CompuServe Messages

Actually, there is an issue associated with the Join command dealing with both input and output that is actually non-solvable. The constraints on the issue are that 1) You can't open a file more than once – one example is CON: windows which would pop up each time you did this (this was a bug reported and fixed in the copy command). 2) Because of soft/hard links, you can't tell if the file is the same without opening it. 3) Because of some pathological cases, it was not possible to open up all the input files first. 4) You can't even compare strings because of wild cards in the input. 5) You can't solve the problem with locks because not all file handlers support locks. We went through a number of solutions to the problem but were never able to resolve all the constraints. Attempts to delay opening the output file until later also invoked some bugs (but I don't remember them offhand).