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ATTRIB
CHAPTER 6
COMMANDS
AND STATEMENTS
The A TTRIB command changes certain specified attributes
of
BASIC-80 disk files.
You can protect any file from writing or deleting or renaming by enabling the 'write
protect' attribute, and you can later disable this attribute to alter or delete the
specified file. The formats for these two operations are given below.
You can also enable
or
disable other file attributes with the A TTRIB command.
Refer to the
ISIS-II
User's Guide, File Control Commands, for information on
using ATTRIB with system, format, and invisible attributes.
To protect a file from writing, deletion, and renaming:
ATTRIB ":Fdrive number:filename",
"W1"
To write to, delete,
or
rename a previously protected file:
ATTRIB
":Fdrive
number:filename", "WO"
AUTO
The AUTO command automatically generates a line number
at
the beginning of
each line when you are entering a program. The first operand specifies the number
of
the first line entered after the AUTO command; the second, which
is
optional,
specifies the increment. Both operands default to
10.
AUTO [first line
J[,
increment]
To number lines starting with
10
in increments
of
10:
AUTO
To number lines with an increment
of
50
starting with line 300:
AUTO 300,50
If
AUTO generates a line number that already exists in the program, the generated
number
is
followed by
an
asterisk. To erase the existing line, enter CR; to leave that
line in the program, enter Control-C to stop the
AUTO process.
CLEAR
The CLEAR command sets all variables, arrays, and function definitions to zero,
and closes files.
If
variables are referenced after a CLEAR, numeric variables
will
be
zero and string variables will be null. The first expression
is
specified as
an
argu-
ment, and the value
of
this expression becomes the string space,
in
bytes.
CLEAR [expression[,address]]
6-1