473,406 Members | 2,847 Online
Bytes | Software Development & Data Engineering Community
Post Job

Home Posts Topics Members FAQ

Join Bytes to post your question to a community of 473,406 software developers and data experts.

Preventing simultaneous access to a file by C++ CGI instances

A CGI script in C++ running on Apache RH appends the contents of an HTML
form to an existing text file. Several clients may fill out the form and
call the CGI script at the same time and thus more than one CGI instance
might try to open and append text to the file at the same time.
How can I lock the file so that only one single CGI instance will be
able to open and write to the file?
Thanks!
Pierre

Jul 22 '05 #1
1 1591
Pierre Alexis wrote:
A CGI script in C++ running on Apache RH appends the contents of an HTML
form to an existing text file. Several clients may fill out the form and
call the CGI script at the same time and thus more than one CGI instance
might try to open and append text to the file at the same time.
How can I lock the file so that only one single CGI instance will be
able to open and write to the file?
Thanks!


You could write a mutex in C++ based on the pres/absence of additional
files, but your system probably provides a better alternative. If
you're on unix, read the man page for flock.

Jul 22 '05 #2

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

Similar topics

19
by: Claudio Grondi | last post by:
I would like to save time copying the same file (>6 GByte) to various different target storage media connected to the system via USB. Is there a (Python or other) tool able to help me to do...
5
by: Fred | last post by:
Hi out there, I have problems finding a way to warn a user that another user intends soon to update the same specific row. Let me explain. User 1 get to a JSP "update customer record" page....
1
by: slugger | last post by:
Hope this is not OT: I am running into some strange things whenever my ASP pages send out simultaneous requests to another ASP page which in turn gains access to a MySQL database using a DSNless...
1
by: Semaj | last post by:
Environment: DB2 8.1.4; Windows 2000 We are evaluating the feasibility of upgrading our production DB from 7.2 to 8.1. During this process we've encountered an error when starting our...
3
by: Boni | last post by:
Dear all, I create a big number of a class instances of some class. Sometimes this instances must be collected (all pointers are deleted, but instance is not explicitly disposed).But sometimes I...
12
by: Dan V. | last post by:
Since an ASP.NET/ADO.NET website is run on the server by a single "asp_net worker process", therefore doesn't that mean that even 50 simultaneous human users of the website would appear to the...
10
by: David Hirschfield | last post by:
Here's a strange concept that I don't really know how to implement, but I suspect can be implemented via descriptors or metaclasses somehow: I want a class that, when instantiated, only defines...
9
by: David | last post by:
With a non-server app there is one instance of the program running and one user 'using' it at a time. With this scenario I'm pretty comfortable with variable scope and lifetime. With a server app...
0
by: Charles | last post by:
well, I am following up in this newsgroup only since it seems to offset people in the other one. MyApplication_StartupNextInstance seems to be the solution for running several instances of the...
0
by: Charles Arthur | last post by:
How do i turn on java script on a villaon, callus and itel keypad mobile phone
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...
0
marktang
by: marktang | last post by:
ONU (Optical Network Unit) is one of the key components for providing high-speed Internet services. Its primary function is to act as an endpoint device located at the user's premises. However,...
0
jinu1996
by: jinu1996 | last post by:
In today's digital age, having a compelling online presence is paramount for businesses aiming to thrive in a competitive landscape. At the heart of this digital strategy lies an intricately woven...
0
by: Hystou | last post by:
Overview: Windows 11 and 10 have less user interface control over operating system update behaviour than previous versions of Windows. In Windows 11 and 10, there is no way to turn off the Windows...
0
tracyyun
by: tracyyun | last post by:
Dear forum friends, With the development of smart home technology, a variety of wireless communication protocols have appeared on the market, such as Zigbee, Z-Wave, Wi-Fi, Bluetooth, etc. Each...
0
agi2029
by: agi2029 | last post by:
Let's talk about the concept of autonomous AI software engineers and no-code agents. These AIs are designed to manage the entire lifecycle of a software development project—planning, coding, testing,...
0
isladogs
by: isladogs | last post by:
The next Access Europe User Group meeting will be on Wednesday 1 May 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 a new...

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.