Returns TRUE if Ctrl-C was pressed since you last checked, else FALSE.
This only works for programs running on a console, i.e. cli-programs.
Example of how these last three (CleanUp(), FreeStack(), CtrlC())
functions may be used:
/* calculate faculty from command-line argument */
IF r=0 THEN WriteF()('bad args.\n') ELSE WriteF()('result: \d\n',fac(num))
IF FreeStack()() IF n=1 THEN r:=1 ELSE r:=fac(n-1)*n
Of course, this recursion will hardly run out of stack space, and when it
does, it's halted by FreeStack() so fast you won't have time to press
CtrlC(), but it's the idea that counts here.
A definition of fac(n) like:
PROC fac(n) IS IF n=1 THEN 1 ELSE fac(n-1)*n
would be less safe.