Re: New RFE submitted: Support data structures in CL

Agreed.  I'd nearly always prefer to use an API rather than CL.  Unless I'm doing system management stuff there's no good reason to use CL.  Now, the APIs may take a little work (I just got done learning the ins and outs of QUHDSPH) but that's why we have service programs!!!

On 7/9/2019 12:05 PM, Jon Paris wrote:

Looking at this reminds me of why I prefer to do most everything with RPG ... yuck!


Jon Paris

www.partner400.com
www.SystemiDeveloper.com

On Jul 9, 2019, at 12:33 PM, DrFranken <midrange@xxxxxxxxxxxx> wrote:

One example of the error return area for an API call:

DCL &ERR *CHAR 16 /* Err Information */
DCL &EBprv *UINT 4 STG(*DEFINED) DEFVAR(&ERR 1) /* Err Bytes provided */
DCL &EBavl *UINT 4 STG(*DEFINED) DEFVAR(&ERR 5) /* Err Bytes Available*/
DCL &EEid *CHAR 7 STG(*DEFINED) DEFVAR(&ERR 9) /* Err ID */

Here &ERR is the 'data structure' and the other three are subfields of &Err. Any of the variables can be read or updated and as expected any overlaying field changes as well.

DCL &Cinf *CHAR 112 STG(*BASED) BASPTR(&Cptr) /* Cartridge Info*/
DCL &CID *CHAR 6 STG(*DEFINED) DEFVAR(&Cinf 1 ) /* Cartridge ID */
DCL &VID *CHAR 6 STG(*DEFINED) DEFVAR(&Cinf 7 ) /* Volume ID */
DCL &LIBn *CHAR 10 STG(*DEFINED) DEFVAR(&Cinf 13) /* Tape Libr name*/
DCL &Tcat *CHAR 10 STG(*DEFINED) DEFVAR(&Cinf 23) /* Tape Category */
DCL &Tsys *CHAR 8 STG(*DEFINED) DEFVAR(&Cinf 33) /* Tape System */
DCL &Tden *CHAR 10 STG(*DEFINED) DEFVAR(&Cinf 41) /* Tape Density */
DCL &Cdat *CHAR 6 STG(*DEFINED) DEFVAR(&Cinf 51) /* Change Date */
DCL &Ctim *CHAR 6 STG(*DEFINED) DEFVAR(&Cinf 57) /* Change Time */
DCL &Cloc *CHAR 10 STG(*DEFINED) DEFVAR(&Cinf 77) /* Cartridge Loc */
DCL &ClcI *CHAR 1 STG(*DEFINED) DEFVAR(&Cinf 87) /* Location Ind */
/* ClcI = 0 In tape drive, 1 = Storage location */
DCL &Vst *CHAR 2 STG(*DEFINED) DEFVAR(&Cinf 88) /* Volume Status */
/* Vst = 01-Available, 02-Mounted, 03-not avail, 04-Ejected, */
* 05-Error, 06-inserted, 07-duplicate ID */
DCL &Oid *CHAR 17 STG(*DEFINED) DEFVAR(&Cinf 90) /* Owner ID */
DCL &WP *CHAR 1 STG(*DEFINED) DEFVAR(&Cinf 107) /* Write Prot */
/* WP = 0-NOT Write protected, 1-Write Protected. */
DCL &CIDs *CHAR 1 STG(*DEFINED) DEFVAR(&Cinf 109) /* Cart ID Source*/
/* CIDs = 0-volume ID is CID, 1-System Generated, 2-From Bar Code */
DCL &IEs *CHAR 1 STG(*DEFINED) DEFVAR(&Cinf 110) /* Imp/Exp Slot */
/* IEs = 0-Not in import export slot, 1-import export slot */
DCL &Mtyp *CHAR 2 STG(*DEFINED) DEFVAR(&Cinf 111) /* Media type(BC)*/

Here the data is as DS but it is located in memory where &Cptr (a pointer variable) points it to. So an API returns the base location and a long list of this repeating data. By changing the pointer offset for the data structure &Cinf all of the subfields change as well. This makes the operational code trivial, thus:

DOFOR &Cnum FROM(1) TO(&NCat) /* Loop through all available tapes */
CHGVAR %OFFSET(&Cptr) &Cofs

SELECT

WHEN (&WP *NE '0') THEN(DO)
/* Tape is write protected. Can't consider. */
ENDDO
WHEN (&Vst *EQ '03' *OR &Vst *EQ '04') THEN(DO)
/* Not avail or ejected. Can't consider. */
ENDDO

/* Additional code to consider tapes */

ENDSELECT

CHGVAR &Cofs (&Cofs + &LCat) /* Point to next cartridge *
ENDDO /* End of tape loop */


Does that help or confuse???


- Larry "DrFranken" Bolhuis

www.Frankeni.com
www.iDevCloud.com - Personal Development IBM i timeshare service.
www.iInTheCloud.com - Commercial IBM i Cloud Hosting.

On 7/9/2019 11:52 AM, David Gibbs via MIDRANGE-L wrote:

On Tue, Jul 9, 2019 at 10:48 AM DrFranken <midrange@xxxxxxxxxxxx> wrote:

Don't we get most of this with *DEFINED and *BASED variables and using
includes to pull the definitions in?

Not sure I follow you ... could you post an example?
david

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