If you have MPEX (<plug> if you don't you should <end of plug>):
 
LISTF file,ACCESS will tell you.
 
We use this all the time.
 
There are two contributions in CSLXL that claim to do this.  (I do not
claim that they don't; I have not used them):
 
 SHOWACC:  List a file's accessors
 
 When  you  need  to  know  who  has a file open,  just run this program.  For
 instance,
 
 :SHOWACC MEMBER.DATABASE.MEMBER
 
 ShowAcc: Show a file's accessors    v1.0    (C) INTEREX 1992
 
 For file: MEMBER.DATABASE.MEMBER          EOF=         32  LIMIT=          32
 _____________________________________________________________________________
 
 Program                    JS Num  User.Account       Reads  Writes   Pointer
 
 QUICK.CURRENT.COGNOS      ,S   166,ENTRY.EVENTS         20       1         1
 _____________________________________________________________________________
 
 Works with IMAGE files and most standard MPE files.  Does not seem to work
 with message files.
 
Leonard Berkowitz
RIA Group (Warren, Gorham & Lamont)
 
from LISTACCT.DOC.CSLXL:
 
Description   : LISTACC will list a fileset's accessors. Specifically,
                 for each process accessing a file, it will list:
                    1) Program name
                    2) Job/session number
                    3) Its PIN number
                    4) Its corresponding Jobname, User name & Account
name
                    5) The number of reads, writes, and the current
                       position of the file pointer
 
                 LISTACC can only give limited information on circular,
                 message, and relative I/O files. LISTACC is adapted
from
                 SHOWACC written by John Sullivan of INTEREX.
 
 
______________________________ Reply Separator _________________________________
Subject: Question regarding file access
Author:  Brian Peterson <[log in to unmask]> at Internet-Exchange
Date:    08/18/96 6:04 PM
 
 
is there a way to tell what program is accessing a particular file when
its in use? for example, if i do a LISTF filename,2 and note that the
file is being accessed, can i tell what program is holding it?
 
i'm using MPE 4.0. (i will be installing 5.0 soon)
 
--
Brian
[log in to unmask]
"Its all just 1's and 0's"