DIRF.
-- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 עַם יִשְׂרָאֵל חַי נֵ֣צַח יִשְׂרָאֵ֔ל לֹ֥א יְשַׁקֵּ֖ר ________________________________________ From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> on behalf of Steve Thompson <ste...@wkyr.net> Sent: Monday, January 8, 2024 11:04 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: allowed characters in member name Why the use of data set names enclosed with apostrophes, that are not TSO oriented? Back in the days when I was doing DOS to MVS migrations, to access certain DOS data sets, you needed this because they could contain names like this: 'PAYROLL STR 12MAY75' for either a Tape label or disk DSN. (where STR was the ID of the company you were doing payroll for -- In various service bureaus I've worked in). DOS did not enforce the same restrictions as OS did (or MVS) for "File names" (DDNAME for OS) UNTIL VSAM (IIRC). VSAM in DOS, as I remember it, did enforce the same naming restrictions. BUT!!! SHARE options were different because VSAM was at the "domain" (O/S) level, for DOS where it is at the address space level for OS. I mention this because there were migrations from DOS to OS{MVS|z/OS) for CICS that did not take this into account and so used multiple FILE names (DDN in MVS terms) and so cause performance issues under MVS-OS390-z/OS if that file is not accessed using a single DDNAME. --- I was just dealing with such a situation with a client where the applications group managment did not want to hear it -- because they didn't want to make the changes that needed to be done. So IAM was brought in which addressed those problems!! Long ugly story. But thought there might be a few that would need this deeper knowledge. Also, back in the day (don't know if this is true to day with zVSE) there was a "dirty" bit set in the VTOC (DIRM if I remember correctly) that caused MVS to see that it may not have space extents correct (forgot the name of the DSCB) and so would re-org the VTOC and maybe the volume (holding a RESERVE) every time DOS would write to such a shared volume where it would set the VTOC dirty bit on. Depending on what was on that volume, that RESERVE could and did affect the DOS and MVS sides. Some of the things we run into today were caused by some decisions made years ago. But as was noted, those names could be cataloged at one time in "MVS". Steve Thompson On 1/8/2024 10:10 AM, Paul Gilmartin wrote: > On Mon, 8 Jan 2024 11:00:38 -0000, Lennie Dymoke-Bradshaw wrote: > >> Using quotes around the DSNAME will allow any combination of Hex chars for a >> Dsname I think (possibly excluding 44X'04' which represents the VTOC). >> However these are not supported for SMS datasets, nor can they be >> catalogued, nor can they be protected by RACF. >> https://www.ibm.com/docs/en/zos/3.1.0?topic=statement-dsname-parameter >> > Where I read such as: > - The system ignores blank characters at the end of a data set name. > > Wouldn't it be better to say, "data set names shorter than 44 ccharacters > are padded with blanks to 44"? > > - Double ampersands to identify a temporary data set name. Note that > if you use apostrophes, DSNAME='&&AB' and DSNAME='&AB' refer > to the same data set. > > That doesn't belong here. It's described better in "Determining Equivalent > JCL". It's incorrect here because it depends on the symbol AB being > undefined. > > "Determining Equivalent JCL" states that double ampersands not enclsed > in apostrophes are reduced to single. Does this suggest that within > apostrophes they are nor so reduced? > > I once tried a DSN enclosed in apostrophes ("unqualified") beginning with > a period. It failed with a syntax error. I have never found this restriction > documented. > > The data set name should not contain the 44 special characters (X'04') > created by hexadecimal editing or any operation that converts the > value of characters to X'04'. > > The "created by ... converts" clause is improperly restrictive. It doesn't > matter how they got there, "converted" or otherwise. > > And no one has mentioned DISABLE(DSNCHECK) before now. > <https://www.ibm.com/docs/en/zos/3.1.0?topic=functions-enabling-disabling-data-set-name-validity-checking> > -- Regards, Steve Thompson ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
