473,378 Members | 1,393 Online
Bytes | Software Development & Data Engineering Community
Post Job

Home Posts Topics Members FAQ

Join Bytes to post your question to a community of 473,378 software developers and data experts.

Invalid argument with fcntl.fcntl

I am trying to use the advisory locking with fcntl over NFS (thus, me
choosing fcntl instead of flock and friends).

I have the following code:
lockdata = struct.pack ("hhllhh", fcntl.F_RDLCK, 0, 0, 0, 0, 0)
print self.fd, type (self.fd), len (lockdata), type (lockdata)
ret = fcntl.fcntl (self.fd, fcntl.F_GETLK, lockdata)

when this code executes, I always get the following:

<open file 'test.py', mode 'a' at 0xb7e99458<type 'file'16 <type
'str'Traceback (most recent call last):
File "<stdin>", line 1, in ?
File "filelock.py", line 154, in _get_lock_state_nfs
ret = fcntl.fcntl (self.fd, fcntl.F_GETLK, lockdata)
IOError: [Errno 22] Invalid argument
If I execute the same code in the Python interpreter (replacing self.fd
with an open file object), it work.

Can anyone shed some light on why this code would produce that error?
Thanks

--
Mitko Haralanov mi***@qlogic.com
Senior Software Engineer 650.934.8064
System Interconnect Group http://www.qlogic.com

==========================================
FORTRAN is a good example of a language which is easier to parse
using ad hoc techniques.
-- D. Gries
[What's good about it? Ed.]
Jun 6 '07 #1
0 1780

This thread has been closed and replies have been disabled. Please start a new discussion.

Similar topics

6
by: Pierre Rouleau | last post by:
Hi all! I am using Python 2.3.1 on Win32 (NT, 2000). Whenever a file imports the standard tempfile module, Python 2.3.1 issues the following warning: C:\Python23\lib\fcntl.py:7:...
0
by: Ryan Grow | last post by:
Hi, I'm trying to use fcntl to set an existing file descriptor to be nonblocking. This contrived example exhibits the behavior of python that is preventing me from doing this: import os,...
4
by: Omid Fatemi | last post by:
I followed discussion in the group about this problem: ImportError: No module named fcntl I found out there are two modules: FCNTL fcntl the first one is obsolete and shouldn't be used. But...
0
by: Richard | last post by:
I am writing a script which accesses a DBM file using SDBM. The program works but throws out a warning of: - Argument "O_RDWR" isn't numeric in null operation I've included Fcntl but that...
1
by: CloudSolutions | last post by:
Introduction: For many beginners and individual users, requiring a credit card and email registration may pose a barrier when starting to use cloud servers. However, some cloud server providers now...
0
by: Faith0G | last post by:
I am starting a new it consulting business and it's been a while since I setup a new website. Is wordpress still the best web based software for hosting a 5 page website? The webpages will be...
0
isladogs
by: isladogs | last post by:
The next Access Europe User Group meeting will be on Wednesday 3 Apr 2024 starting at 18:00 UK time (6PM UTC+1) and finishing by 19:30 (7.30PM). In this session, we are pleased to welcome former...
0
by: ryjfgjl | last post by:
In our work, we often need to import Excel data into databases (such as MySQL, SQL Server, Oracle) for data analysis and processing. Usually, we use database tools like Navicat or the Excel import...
0
by: Charles Arthur | last post by:
How do i turn on java script on a villaon, callus and itel keypad mobile phone
0
by: aa123db | last post by:
Variable and constants Use var or let for variables and const fror constants. Var foo ='bar'; Let foo ='bar';const baz ='bar'; Functions function $name$ ($parameters$) { } ...
0
by: ryjfgjl | last post by:
If we have dozens or hundreds of excel to import into the database, if we use the excel import function provided by database editors such as navicat, it will be extremely tedious and time-consuming...
0
BarryA
by: BarryA | last post by:
What are the essential steps and strategies outlined in the Data Structures and Algorithms (DSA) roadmap for aspiring data scientists? How can individuals effectively utilize this roadmap to progress...
1
by: Sonnysonu | last post by:
This is the data of csv file 1 2 3 1 2 3 1 2 3 1 2 3 2 3 2 3 3 the lengths should be different i have to store the data by column-wise with in the specific length. suppose the i have to...

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.