FindFirstFile undocumented wildcard or bug?

Question

MSDN says:

HANDLE WINAPI FindFirstFile( LPCTSTR lpFileName, LPWIN32_FIND_DATA lpFindFileData );

lpFileName The directory or pa

Answer 1

According to a post on the OSR ntfsd list from 2002, this is an intentional feature of NtQueryDirectoryFile/ZwQueryDirectoryFile via FsRtlIsNameInExpression. < and > correspond to * and ?, but perform matching "using MS-DOS semantics".

The FsRtlIsNameInExpression states:

The following wildcard characters can be used in the pattern string.

Wildcard character  Meaning

* (asterisk)        Matches zero or more characters.

? (question mark)   Matches a single character.

DOS_DOT             Matches either a period or zero characters beyond the name
                    string.

DOS_QM              Matches any single character or, upon encountering a period
                    or end of name string, advances the expression to the end of
                    the set of contiguous DOS_QMs.

DOS_STAR            Matches zero or more characters until encountering and
                    matching the final . in the name.

For some reason, this page does not give the values of the DOS_* macros, but ntifs.h does:

//  The following constants provide addition meta characters to fully
//  support the more obscure aspects of DOS wild card processing.

#define DOS_STAR        (L'<')
#define DOS_QM          (L'>')
#define DOS_DOT         (L'"')