Rename Text File Used By Two applications

Question

Dears I have an application that write to a text file every time an event fires in the second application i want to rename this text file when it reach 2GB. The problem that if i run the rename command at the moment of the write moment this may run an exception or lead to loos a data that did not written on the file. If i Use Try and exception and the rename will occurs when there is no exception is there is any probability that i loss any data? Or Do You have any idea to prevent this? Kind Regards

Vulpes · Answer

You certainly won't be able to rename a file which another application is writing to because the file will be locked by the operating system. Attemping to do so will therefore generate an IOException - 'file being used by another process'. You can catch this exception and there should be no possibility that any writes which were simultaneously taking place will be lost. However the other application could have a problem if it attempts to write to the original file whilst it's in the process of being renamed. Unless it's been programmed to allow for this possibility then an error could result. In fact if it's writing frequently to such a large file then I wouldn't be surprised if the other application isn't keeping the file open with exclusive write access as long it's running. If that's the case then you won't be able to rename it in the meantime.