获取 Windows 中的保留文件名

Question

It's known, you can't create a file with name con ( con.txt for example) in Windows. So, in my application user can input a custom file name (not via SaveFileDialog, just textbox to input name, not full path), and I want to show an error message, when user inputs invalid file name. Is there a way to get full list of reserved Windows file names ( con , prn , lpt and so on)?

Answer 1

Do not use the following reserved names for the name of a file:

CON, PRN, AUX, NUL, COM1, COM2, COM3, COM4, COM5, COM6, COM7, COM8, COM9, LPT1, LPT2, LPT3, LPT4, LPT5, LPT6, LPT7, LPT8, and LPT9.

Also avoid these names followed immediately by an extension; for example, NUL.txt is not recommended.

As per: https://msdn.microsoft.com/en-gb/library/windows/desktop/aa365247(v=vs.85).aspx

Answer 2

Take a look here: Reserved file names

Reserved filenames in Windows operating systems

aux con clock$ nul prn com1 com2 com3 com4 com5 com6 com7 com8 com9 lpt1 lpt2 lpt3 lpt4 lpt5 lpt6 lpt7 lpt8 lpt9

Answer 3

Just try to create that file in a %temp% folder. If you succeed, than, the name is valid. If you fail, you can show the user your message.

Also, I would check for already existing file with that name before creating.

After all, don't forget to delete it.

Answer 4

CON, PRN, AUX, NUL, COM1, COM2, COM3, COM4, COM5, COM6, COM7, COM8, COM9, LPT1, LPT2, LPT3, LPT4, LPT5, LPT6, LPT7, LPT8, and LPT9

Though you should use your code under try catch block and catch the exception system.IO.DirectoryNotFoundException

Answer 5

You can use GetFileType and disallow files of FILE_TYPE_CHAR in your application. That also works for reserved names like con.txt etc.

Answer 6

Pass the file name to GetFullPathName . If the result starts with \\\\.\\ , it is a device name. Java uses this method .

This method works only with NT-based Windows. If you still support Win9x, you will have to invoke a 16-bit DOS program to traverse the DOS device chain.