Login | Register   
LinkedIn
Google+
Twitter
RSS Feed
Download our iPhone app
TODAY'S HEADLINES  |   ARTICLE ARCHIVE  |   FORUMS  |   TIP BANK
Browse DevX
Sign up for e-mail newsletters from DevX


Tip of the Day
Language: Visual Basic
Expertise: Beginner
Oct 1, 1996

Reliable File Writing

Question:
I have a DOS-based application (QB4.5) which has been running for some years and I have now updated it to Visual Basic.

The application handles several async serial ports writing data to random access file shared between all ports.

Due to the async nature of the program and the need to keep the ports serviced, the DOS version used int 21H function 68H (Commit File) every few seconds to flush the file buffers to disk. This avoids closing the files and any possibility of serious data loss should there be power failure.

I can find no way of achieving the same thing in VB. Do you know of any API function or DLL which gives access to the required DOS interrupts,

Answer:
Whenever you need to do a write, you open the file, append the data to it, and then close the file? This method is commonly used for writing messages to error logs. If you do not close the file, you cannot be guaranteed that the data is there. Also, if the program crashes, and you do not close the file you will lose your information also.

DevX Pro
 
Comment and Contribute

 

 

 

 

 


(Maximum characters: 1200). You have 1200 characters left.

 

 

Sitemap
Thanks for your registration, follow us on our social networks to keep up-to-date