How can I do an atomic write/append in C#, or how do I get files opened with the FILE_APPEND_DATA flag?

Question

Under most Unixes and Posix conforming operating systems performing an open() operating system call with the O_APPEND indicates to the OS that writes are to be atomic append

Answer 1

Why can't you use

System.IO.File.AppendAllText("C:\\somefile.txt", "some content");

? That's a thread-safe/"atomic" call as well.