On 9/10/2020 3:09 PM, Stanislawski, Shawn (National VM Capability) wrote:
> Anyone have a great idea on how to use PIPE to replace single record
> at a specified record number in a file without having to read /
> write out the entire file, with the following caveats?
>
> * the file could be either recfm FIXED or VARIABLE
> * the new record could potentially be either shorter or longer than its
> original
If you want to pad or truncate as needed, probably the simplest way is
to convert V2C and then back C2V. Assuming the input is numbered for
DISKUPDATE:
(end /) ...
| in: fanout
| chop 10
| copy
| diskrandom fn ft fm
| xlate 00-ff 40
| out: specs 1-* v2c 11 select 1 1.10 1 11-* 13
| specs 1.10 1 11-* c2v 11
| diskupdate fn ft fm
/ in:
| out:
I was always a little disappointed that COMBINE wouldn't truncate and
the f2V conversions wouldn't pad. And speaking of V format, I don't
think I ever got around to complaining about this error way back:
> pipe literal 123| specs 1-* v2c 1.2 | cons
> Output field too short to contain field length.
> ... Issued from stage 2 of pipeline 1.
> ... Running "specs 1-* v2c 1.2".
> Processing item number 1: 1-* v2c 1.2.
The message is wrong, since 2 is just long enough to contain the field
length, but even if I asked for only one character I don't get why this
is an error. V2B and V2X don't care if there's room for the output; why
should V2C?
Uh-oh. I must never have tried THIS before:
> pipe literal 123| specs 1-* v2c 1.3 right | cons
> 1
That's just wrong.
¬R
