Re: CHGLIBL woes

[Scott Klement <midrange-l@xxxxxxxxxxxxxxxx>]

Rob,

I think you know this, but aren't thinking about it..   a parameter is 
passed by "reference", which means that what's actually passed under the 
covers is a pointer.

When you do this:

   CHGLIBL LIBL(&ONE &TWO &THREE &FOUR &FIVE)

It's passing 5 pointers.  They point to variables named 'ONE', 'TWO', 
'THREE', 'FOUR', and 'FIVE'.  Five different pointers.  Their strings 
might not be stored consecutively in memory, either.

On the other hand, when you do this:

   CHGLIBL LIBL(&USRLIBL)

You are passing only one pointer -- and therefore only one parameter. 
What's happening under the covers is VERY different from the earlier 
example.

The system doesn't know that you mean to specify a whole list of 
libraries in this case... it thinks, since you only passed one 
parameter, that you have only one library.  And then it thinks you made 
a mistake by passing such a large string, because libraries can only be 
10 characters long, after all.  :-)   That's just the way the computer 
"thinks".

One way to work around this is to call an API like QCMDEXC.  This API 
receives the entire command line as a single string and then has to 
parse it out to get the individual parameter values.  That's the sort of 
thing you're trying to do...


    DCL VAR(&CMD) TYPE(*CHAR) LEN(3000)

    CHGVAR VAR(&CMD)
      VALUE('CHGLIBL LIBL(' *CAT &USRLIBL *TCAT ')')
    CALL PGM(QCMDEXC) PARM(&CMD 3000)

For this to work, there must be at least one blank in between the 
libraries in the list...  If not, you might have to do a little 
manipulation to get some spaces in there.


On 6/18/2013 11:15 AM, rob@xxxxxxxxx wrote:
> I have this simple little test program:
> PGM
> DCL &JOBLIBL *CHAR 2750               /* User part of library list */
> DCL &USRLIBL *CHAR 250                /* User part of library list */
>
> DSPJOB OUTPUT(*PRINT)
> RTVJOBA USRLIBL(&JOBLIBL)
> RTVSYSVAL SYSVAL(QUSRLIBL) RTNVAR(&USRLIBL)
> CHGLIBL LIBL(&USRLIBL) CURLIB(*SAME) /* 1209 */
> DSPJOB OUTPUT(*PRINT)
> CHGLIBL LIBL(&JOBLIBL) CURLIB(*SAME) /* 1211 */
> DSPJOB OUTPUT(*PRINT)
>
> END:
> ENDPGM
>
> > CALL A
>    Value 'QTEMP     ' for parameter LIBL not a valid name.
>    Error found on CHGLIBL command.
>    Function check. CPF0001 unmonitored by A at statement 1209, instruction
>      X'0023'.
>    CPF0001 received by A at 1209. (C D I R)
> ? I
>    Value 'QTEMP     ' for parameter LIBL not a valid name.
>    Error found on CHGLIBL command.
>    Function check. CPF0001 unmonitored by A at statement 1211, instruction
>      X'002F'.
>    CPF0001 received by A at 1211. (C D I R)
> ? D
>
> Results of dump:
>
> Variable               Type        Length         Value
>   *...+....1....+....2....+
> &JOBLIBL                 *CHAR         2750       'QTEMP      QGPL  '
>                                      +26           '  '
>                                      +51           '  '
> ...
> &USRLIBL                 *CHAR          250       'QTEMP     QGPL  '
>                                      +26           '  '
>                                      +51           '  '
> ...
>
>
> Rob Berendt