F.42 ctMBprefix

---

Stores a proper prefix to a Unicode filename string.

Short Name

ctMBprefix

TYPE

Utility

DECLARATION

NINT ctMBprefix(pTEXT dp, NINT FnType)

DESCRIPTION

c-tree Plus requires that the Unicode file name have a special 8-byte prefix that informs c-tree Plus about special file name encoding. ctMBprefix stores a proper prefix at dp of type FnType.

dp is a pTEXT because the name may be encoded as a byte stream or a wide character array and ctMBprefix does not assume that dp is aligned when used with UTF16.

FnType may be ctFnTypeUTF8 or ctFnTypeUTF16. Both of these constants are defined in ctport.h. ctFnPrefixSIZE holds the size of the prefix in bytes.

RETURN

Value	Symbolic Constant	Explanation
0	NO_ERROR	Prefix stored.
446	BMOD_ERR	FnType parameter is bad.

See Appendix A "c-tree Plus Error Codes" of the c-tree Plus Programmer's Reference Guide for a complete listing of valid c-tree Plus error values.

EXAMPLE

/* In the following example, getUnicodeUTF8string is assumed ** to be a routine which will fill-in a UTF8 encoded string up

** to a max length. GetUnicodeUTF16string performs in the same

** manner except that it works with 16 bit wide characters.

*/

COUNT datno8, datno16;

WCHAR utf16name[256];

TEXT utf8name[512];

ctMBprefix(utf8name,ctFnTypeUTF8);

getUnicodeUTF8string(utf8name + ctFnPrefixSIZE,512 -

ctFnPrefixSIZE);

datno8 = OPNRFIL(-1,utf8name,SHARED);

ctMBprefix((pTEXT) utf16name,ctFnTypeUTF16);

getUnicodeUTF16string(utf16name + ctFnPrefixSIZE / 2,

256 - ctFnPrefixSIZE / 2);

datno16 = OPNRFIL(-1,utf16name,SHARED);