Allow testing for existence of specific file types in wxFileName.

Add "flags" parameter to wxFileName::Exists() to allow testing for the
existing of files of specific type: not only regular or directory but also
symlink, device, FIFO or socket.

And also to pass wxFILE_EXISTS_NO_FOLLOW flag inhibiting following the
symlinks without using DontFollowLink().

Closes #14542.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@72707 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/filename.h

@@ -108,6 +108,20 @@ enum
     wxPATH_RMDIR_RECURSIVE  = 0x0002   // delete all recursively (dangerous!)
 };
 
+// FileExists flags
+enum
+{
+    wxFILE_EXISTS_REGULAR   = 0x0001,  // check for existence of a regular file
+    wxFILE_EXISTS_DIR       = 0x0002,  // check for existence of a directory
+    wxFILE_EXISTS_SYMLINK   = 0x0004,  // check for existence of a symbolic link
+    wxFILE_EXISTS_DEVICE    = 0x0008,  // check for existence of a device
+    wxFILE_EXISTS_FIFO      = 0x0016,  // check for existence of a FIFO
+    wxFILE_EXISTS_SOCKET    = 0x0032,  // check for existence of a socket
+                                       // gap for future types
+    wxFILE_EXISTS_ANY       = 0x0FFF,  // check for existence of anything
+    wxFILE_EXISTS_NO_FOLLOW = 0x1000   // don't dereference a contained symlink
+};
+
 #if wxUSE_LONGLONG
 // error code of wxFileName::GetSize()
 extern WXDLLIMPEXP_DATA_BASE(const wxULongLong) wxInvalidSize;
@@ -224,8 +238,8 @@ public:
 
         // does anything at all with this name (i.e. file, directory or some
         // other file system object such as a device, socket, ...) exist?
-    bool Exists() const;
-    static bool Exists(const wxString& path);
+    bool Exists(int flags = wxFILE_EXISTS_ANY) const;
+    static bool Exists(const wxString& path, int flags = wxFILE_EXISTS_ANY);
 
 
         // checks on most common flags for files/directories;