HP SunSoft Pascal 4.0 - Manual (Page 97)

Program Construction and Management 73
4
By default, both definitions of variable x are public . Thus, when you compile
and link the program and module units, references to x refer to the same
variable, as follows:
If you compile the program giving the -xl option, the variables are private
by default, as follows:
You can get the same effect by explicitly declaring the variable in a private
var section. Similarly, when you use -xl , you can create public variables by
declaring them in a public var section.
As with routine declarations, it is often a good idea to declare public
variables in an include file. Doing so makes it easier to keep your
declarations consistent.
There are other methods for making variables visible to different units. See
Chapter 5, “Separate Compilation,” for more information.
hostname% pc program_unit3.p module_unit3.p
program_unit.p:
module_unit.p:
Linking:
hostname% a.out
Hello, world for the 1 time.
Hello, world for the 2 time.
Hello, world for the 3 time.
Hello, world for the 4 time.
Hello, world for the 5 time.
hostname% pc -xl program_unit.p module_unit.p
program_unit.p:
module_unit.p:
Linking:
hostname% a.out
Hello, world for the 0 time.
Hello, world for the 0 time.
Hello, world for the 0 time.
Hello, world for the 0 time.
Hello, world for the 0 time.