HP SunSoft Pascal 4.0 manual Simple Types with -xl, Strings of Characters, Pascal procedure

6

The commands to compile and execute SimVar.p and SimVarMain.c

hostname% pc -c SimVar.p hostname% cc SimVar.o SimVarMain.c

hostname% a.out

00000001 00000000 z 9 9 9.9 9.9

The Pascal procedure,

StrVar.p

Simple Types with –xl

With the -xloption, the Pascal real must be paired with a C float, and the Pascal integer must be paired with a C short int.

Strings of Characters

The C counterpart to the Pascal alfa and string types are arrays; C passes all arrays by reference. The C counterpart to the Pascal varying is a structure; C passes structures by value.

Before you call Pascal with a null varying string, set the byte count to zero because that is what Pascal assumes about such strings.

C can pass a structure consisting of a four-byte integer and an array of characters to a Pascal procedure, expecting a var parameter that is a variable- length string.

See the following example:

type

TVarStr = varying [25] of char;

procedure StrVar( var a: alfa; var s: string; var v: TVarStr);

begin

a := 'abcdefghi' + chr(0);

s := 'abcdefghijklmnopqrstuvwxyz' + chr(0); v := 'varstr' + chr(0);

end; { StrVar }

96 Pascal 4.0 User’s Guide