Re: Working with IFS files

[Scott Klement <rpg400-l@xxxxxxxxxxxxxxxx>]

>  FilNamPath ='QSYS.LIB/'+ %Trim(inLibrary)+'.LIB/'+
>                           %TRIM(inFile) +'.FILE/' +
>                           %TRIM(inFile) +'.MBR' + x'00';

There are two types of pathnames that can be used in the IFS: Absolute and 
Relative.   A relative pathname starts with whatever the user's current 
directory is, and goes forward from there.

The way the system knows whether you're using a relative pathname or an 
absolute, is that absolute pathnames start with a slash in the first 
character.  So if you had started FilNamPath with the '/' character, it'd 
be an absolute pathname.  Since you didn't, it's a relative pathname.

That means that a user could type CHDIR DIR('/test') and your program 
would add that directory to the start of the pathname. In other words, it 
would look in '/test/QSYS.LIB/whatever.LIB/whatever.FILE/whatever.MBR'. 
If the user typed CHDIR DIR('/QSYS.LIB/MYLIB.LIB') then your program would 
look for the member in 
'/QSYS.LIB/MYLIB.LIB/QSYS.LIB/whatever.LIB/whatever.FILE/whatever.mbr'

Hopefully it's now clear that with the way your code is written, you 
REALLY wanted to use an absolutel pathname not a relative one.  Please 
insert a leading slash into FilNamPath.

Furthermore, your prototype for open() should have options(*string) on the 
first parameter.  Assuming that it does (and therefore is correct), 
there's no reason to add x'00' to the end of the pathname. Adding x'00' is 
just confusing.

>  OpenFlag = O_RDONLY;
>  RC = Open(%Trim(FilNamPath):OpenFlag);

Since you used a VARYING field for FIlNamPAth there's absolutely no reason 
to %trim() it here.

>  TempStmfFile = 'QSYS.LIB/GGPRD.LIB/TMPSTMF.FILE/TMPSTMF.MBR' + x'00';

This has the same problems as FilNamPath.

>  OpenFlag2 = O_CREAT + O_RDWR + O_APPEND + O_TEXTDATA + O_CODEPAGE +
>              S_IWUSR+S_IRUSR+S_IRGRP+S_IROTH;

This isn't legal.  The flags for the file's permissions (or "mode") go 
into a separate parameter from the open flags.

Therefore, you should have:

   OpenFlag2 = O_CREAT + O_RDWR + O_APPEND + O_TEXTDATA + O_CODEPAGE;
   ModeFlags = S_IWUSR + S_IRUSR + S_IRGRP + S_IROTH;

>  RC2=unlink(TempStmfFile);
>
>  RC2 = Open(%Trim(TempStmfFile):OpenFlag2);

Again, there's no need to use %trim().  Also, you need to add the 
ModeFlags parameter. Also, because you specified O_CODEPAGE, you have to 
add the codepage to the parameters.

     RC2 = Open(TempStmfFile: OpenFlag2: ModeFlags: CodePage);

Also, I'm a bit baffled why you'd specify O_TEXTDATA on a file that you're 
just creating now. The system doesn't know what codepage to translate to, 
so the O_TEXTDATA will effectively be ignored.

As to whether it's possible to create a PF this way, I really doubt it. 
You might be able to add a member to an existing PF, but I really doubt 
that you can create the PF itself, the APIs just don't have enough info 
about the file format.

plus, these APIs are really designed for stream files, not physical files. 
So they're not geared up for what you're trying to do.

Is there a particular reason you aren't using RPG's extensive capabilities 
for working with database files instead of trying to use APIs intended for 
stream files?