String Parameters of Various Lengths, Take Two

June 12, 2002 Timothy Prickett Morgan

Dear Readers:

Several people have written to point out errors in my solution to the reader who wanted to make an RPG subprocedure accept character parameters of any size. I need to correct the code that I provided in that issue of Midrange Guru, OS/400 Edition. (I plan to explore this topic more and to present the ideas of my respondents in the near future, so watch for more information in a future edition of Midrange Guru.)

Here is the original question”

“I have an RPG IV subprocedure that I call from several different programs. I use what I call the QCMDEXC method to pass a character string to it. That is, I pass two parameters–the character string and the length of the character string. I would like to eliminate the second parameter.”

I failed to explain that the subprocedure needed to modify the string parameter. I made the mistake of including the CONST keyword on the string parameter while testing, but forgot to remove it before publication. As my demo subprocedure did not modify the string, the compiler did not catch my error.

Here is the proper code (I hope).

First, the procedure prototype:

D MyProc          PR                  Opdesc            
D   String                   32767    Options(*Varsize)

Next, the subprocedure:

H nomain                                                
                                                         
  /copy copysrc,myproc                               
  /copy copysrc,ceedod                                   
                                                         
 P MyProc          B                   Export            
  * Procedure Interface                                  
 D                 PI                  Opdesc            
 D   String                   32767    Options(*Varsize) 
                                                         
  * Variables for the CEEDOD API                         
 D DescType        s             10I 0                   
 D DataType        s             10I 0                   
 D DescInfo1       s             10I 0                   
 D DescInfo2       s             10I 0                   
 D DataLen         s             10I 0                   
                                                   
 * Retrieve the length of the string parameter            
C                   Callp     CEEDOD(1: DescType:         
C                                DataType : DescInfo1:    
C                                DescInfo2 : DataLen :    
C                                *OMIT)                   
                                                          
 * DataLen now contains the length of the input string    
                                                          
                                                          
 * Do whatever needs to be done                           
                                                          
C                   Return                                
P                 e                                       

I apologize for the error.

— Ted

Sponsored By ADVANCED SYSTEMS CONCEPTS

SEQUEL meets all your iSeries and AS/400 data access needs in a single, integrated solution: Windows, Web or host user interfaces Convert AS/400 data into PC file formats E-mail or FTP query results, reports and spool files Run-time prompted queries and reports for end users IF-THEN-ELSE logic in queries and reports Report, form and label formatting second to none Easily convert date fields, character-to-numeric, numeric-to-character and other data manipulation SORT or JOIN using a calculated field Quick summarization of data with Tabling function Run multiple SEQUEL requests as one with the SEQUEL Scripting function OLAP Business Intelligence at a fraction of the cost of comparable solutions Take 6 minutes to view a SEQUEL ViewPoint ScreenCam movie to see how simple Windows-based AS/400 and iSeries data access can be! In just a few short minutes, you can find out ways to make your job easier and improve data access throughout your organization. Download the ViewPoint movie here . For more information or a FREE trial of SEQUEL, call 847/605-1311 or visit Advanced Systems Concepts .