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OTHER
SYSTEM
FUNCTIONS
27.4 -- Diskette File Functions
error, a special message will be displayed.
the -format:
**
INVALID MESSAGE \3 AT \8
This message has
The
"\3"
parameter
will
have been replaced
with
the index
number of the error message
that
the
.MDERR
function
was
tr~ing
to
display.
This
mayor may not be a valid index
number, depending on whether or not the
MDOS
error
message
file
could
be
~roperly
accessed.
The
"\8"
parameter will
have been replaced with the address of the call to the .MDERR
system
function.
In
the
event
that
this
message
is
displayed,
the Error Type portion of the system error
status
word
will
contain the value
SFF
(the Error Status Flag will
also be set to one).
27. 5 Other Functions
The remaining system functions are so diverse that
they
fail
to
fall
into
one
of the previous categories.
These
functions are used
by
the MDOS commands and are available for
user
programs
in
o~der
to
extract. file
name
or device
specifications from the MDOS command line,
allocate
program
memory
in
the remaining block of contiguous memorYI set the
sqstem error status word when non-standard
~rror
messages are
displayed
so
that
CHAIN
processing will work properly, and to
return control to the
MOOS
command interpreter.
27.5.1 Process
~ile
name --
.PFNAM
The .PFNAM function scans a speciried input bUTTer ror a
file
name
or
device
specification.
The
information
is
returned in a format which is called the standard
MDOS
Tile
name
format.
This
format
fits
into
the other parameter
tables required
by
the
device
independent
I/O
functions
(IOCB)
and
the
diskette
rile functions
(DFT).
The.
PFNAM
function will also recognize familq indicators in either
the
file name or the suffix.
Due to the nature of the free format of the
MDOS
command
line, any character that will not be confused with
a
device
name
indicator,
a
family
indicator, a suffix delimiter, a
logical unit delimiter, an option field delimiter, or an
end
of
line
delimiter
will be used to terminate the scan for a
valid file name or device specification.
The scan will never continue beyond an option
delimiter
( i )
or an end of line delimiter (carriage return), regardless
of the number of times
.PFNAM
is called with the scan pointer
pointing to such a character.
ENTRY PARAMETERS;
x
=
The
address
of
a file name packet.
Page
27-35
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