On Mon, 13 Feb 2017 09:44:51 -0600, John McKown wrote:
>
>> 3. Is it possible to have the Assembler routine place the extracted data
>> into a unix
>> pipe or a C type=memory file and then i can retrieve it ?
>
>You can call the UNIX BPX* routines from COBOL, so you can use something
>like BPX1PIP to create an unnamed pipe. The COBOL program could then pass
>the "write_file_descriptor" to the HLASM program as a parm. The COBOL
>program would use BPX1RED to read from the read_file_descriptor. The HLASM
>
Is this better than using BPXWDYN('ALLOC ...') the descriptor and using
conventional COBOL I/O)?
>would use BPX1WRT to write to the passed in descriptor. But critically
>important is that the HLASM program must be ATTACHX'd (BPX1ATM service can
>do this) and not LINK'd to (as a normal COBOL CALL would do). Otherwise
>
Does BPX1ATM dup() descriptors as spawn() does? If so the parent must
close() its copy of the input descriptor or it never sees EOF. Happens to
me all the time.
>you'll most likely get a lock out with either the TCB either waiting in the
>COBOL code for the HLASM to write some thing, or in the HLASM code waiting
>(buffer full) for the COBOL to read something. I just wanted to throw this
>last in for completeness. You might also need some way to communicate to
>the COBOL routine that the HLASM routine has written an "EOF" and has ended.
>
close() the input end of the pipe should suffice. COBOL should see EOF.
On Mon, 13 Feb 2017 16:45:33 +0100, Peter Hunkeler wrote:
>
>Any you'd need to run the Cobol and the assembler routine in parallel, not as
>main routine calling a subroutine. UNIX pipes need both ends to be acitve for
>them to work.
>
I've sometimes cheated on this, mostly with stderr, assuming that
any error messages will fit in a 131KB buffer. Hard to handle both
stdout and stderr otherwise in a Rexx parent. Is there a select()
SYSCALL?
-- gil
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