three
elements. A filename may be up to eight numbers and
letters, in any combination that you choose. You will find
that filenames that help identify the file contents are the
most useful. When used in combination with the 8-character
filetype, the fn
ft
can readily identify a specific file or group
of files according to content.
In the examples that follow, files containing similar types of
data have the same filetype. For example, you can name
files containing monthly reports JAN84 REPORT, FEB84
REPORT, MAR84 REPORT, etc. You can choose a
filetype of CALENDAR for files containing daily calendar
information. 112383 CALENDAR, for example, might
contain daily calendar information for November 23, 1983.
MEMO TOJOE would be a good name for a file containing
a message for Joe until you find it necessary to distinguish
one message to Joe from another. You will discover more
uses for grouping filetypes later, when you read about other
file manipulation commands.
When you type commands, be sure to type them as they are
shown in this book, including spaces if there are any.
If
a
Chapter 5. Using VM/PC Commands to Do Work 5-3