sas, any function to test if a file is locked ?

1. Using the SCL LOCK Function

My goal is to have one SAS session lock all other SAS sessions out of a
particular SAS table while it needs to work with it. I want to be able to
lock the table, then open it with the OPEN function (in update or input
mode), run data steps that read the table, run data steps that update the
table, run PROC APPEND to update the table, etc, etc. Then finally unlock
the table when done.

rc = LOCK('mylib.mytable','LOCK');
...
...
dsid = OPEN('mylib.mytable','I');
...
...
dsid = OPEN('mylib.mytable','U');
...
...
SUBMIT CONTINUE;
   DATA work.newtable;
      SET mylib.mytable;
      ...
   RUN;
ENDSUBMIT;
...
...
SUBMIT CONTINUE;
   DATA mylib.mytable;
      SET work.othertable;
      ...
   RUN;
ENDSUBMIT;
...
...
ETC, ETC, ETC
...
...
rc = LOCK('mylib.mytable','CLEAR');


This seems to work with some initial testing. However, I'm wondering if
there are any cases where this technique would not work (i.e. where this
session would lock itself out of the table somehow, or where the LOCK
function somehow would not lock out other users).

One situation I can think of where this would not work is if I did a remote
submit. The remote session would be locked out of the table when it finds
that the table is locked, even though the remote session corresponds to
this user.

Other than that are there any problems with this approach? I don't see alot
of info in SAS Help about how exactly the LOCK function works.

Thanks

2. Simple question about locking variable class in Wilcoxon rank sum test

3. Known bug: LOCK dataset QUERY does not detect locks from other

So the LOCK statement is not able to detect locks from other processes,
even though there is a QUERY/LIST option supplied just for that purpose.
Problem Notes 6029 and 2859 list this as a known bug, one which isn't
fixed on Solaris.

Per note 6029, the only workaround is to attempt to place a lock, and
check for an error condition.  Since I run all my scheduled jobs with
ERRORABEND I don't find this terribly helpful.

Shockingly, Google turned up NO discussion of the matter anywhere,
including SAS-L.  Is there anyone else out there who has been burned by
this?  How did you end up dealing with it?

Using 'touch'/FILEEXIST/etc to roll my own lock indicators is always an
option, but that seems a bit silly; and I'm trying to keep the amount of
Stupid Unix Tricks to a bare minimum, out of consideration for those who
come behind me.


LOG sample:

17         lock skippy.lms_2005_20080603 query;
NOTE: SKIPPY.LMS_2005_20080603.DATA is not locked or in use by you or
any other users.

20         lock skippy.lms_2005_20080603;
ERROR: A lock is not available for SKIPPY.LMS_2005_20080603.DATA, lock
held by process 15711.

23         lock skippy.lms_2005_20080603 query;
NOTE: SKIPPY.LMS_2005_20080603.DATA is not locked or in use by you or
any other users.

26         lock skippy.lms_2005_20080603 clear;
ERROR: SKIPPY.LMS_2005_20080603.DATA is not locked by you.

29         lock skippy.lms_2005_20080603 query;
NOTE: SKIPPY.LMS_2005_20080603.DATA is not locked or in use by you or
any other users.


Thanks,
clh

Christopher L Hamilton
Washington Mutual | Deposit Risk Management

4. redirecting the output of LOCK LIST to output file insead of

5. redirecting the output of LOCK LIST to output file insead of Log

Hi,
I am writing a macro which will try to lock the dataset using LOCK DS_name
command. If due to contention the Lock fails then we need to trigger an
email which will contain details about the user/process holding the lock on
given table. By using LOCK DS_name LIST we can know this but these details
from LOCK LIST get written into Log file. Is there any way to redirect
output of this command to some dataset which we can use for sending an
email.

Regards,
Amol Deshmukh

6. SAS file locking

7. Proc sort causes a file lock

We are having a problem(in windows SAS Version 9.1 on a network server)
where during a proc sort the dataset that is being sorted to itself locks
and we can not get access to it. The problem is when SAS sorts a dataset
to itself it creates a tempory file with an  extension of .lck.  During
the sort it locks the orginal file so that no one can access it during the
sort. When the sort finishes correctly the orginal file is freed and
the .lck file is delete. However if the sort does not complete correctly
the orginal file remains locked ,administrator has to free it and the lck
file is saved. All the SAS processes after that fail so the job fails.
We've been working with SAS support and they claim something is touching
(like a anti-Virus) the file during the sort or we have a SAS server that
to weak or a bad disk drive. We tried everything nothing has worked.I was
hoping someone has run into this problem before and can help.

8. many delimited test files into one text file