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cstringpascal

OpenvVMS passing array of char argument to C-function from pascal

I wrote the next Pascal code

PROGRAM demo1 (OUTPUT);
%include "sqlr$include:sqlrdef.pas"
VAR
    query : VARYING [50] OF CHAR;
BEGIN
    query:= "select * from countries";
    sqlr$test (query);
END.

"sqlrdef.pas" file consist

[EXTERNAL] FUNCTION sqlr$test (data : string) : INTEGER; EXTERNAL;

sqlr$test it is a C-function

unsigned long SQLR$TEST (char *data)
{
    printf ("data is [%s] \n", data);
    return SQLR$_NORMAL;
}

But when I execute my program on Pascal, I get the next output

data is []

What do I need to change for passing the argument to C-function from Pascal correctly?

Solution

  • You should use

    %stdescr query_dsc : [CLASS_S] PACKED ARRAY [$L1..$U1: INTEGER] OF CHAR

    and

    query : PACKED ARRAY [1..40] OF CHAR VALUE 'select * from countries';