> On 2 Jan 2025, at 1:37 am, Charles Mills <[email protected]> wrote: > > On Tue, 31 Dec 2024 12:10:36 -0600, Paul Gilmartin <[email protected]> > wrote: > >>> - Does C do mainframe record I/O? C doesn't do any I/O at all, but the >>> IBM-supplied C library has excellent support for records, VSAM, pipes, >>> etc., etc. You can read all about it in the Programming Guide. >>> >> Can files of those formats be allocated to DDNAMEs and processed >> by traditional access methods such as QSAM, like FILEDATA=RECORD? > > The Programming Guide is the authoritative source of information. > > I am not a pipes expert but does DD allocation of pipes even make sense?
You can use named pipes in JCL. Under the covers QSAM calls the BPXnWRT callable services. The DB2 load utility supports named pipes so you load tables without having to have data at rest in the form of a data set. > For VSAM. BPAM and QSAM, yes, the C I/O model supports access by DS name or > by DD name. You can read all about it in the P/G. > > I don't understand the QSAM question. Does the C library use QSAM under the > hood? Or some sort of roll-your-own with BSAM or EXCP? No idea. If you specify “noseek” it uses QSAM and defaults to “BSAM” so you can use fgetpos/fsetpos efficiently. > > Or do you mean "if you write a file with the C library, can you read it with > assembler QSAM?" Yes, absolutely. > > CM > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
