Getting member information into a database file

I'm trying to write a program that will take the source physical file name and library name as parameters and deliver all the members that are available in the SRCPF, and the type and attributes of the members. The problem is that a source physical file cannot be read. On doing runqry, it details only the first member listed.
There is a complicated way of doing this and a simple way. The complicated way uses User Spaces and APIs, and is faster in execution than the simple method, which I describe below.

You can get member information into a database file using DSPFD. Example:

DSPFD FILE(QCLSRC) TYPE(*MBRLIST) OUTPUT(*OUTFILE) OUTFILE(QTEMP/LISTFILE)

This creates LISTFILE in QTEMP, or, if it already exists, replaces the previous contents. The file will contain one record for each member in QCLSRC. The record format has the following structure (I have marked the fields you are most interested in with *) : 

 Format QWHFDML "DSPFD format for TYPE *MBRLIST" 

    1    1    1A MLRCEN     Retrieval century:  0=19xx, 1=20xx           
    2    7    6A MLRDAT     Retrieval date: year/month/day               
    8   13    6A MLRTIM     Retrieval time: hour/minute/second           
   14   23   10A MLFILE     File                                         
   24   33   10A MLLIB      Library                                     
   34   34    1A MLFTYP     P=PF, L=LF, R=DDM PF, S=DDM LF               
   35   38    4A MLFILA     File attribute: *PHY or *LGL                 
   39   41    3A MLMXD      Reserved                                     
   42   47    6A MLFATR     File attribute:  PF, LF, PF38, or LF38       
   48   55    8A MLSYSN     System Name (Source System, if file is DDM)       
   56   57  3,0P MLASP      Auxiliary storage pool ID:  1=System ASP         
   58   61    4A MLRES      Reserved                                         
   62   64  5,0P MLNOMB     Number of members                                 
*  65   74   10A MLNAME     Member                                           
*  75   80 10,0P MLNRCD     Current number of records                         
   81   86 10,0P MLNDTR     Number of deleted records                         
   87   92 10,0P MLSIZE     Data space and index size in bytes, -1=See MLSIZ2 
   93   96    4A MLSEU      Source type for S/38 View as it appeared on S/38 
   97   97    1A MLCCEN     Member creation century: 0=19xx, 1=20xx           
   98  103    6A MLCDAT     Member creation date: year/month/day           
  104  104    1A MLCHGC     Last change century: 0=19xx, 1=20xx           
  105  110    6A MLCHGD     Last change date: year/month/day               
  111  116    6A MLCHGT     Last change time: hour/minute/second           
* 117  166   50A MLMTXT     Text 'description'                             
* 167  176   10A MLSEU2     Source type                                   
  177  177    1A MLUCEN     Last Used Century: 0=19xx, 1=20xx             
  178  183    6A MLUDAT     Last Used Date: year/month/day                 
  184  186  5,0P MLUCNT     Days Used Count                               
  187  187    1A MLTCEN     Usage Data Reset Century: 0=19xx, 1=20xx       
  188  193    6A MLTDAT     Usage Data Reset Date: year/month/day       
  194  201 15,0P MLSIZ2     Data space and index size in bytes           
  202  202    1A MLSTFR     Member storage freed Y=Yes                   

(NOTE:  This is in V5R2 of OS/400  --  the fields may be different at other operating system levels.) 

You can now use a CL or RPG program to read this member list and do what you want with the information. 

To open a source member in a program, use OVRDBF to override the program name of the file (MYSRC, for example) to the actual name & library of the source file, and the MBR parameter will be the name of the member you want to open. 

Declare the file in your F-specs as PROGRAM DESCRIBED, not externally described. The record length can be greater than the actual length you expect (remember that ILE source files have record lengths of 112 bytes). 

Create I-specs to describe the fields as follows: 

    1    6  6,2S SRCSEQ                (Source sequence number) 
    7   12  6,0S SRCDAT                (Source change date) 
   13  112  100A SRCDTA                (Source line)

==================================
MORE INFORMATION ON THIS TOPIC
==================================

The Best Web Links: tips, tutorials and more.

Visit the ITKnowledge Exchange and get answers to your developing questions fast.

Ask the Experts yourself: Our application development gurus are waiting to answer your programming questions.

This was first published in April 2005

Back to top