Cmd_Lock - Texas Instruments TI-89 Developer's Manual

1134

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
Outputs: May throw these errors:
ER_VAR_IN_USE
ER_UNDEFINED_VAR — Variable not found.
ER_RESERVED
Assumptions: None
Side Effects: None
Availability: On AMS 1.05 and higher.
TI-89 / TI-92 Plus
Differences: None
See Also: TokenizeSymName, cmd_unlock
This example locks or unlocks the variable name in varName.
Example:
void LockOp( BYTE *varName, BOOL LockIt ) {
EStackIndex volatile oldTop = top_estack; /* save top of ESTACK */
TRY
push_quantum (END_TAG);
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
}
TI-89 / TI-92 Plus Developer Guide
Appendix A: System Routines — Variables
END_TAG).
— Variable is in-use.
— Reserved or system names cannot be locked
or unlocked.
/* mark end of parameter list */
Not for Distribution Beta Version January 26, 2001