When passing parms by value, they can only be used as IN values, whereas
pass by reference is used for IN/OUT.... Value makes the parm "read
only", like CONST.
Eric DeLong
-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx
[mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of James Lampert
Sent: Tuesday, November 25, 2008 5:14 PM
To: rpg400-l@xxxxxxxxxxxx
Subject: Calling C from RPG: what am I doing wrong?
I have a C procedure called by an RPG program:
In the RPG program, it is prototyped thusly:
D FOO PR EXTPROC('foo')
D * VALUE OPTIONS(*STRING)
D * VALUE OPTIONS(*STRING)
D 10I 0 VALUE
D * VALUE OPTIONS(*STRING)
D * VALUE OPTIONS(*STRING)
and called thusly:
C CALLP FOO(X,Y,I,K,BUFFY)
and the C procedure is:
int foo(char *opcode, char *filename, int len, char *key, char *buffy) {
/* here we read a record from a file, putting the record into buffy */
A printf() statement in the C procedure tells me that the record
definitely gets read from the file, and it's definitely the right
record. Yet when control returns to the calling program, the record is
gone, and what was originally in BUFFY is back.
Obviously, I'm doing *something* wrong here.
--
James H. H. Lampert
Touchtone Corporation
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