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GENERAL SYSTEM OPERATION
2.7 -- Diskette File Concepts
directory entries with the
~ile
name "FILE
su~fix
on the default drive.
Similarly,
II
but Ulith
an"
PROG*.SA
is
a
file
name
specification
that
includ~s
all directory
entries with "PROG
u
as the first
four
characters
of
their
file
names, regardless of Ulhat the remaining characters arel
and with suffix "SAil on
the
default
drive.
The
asterisk
cannot
have
characters
following
it.
Thus; the following
file name specifications are invalid:
*PROQ. SA
PROGRAM.*B
Not all
commands
allow
file
contain
the
family
indicator.
descriptions
should
be
consulted
indicators are acceptable.
2.7.1.2 Device specifications
name
speciFications
to
The
individual
command
to
see
where
family
Some
commands
allow
the
operator
to
enter a device
specification in the command line
instead
of
a
File
name
specification.
Device
specifications consist of two parts:
a "device. name
II
and
an
optional
"logical
unit
number".
Device
names
are two characters long,
both of which must be
alphabetic.
A pound sign
(#)
is used as a leading
character
to
indicate
that the subsequent two-character sequence is a
device name.
For example,
#LP
#CN
are valid device names used ror
the
line
~~int~r
and
the
console, respectively.
A device specirication may be entered
with a logical unit number.
Logical unit numbers must
rollo~
the device name and must be separated -rl'om it by a colon (: >.
The individual command descriptions should
be
consulted
to
see where device specirications are allowed.
2.7.2 File creation
MDOS riles are
nev~r
explicitly created by the operator.
All commands that write to
output
riles
~ill
create
them
automatically
ir
they
do not exist.
Files will be created
according to the rile name specification given on the command
line.
That is,. if explicit suffixes and logical unit numb.ers
are specified, the rile will
be
created
on
the
indicated
drive.
Otherwise, the appropriate default values supplied
by
~ne
command will be used to
c~eate
the rile.
Existing
riles
are unaffected
by
the creation of a new file.
Page
02-14
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