Texas Instruments TI-89 - Cmd_Lock

1134
Appendix A: System Routines — Variables
TI
-
89 / TI
-
92 Plus Developer Guide
Not for Distribution
Beta Version January 26, 2001
cmd_lock
Declaration:
void
cmd_lock
(EStackIndex
sym
)
Category(ies):
Variables
Description:
Lock one or more variables. This is the TI
-
BASIC command Lock.
Inputs:
sym
— EStackIndex of variable name(s) to lock (terminated by an
END_TAG).
Outputs:
May throw these errors:
ER_VAR_IN_USE — Variable is in-use.
ER_UNDEFINED_VAR — Variable not found.
ER_RESERVED — Reserved or system names cannot be locked
or unlocked.
Assumptions:
None
Side Effects:
None
Availability:
On AMS 1.05 and higher.
TI
-
89 / TI
-
92 Plus
Differences:
None
See Also: TokenizeSymName, cmd_unlock
Example:
This example locks or unlocks the variable name in
varName.
void LockOp( BYTE *varName, BOOL LockIt ) {
EStackIndex volatile oldTop = top_estack; /* save top of ESTACK */
TRY
push_quantum (END_TAG); /* mark end of parameter list */
if (TokenizeSymName( varName, 0 ) == NULL) /* push tokenized name on ESTACK */
ER_THROW( INVALID_PATHNAME_ERROR );
LockIt ? cmd_lock(top_estack) : cmd_unlock(top_estack);
top_estack = oldTop; /* restore top of ESTACK */
ONERR
top_estack = oldTop; /* restore top of ESTACK */
PASS; /* pass error on up to caller */
ENDTRY
}