There is this rountine assignment
xyz = substr (uvwxyz, 1, 1);
zyx = substr (uvwxyz, 2, 1);
yxz =substr (uvwxyz, 3,1);
The original variable uvwxyz is of $6. Now it is so said (not by the
reference manual) that the length of the three new variables to the left of
the assignment are all determined by that of the original UVWxyz.
So should I use a Length statement to declare the length for them first? Is
this generalizable to many other functions? such as Compress, or just a rule
specific to this substr for a good reason?