Your try/catch is the way to do things. If the call to File.Open
succeeds, then you can write to to the file. The idea is to keep the file open. I would suggest something like:
bool openSuccessful = false;
while (!openSuccessful)
{
try
{
using (var writer = new StreamWriter(masterlog, true)) // append
{
// successfully opened file
openSuccessful = true;
try
{
foreach (var line in File.ReadLines(individualLogFile))
{
writer.WriteLine(line);
}
}
catch (exceptions that occur while writing)
{
// something unexpected happened.
// handle the error and exit the loop.
break;
}
}
}
catch (exceptions that occur when trying to open the file)
{
// couldn't open the file.
// If the exception is because it's opened in another process,
// then delay and retry.
// Otherwise exit.
Sleep(1000);
}
}
if (!openSuccessful)
{
// notify of error
}
So if you fail to open the file, you sleep and try again.
See my blog post, File.Exists is only a snapshot, for a little more detail.