MVS and z/OS DD parameters made easy - M114

how to work with DISP,DCB,SPACE and other DD related parameters

[lavaq]

It's so funny! I'm watching this video almost a year and a half after you posted it. It appears that WA6OUR is a licensed amateur "Ham" radio call sign!

[vmisev]

​Thanks for the video! I had to watch it again and again just to make any sense of it :)
You are explaining things wonderfully; it's just that subject is quite complicated, absolutely everything is totally diff from what I know, and old dog learning new tricks thing :D

All of this Big Blue stuff made me think and realize just how revolutionary simple and user-friendly DEC VMS was back then (I started w VMS in '91 and it was easy-peasy, but I was young ;) )

All best!

[grigorytrenin]

'dd' Unix command was originally intended to convert between EBCDIC/ASCII, blocked-records/byte-stream, big-endian/little-endian, i.e. between IBM and DEC worlds.

It was ironically named 'dd' and given a weird syntax (if=FILE ibs=BYTES) to resemble JCL.

$ dd
^C
0+0 records in
0+0 records out

It says "records" - you see? :)

[jms]

To be fair open() takes flags like O_CREAT and friends give you control over whether a file is created, truncated or must (not) exist beforehand. Bourne shell’s noclobber option provides some control too. One occasionally useful trick is to open a file and immediately remove it. Think of it as an uncatalogued file that ceases to exist when you drop the handle or exit for whatever reason. Finally many editors inform of background file modification promptly and can reload automatically . Being told only at attempted save is a poor show. Absolutely finally you will find tampering with a running executable somewhat more difficult though for some reason shared objects in use don’t get the same protection

[viataculouie]

Nice video thank you!
I work as a programmer on the mainframe and I use this daily.
You don't want people to be lazy? That's why you don't mention BLKSIZE=0?

[EdouardTavinor]

I think vi makes a temporary copy of the file you edit with it (probably in /tmp). i recently had a problem where I got a json file 27GB in size and i wanted to delete a { and a } from the start and end of the file and split the file into 50 MB chunks (while conserving json syntax). I ended up writing a program in go to do it---vi, ed etc. all refused to open the file :/

[stonent]

I believe the command you were looking for is CAT. TYPE is for DOS. :)

[Stosszahlansatz]

Is the DCB stored both in the catalog and the VTOC?
At 35:55, we can see like a record below the data set information. Is this the VTOC entry?

[vikramavirneni]

Hi

Can you please share mainframe Testing training videos

[patrickstival]

Hello moshix. I was wondering if you can help me understand how to connect to a mainframe throught a 3270 terminal to screen scrape it under SSL encryption. Can I get your e-mail?