Maximum number of characters in file name extension

[Guest]

Does Vista (& XP) set a limit on the maximum number of characters in a file
name extension? I know that XP will open files with 4 characters (for
example, .html). So, is there a maximum number of characters in a file name
extension? Does Vista (& XP) allow numeric characters or punctuation marks or
other typable characters? Does Vista (& XP) allow a combination of alphabetic
& numeric & alphanumeric characters in a file name extension?

Thank you.

 

[Andrew McLaren]

Does Vista (& XP) set a limit on the maximum number of characters in a
file
name extension? I know that XP will open files with 4 characters (for

These limits are defined by the NTFS file system. Windows XP, Server 2003
and Vista all use version 3.1 of the NTFS file system.

NTFS naming convensions are described here:

Naming a File
http://msdn2.microsoft.com/en-us/library/aa365247.aspx

The total length of the filename (basename plus extension) is 255 chars.
There is not specific limit on the extension length (eg you could have say,
200 char basename and 55 char extension, or even 1 char basename and 254
char extension).

All pathnames must generally fit within MAX_PATH, which is 260 chars
includng the final NUL char.

Some other handy references:

How NTFS Works
http://technet2.microsoft.com/windo...bf8e-4164-862d-dac5418c59481033.mspx?mfr=true

Making Room for Long Filenames
http://msdn2.microsoft.com/en-us/library/ms810456.aspx

Different conventions apply for FAT and FAT32 file systems, obviously. These
are pretty much in the legacy class, except for removable media like USB
drives. Vista SP1 will introduce support for the exFAT file system, for
flash drives and similar scenarios.

Hope it helps,