On Sat, 14 Nov 2020 08:34:15 +1100, Andrew Rowley wrote: >On 14/11/2020 12:54 am, Kirk Wolf wrote: > >> The new commands (getpds and putpds) use BPAM+BSAM along with our existing >> Co:Z record <-> stream processing framework to allow you to copy PDS >> members to and from z/OS UNIX files. Also included are extensive options >> for ISPF stats processing. >> > >Nice work. I have immediate uses for it. > >One question, I see the options: > >rdw >preceed lines with a four byte IBM-style RDW, consisting of a two byte >network order (big endian) length, followed by two bytes of zeros. > >l4 >preceed lines with a four byte network order (big endian) length of the >record that follows. Note: Unlike the rdw option, this length value does >not include the size of the length field. > >If you are looking at a file, how would you know whether the length >field is included in the record length? > >The common practice seems to be that the length value in the RDW >includes the length of the RDW itself. This is observed by other >products e.g. FTP. Is there a reason to have the option to exclude the >RDW length? > Except for UNIX files. From Using Data Sets: Record Processing for UNIX Files
When a file is accessed as record-oriented (with FILEDATA=RECORD), your program does not see the record prefixes. The PUT macro adds a prefix to each record in the same format as with BSAM or QSAM. A GET macro removes the prefix. Each record prefix is mapped by the IGGRPFX macro. It is the following four bytes: Offset Length Symbol Description 0 1 RPFX00 Reserved. 1 3 RPFXLLL Length of record that follows this prefix. (FSVO "same".) >The whole RDW/record length concept causes a lot of confusion - even it >seems in IBM. Requiring people to choose what type of length field will >add to the confusion. > The wonderful thing about standards is that you get to pick from among several the one you want! -- gil ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
