A useful alternate form
of
the command
is:
VERIFY"*"
,device #
It verifies the last files used without having
to
type its name or drive number. However, it
won't work properly after SAVE-WITH-REPLACE, because the last file used was the
one deleted, and the drive will try
to
compare the deleted
file
to
the program in memory.
No harm will result, but "VERIFY ERROR" will always be announced. To use VERIFY
after @SAVE, include at least part
of
the
file
name that
is
to be verified in the pattern.
One other note about
VERIFY-when
you VERIFY a relocated BASIC file,
an
error
will nearly always be announced, due
to
changes in the link pointers
of
BASIC programs
made during relocation.
It
is best
to
VERIFY files saved from the same type
of
machine,
and identical memory size. For example, a BASIC program saved from a Plus/4 can't be
verified easily with a C64, even when the program would work
fine
on both machines.
This shouldn't matter,
as
the only time you'll be verifying files on machines other than the
one which wrote them
is
when you are comparing two disk files to see if they are the
same. This is done by loading one and verifying against the other, and can only be done
on the same machine and memory size
as
the one on which the files were first created.
SCRATCH
The SCRATCH command allows you
to
erase unwanted files and free the space they
occupied for use
by
other files. It can be used
to
erase either a single
file
or several files at
once via pattern-matching.
FORMAT
FOR
THE
SCRATCH
COMMAND:
PRINT#15, "SCRATCH(I):pattern"
or abbreviate it
as:
PRINT # 15, "S(I):pattern"
"pattern"
can be any
file
name or combination
of
characters and wild-card characters.
As
usual, it
is
assumed the command channel has already been opened
as
file
15.
Although
not absolutely necessary, it
is
best
to
include the drive number
in
SCRATCH commands.
If
you check the error channel after a SCRATCH command, the value for ET (error
track) will tell you how many files were scratched. For example, if your diskette contains
program files named
"TEST,"
"TRAIN,"
"TRUCK,"
and
"TAIL,"
you may
SCRATCH all four, along with any other files beginning with the letter' 'T," by using the
command:
PRINT#15, 'SO:T*'
Then, to prove they are gone, you can type:
GOSUB 59990
18
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