Can I write into a file, for which DISP is defined as SHR?

guruji · New User Joined: 13 Apr 2007 Posts: 44 Location: Bangalore

Hi,
Can I write into a file, for which DISP is defined as SHR?
Thnx,
Reni

expat · Posted: Wed Jul 02, 2008 3:32 pm Post subject:

Have you tried it ?

Itanium · Active User Joined: 22 Jan 2006 Posts: 57 Location: India

It actually depends on how you have defined the file in your Program.

If you have mentioned the file as output or I-O, then you can write.

DISP parameter is specific to the JCL. If the file was created previously, then you can code DISP=SHR and write into that file but you wont have exclusive access to the file.

Its always a good coding practice to write into a file which is created in that step using DISP=(NEW,XXX,XXX).

dick scherrer · Posted: Fri Jul 04, 2008 2:44 pm Post subject:

Hello,

gcicchet · Senior Member Joined: 28 Jul 2006 Posts: 653

Hi,
one other thing to remember is that DISP=SHR will override existing data in the file.

Gerry

dick scherrer

Which may cause some really interesting interaction with another process that also specified shr and is currently going to read the file. . .

FWIW, local standards should prohibit this, and in the case of poor or missing standards, i would surely make sure that nothing i was responsible for supporting used SHR for a qsam output file.

Anuj D.