>>I cannot use a program of this type.
>>
>>On my framework:
>>CD,SET DEFAULT ...
>>
>THEY ARE FORBIDDEN !!!
>
>What's the reason for such restriction?

CD is a global setting, like a public variable,
you can set/get it with various commands,
but it is a public value nothing more, nothing less.

If you remove the commands of writing, it becomes a public constant.

It doesn't now serve to be a genius for to understand,
that a constant doesn't couple the states of two separate procedures,
but a variable yes.

This is the motive for which the use of public variable is dissuaded.

But if everybody dissuades the use of public variable,
why then it is used with so much superficiality
the public variable defined in the system of development?

If during the change of the current directory
is executed some other code,
and this depends on the value of the current directory?

If one wants to write a program with few bugs and easily modifiable it owes:
- to use few coherent schemes
- uncouple the states the more possible.

Other in Message #1043867