[netrexx-pipelines] Restart do loop from catch in pipes

[ColinK <ibm...@im...>]

I am working on creating the NetRexx pipeline filter that mimics the 
VM/CMS filter HOSTBYNAME and I have run into a problem that I am not 
sure how to get around (perhaps partly because I am not very Java savvy).

When a hostname is passed to the routine that cannot be resolved an 
UnknownHostException is thrown.  I can catch this (in fact I have to 
catch it since it is a checked exception) and handle it but how do I get 
back up into the main forever loop to process the next input record?  It 
seems that once I am in a catch section the stage collapses. The Rexx 
iterate statement does not work since it is not in the first 
‘instructionlist’ section.

    do
       loop forever
          . . . peekto…
          . . . process input record  . . .
          . . . output. . .
          . . . readto. . .

       catch UnknownHostExceptiom
           do
           . . . handle problem. . .
           . . . output. . .
           . . . readto. . .
           . . . << here I want to head up to forever loop to do next
    record>>. .

           catch StageError

           end /*do UnknownHostException */

       catch StageError

       end /*do loop forever */


It would be interesting to see how a real VM/CMS system handles the 
following:

    pipe "(end ?) literal
    www.shaw.ca;dns.google;bogus.bogus;www.google.ca | split string /;/
    | h: hostbyname | console

    pipe "(end ?) literal
    www.shaw.ca;dns.google;bogus.bogus;www.google.ca | split string /;/
    | h: hostbyname | console ? h: | insert ,Bad: , BEFORE | console"


Right now my grand attempt pumps out the following:

    Z:\NetRexx-3.08-GA\bin>pipe "(end ?) literal
    www.shaw.ca;dns.google;bogus.bogus;www.google.ca | split string /;/
    | h: hostbyname | console
    23.6.246.208
    8.8.4.4 8.8.8.8
    Input record  3: Unable to determine IP address for bogus.bogus

    Z:\NetRexx-3.08-GA\bin>pipe "(end ?) literal
    www.shaw.ca;dns.google;bogus.bogus;www.google.ca | split string /;/
    | h: hostbyname | console ? h: | insert ,Bad: , BEFORE | console"
    23.6.246.208
    8.8.4.4 8.8.8.8
    Input record  3: Unable to determine IP address for bogus.bogus

Note that the 4th hostname does not appear to be processed.

Is there some kind of trick in handling this scenario.

Thanks.
Colin