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OTHER SYSTEM FUNCTIONS
27.4
~-
Diskette File Functions
27. 4. 1 Oi
rec tortj searc h -
.
DIRSM
The .DIRSM function performs directory searches based on
va~ious
criteria.
This function can
be
used
ror
finding,
creating,
or deleting directory entries on an
MDOS
diskette.
ENTRY PARAMETERS:
B
contains
a
function code that speciFies
the action to be performed by .DIRSM.
x
=
Tn
e add res s
0
f
the
DFT.
A 11
c a
11
s to
.DIRSM
require that LUN contains the
logical unit number
to
be
accessed
(ASCII number
0-3,
$30-$33),
that SBS
contains the starting
address
oT
a
128
(decimal) byte sector buffer,
and
that
SBE
contains the ending
address
of
the sector buffer.
If
the sector
buffer
is
larger
than
a
single
sec tor ,on
1 y the
r
irs t
1 28
b
Y
t
e
s
UJ
ill
be used.
The
following Function codes
ror
the
B
register are defined:
B
=
1
indicates
to
search. ror
and
B
=
B
=
retrieve
the
next,
non-deleted
d i rec tory
entry.
The
DFT must have
DEN
=
0
ror the
initia.l
call.
The
D~N
must
then
remain unchanged for
subsequent calls since it is used
to
determine
where
to resume the search.
The contents
or
the
sector
bu~fer
must
also
remain
unchanged between
successive calls
for
this
function
code.
2
indicates
to
search
ror
and
retrieve a
directory
entry
with
a
speci-Fic
rile
name and su-Frix.
The
DFT entries
NAM
and SUF are
used
to
speciry the rile name.
4
indicates
to
create a new unique
di1"ectory entry OT a given
name
and
suffix.
Initial
diskette
space
allocation
is
performed
ir
the
directory
entry is cre,ated.
The OFT
entries
NAM
and
SUF
are
used
to
sp
ec i f-y
the
directory
entry·
to be
created.
A
search of
the
directory
is performed
ror
this entry to ensure
that it does not already
ex
i
st.
Tne
OFT
entries FDF and 51Z must also be
Page
----
.
\
I
--'"
_ /
27-14
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