RECFM, LRECL and BLKSIZE are more application issues than DASD geometry issues. IBM had it right on TSS, where normal volumes were page formatted and all access methods dealt with 4 KiB blocks regardless of DCB attributes or DASD geometry. Same for VSAM; there's nothing in your ACB attributes that depends on geometry/
-- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 ________________________________________ From: IBM Mainframe Discussion List [IBM-MAIN@LISTSERV.UA.EDU] on behalf of Charles Mills [charl...@mcn.org] Sent: Friday, January 7, 2022 9:25 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: ... Re: Top 8 Reasons for using Python instead of REXX for z/OS Wait a minute! RECFM and JCL are different problems. You could write a marvelous modern replacement for JCL but if you were going to deal with "3390" (note the quotation marks) DASD you would need RECFM, LRECL and BLKSIZE (or, if you prefer, RecFormat, RecLen and BlockSize). And JCL can be used to reference zFS files, and then RECFM, etc. pretty much goes away, even if the rest of JCL does not. I'm not defending either one; just saying they are separate problems. Charles -----Original Message----- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of David Crayford Sent: Friday, January 7, 2022 12:03 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: ... Re: Top 8 Reasons for using Python instead of REXX for z/OS On 7/1/22 12:33 pm, Matt Hogstrom wrote: > I would not describe JCL as a programming language anymore than a pom is a > language. Maven uses the pom XML to describe actions, dependencies and based > on its analysis actually does the execution. And the declarative nature of pom.xml is why people have shifted from Maven to Gradle which is basically a groovy DSL where you can drop down into scripting. Same as a Jenkins with the Jenkinsfile, you can choose to use Groovy if you want to add logic. JCL sucks! We know it sucks but there is nothing we can do about it other than suck it up and crack on. Try and teach a new hire about a DCB with cylinders and tracks and RECFM, LRECL, BLKSIZE etc. It's no wonder they prefer the file system. > Not a great comparison but I think it is consistent with JCL being a set of > directives that are interpreted and acted upon as opposed to being an > execution engine. I think its does a fine job for what it is for in terms of > abstraction of data from programs, allowing serialization via JES and dynamic > allocation, etc. It describes a unit of work. > > Matt Hogstrom > m...@hogstrom.org > +1-919-656-0564 > PGP Key: 0x90ECB270 > Facebook <https://facebook.com/matt.hogstrom> LinkedIn > <https://secure-web.cisco.com/1ikTc5zH6uwsKXY0p77X8UpOQBPfIzoi6imGkcsMGFxi20yCDEDk3qScKWn1DQlCMX_jU3FNo58p4vhonr-Ert8jBRMVYTl1yxUidAynF3tD9r8AeQ9Ex7kX5ekopX6l3TqlhvDPm7OR7LUSrWhkPKS8RJ2BmlVUhoIP5PC62LG-0vrrmisXZjTAHebv-RNSf784OHEzZ15yDhGiSyS2mDQiNf08QgXKlpT_Pc3wmoeG0QPFCN6laTogKjrdVyFU6u__RjuV2KfRIrgJtj_ejtnJx3FtNf9sO9KdnQXXse0tAhz6yV-PN75XlapiukKGGQ2YYMuLYzJovwuhiH8oAUlkDZK2BE6rmaccpuQHm6_9l-f07UX_4UBGVkXU-DTcJSFNIwwkAKJRxlp4FsfWJ5AbobDIU3bkv2qEv-DOojoo/https%3A%2F%2Flinkedin%2Fin%2Fmhogstrom> > Twitter <https://twitter.com/hogstrom> > > “It may be cognitive, but, it ain’t intuitive." > — Hogstrom > >> On Jan 6, 2022, at 10:05 PM, Andrew Rowley <and...@blackhillsoftware.com> >> wrote: >> >> On 7/01/2022 12:23 pm, David Crayford wrote: >>> I understand that it's declarative. But it has logic such as IF/THEN. That >>> is no reason why it couldn't have been a scripting language like CL on >>> AS/400. >>> >> IF/THEN was a late addition, and is probably one of the biggest problems >> with JCL because it doesn't work like IF/THEN in a programming language. >> IF/THEN is really a property of the enclosed steps (I suspect it generates >> the same thing as equivalent COND statements on the steps) rather than a >> logical block in the JCL. >> >> e.g. from the JCL reference: >> >> The system processes the following statements regardless of the logic of the >> IF/THEN/ELSE/ENDIF >> statement construct. They can be placed in a THEN or ELSE clause, but they >> are not executed >> conditionally. >> • PROC and PEND statements >> • JES2 and JES3 statements and commands >> • JCL command statements >> • Comment (//*) statements >> • INCLUDE statements >> • Delimiter (/*) statements >> • Null statements >> • SET statements >> >> The IF/THEN/ELSE/ENDIF statement construct does not conditionally control >> the processing of JCL; rather, it conditionally controls the execution of >> job steps. >> >> >> -- >> Andrew Rowley >> Black Hill Software >> >> ---------------------------------------------------------------------- >> 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 ---------------------------------------------------------------------- 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 ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
