Safe stream update of file

Question

We perform updates of large text files by writing new records to a temp file, then replacing the old file with the temp file. A heavily abbreviated version:

Answer 1

This code snippet shows a technique for getting exclusive access to a file (read in this case):

// Try to open a file exclusively
FileInfo fi = new FileInfo(fullFilePath);

int attempts = maxAttempts;
do
{
    try
    {
        // Try to open for reading with exclusive access...
        fs = fi.Open(FileMode.Open, FileAccess.Read, FileShare.None);
    }
    // Ignore any errors... 
    catch { }

    if (fs != null)
    {
        break;
    }
    else
    {
        Thread.Sleep(100);
    }
}
while (--attempts > 0);

// Did we manage to open file exclusively?
if (fs != null)
{
    // use open file....

}