"Does DCB provide functionality not available via DYNALLOC?" Apples and oranges; they do different things. Don't confuse the DCB macro with things that override DCB parameters. The DCB macro certainly has options that are not relevant to JCL or to dynamic allocation, whether via DAIR, via BPXWDYN or directly via SVC 99, e.g., MACRF. Likewise the have options that are not relevant to the DCB macro.
-- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 ________________________________________ From: IBM Mainframe Assembler List <[email protected]> on behalf of Paul Gilmartin <[email protected]> Sent: Friday, January 26, 2018 10:05 PM To: [email protected] Subject: Re: Fair comparison C vs HLASM On 2018-01-26, at 19:20:02, Jon Perryman wrote: >> Paul Gilmartin wrote: >> Is "full functionality of DCB" useful for any OS other than for z/OS? For >> z/OS, >> allocate with BPXWDYN or JCL DD statement and open by fopen("//DDN:..." ). >> > BPXWDYN is dynamic allocation and does not provide every feature in DCB. > FOPEN allows some DCB parms to be specified as runtime text that is parsed to > fill in a DCB. Neither actually provides all functionality provided by DCB. > Does DCB provide functionality not available via DYNALLOC? BPXWDYN has a poorly documented side door allowing specification of SVC 99 text units by code. >> Paul Gilmartin Wrote: Isn't a PL/X flavor of DCB provided? > There may be DCB in PL/X. The DCB has many fields to be filled in. Does PL/X > require you simply fill in the fields or does it allow abstraction where the > programmer specifies a few parameters and the appropriate fields are filled > in to fulfill the requirements the programmer specified. > How would a mere mortal know any of that? -- gil
