Prevent clearing function from memory
mlock locks the currently running function in memory so that subsequent clear functions do not remove it. Locking a function in memory also prevents any persistent variables defined in the file from getting reinitialized.
Use the munlock function to return the file to its normal, clearable state.
The function testfun begins with an mlock statement.
function testfun mlock . .
When you execute this function, it becomes locked in memory. You can check this using the mislocked function.
testfun mislocked('testfun') ans = 1
Using munlock, you unlock the testfun function in memory. Checking its status with mislocked shows that it is indeed unlocked at this point.
munlock('testfun') mislocked('testfun') ans = 0