Shareable writing into file

[AlexanderM]

Hello.

I need to write in a log file from several processes.

I am using the next solution:

int logFile;
logFile = open(stampedPath.ptr, O_WRONLY | O_APPEND | O_CREAT, 0666);
write(logFile, buffer.ptr, buffer.len);//to achieve atomic output
close(logFile);

 In Linux(Red Hat) it works perfectly.

On OpenVMS I've got the next message in the second process: file currently locked by another user.

I've read about fwrite with additional keys from c language extension, but it is queit hard to find out in google full manual for this keys.

Furthermore:

• I am not shure that in this case family of printf functions  will give atomic output (in Linux they allow for a processes to mix output).
• I dont want to duplicate the code.

Could I resolve this situation with open/write/close using?

[AlexanderM]

I've got some hurry with it. I've found the post with linked issue.

If the problem and the solution is identical I'll delete this one.

[AlexanderM · Accepted solution]

solution

 logFile = open(stampedPath.ptr, O_WRONLY | O_APPEND | O_CREAT, 0666
#ifdef VAX
                 ,"shr = del, get, put, upd", "ctx = stm", "ctx = bin"
#endif