Re: Prototype Calls

[rob@xxxxxxxxx]

I used to use system() and thought the ease of using it was delightful.

However there is an item that got be back to qcmdexc.  The error handling. 
 Don't get me wrong, system() has some error handling that will work for a 
majority of the time.  Sample usage.

I have
      /INCLUDE ROUTINES/QAPISRC,SYSTEM
which contains
      * Execute Command (system) Subprocedure Variables
     D System          PR            10I 0 ExtProc('system')
     D  CmdText                        *   Value Options(*String)      
Command text string

     D ErrorCPF        S              7A   Import('_EXCP_MSGID')      
Error number
     D ErrorFlag       S             10I 0 Inz(0)      Error flag

and in my usage I may have:
C                   Eval      ErrorCPF=Blanks 
C 
C                   Eval      ErrorFlag=system(cmd)
C                   If        ErrorFlag<>0 
C                   Select 
C                   When      ErrorCPF='CPF1111' 
C*                  ... 
C                   When      ErrorCPF='CPF2222' 
C*                  ... 
C                   Other 
C*                  ...
C                   EndSL 
C                   EndIf 

Now, that's not bad.  But, getting back to qcmdexc.  The problem is that I 
couldn't see the error message data.  For example if CPF1111 had the name 
of an object that it couldn't manipulate there was no way to access that 
with system().
So I have:
      /INCLUDE ROUTINES/QRPGLESRC,PSDS
which contains
     DMYPSDS          SDS
     D PROC_NAME         *PROC                   * Procedure name
     D PGM               *PROC                     Program name
     D PGM_STATUS        *STATUS                 * Status code
     D PRV_STATUS             16     20S 0       * Previous status
     D LINE_NUM               21     28          * Src list line num
     D ROUTINE           *ROUTINE                * Routine name
     D PARMS             *PARMS                  * Num passed parms
     D EXCP_MSG               40     46
     D EXCP_TYPE              40     42          * Exception type
     D EXCP_NUM               43     46          * Exception number
     D PGM_LIB                81     90          * Program library
     D EXCP_DATA              91    170          * Exception data
     D EXCP_ID               171    174          * Exception Id
     D PGM_DATE              191    198          * Date (*DATE fmt)
     D PGM_YEAR              199    200S 0       * Year (*YEAR fmt)
     D LAST_FILE             201    208          * Last file used
     D FILE_INFO             209    243          * File error info
     D JOB_NAME              244    253          * Job name
     D WSID                  244    253            Workstation ID
     D USER                  254    263          * User name
     D JOB_NUM               264    269S 0       * Job number
     D JOB_NUMA                       6A   overlay(JOB_NUM)      * Job 
number, alpha
     D JOB_DATE              270    275S 0       * Date (UDATE fmt)
     D RUN_DATE              276    281S 0       * Run date (UDATE)
     D RUN_TIME              282    287S 0       * Run time (UDATE)
     D CRT_DATE              288    293          * Create date
     D CRT_TIME              294    299          * Create time
     D CPL_LEVEL             300    303          * Compiler level
     D SRC_FILE              304    313          * Source file
     D SRC_LIB               314    323          * Source file lib
     D SRC_MBR               324    333          * Source file mbr
     D PROC_PGM              334    343          * Pgm Proc is in
     D PROC_MOD              344    353          * Mod Proc is in


       call qcmdexc(parm:parmlen);
       // at this point you can check the psds fields for error
       // PSDS = Program Status Data Structure - look it up
       Select;
       When excp_id=*blanks;  // ok
        // ok
       When excp_id='CPF1234';
        // SAMPLE
         Select;
         When %subst(excp_data:1:10)='MYLIB';
           // Do this or that
         EndSl;
       Other;
       EndSl;


If you want to get really detailed with command execution, like maybe 
prompting a command before executing it, and much more, check out the api 
QCAPCMD.


Rob Berendt
-- 
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