C# Constants:

const int _O_RDONLY = 0x0000;  /* open for reading only */
const int _O_WRONLY = 0x0001;  /* open for writing only */
const int _O_RDWR   = 0x0002;  /* open for reading and writing */
const int _O_APPEND = 0x0008;  /* writes done at eof */

const int _O_CREAT  = 0x0100;  /* create and open file */
const int _O_TRUNC  = 0x0200;  /* open and truncate */
const int _O_EXCL   = 0x0400;  /* open only if file doesn't already exist */

/* O_TEXT files have <cr><lf> sequences translated to <lf> on read()'s,
** and <lf> sequences translated to <cr><lf> on write()'s
*/
const int _O_TEXT    = 0x4000;  /* file mode is text (translated) */
const int _O_BINARY  = 0x8000;  /* file mode is binary (untranslated) */
const int _O_WTEXT   = 0x10000; /* file mode is UTF16 (translated) */
const int _O_U16TEXT = 0x20000; /* file mode is UTF16 no BOM (translated) */
const int _O_U8TEXT  = 0x40000; /* file mode is UTF8  no BOM (translated) */

const int _O_NOINHERIT   = 0x0080;  /* child process doesn't inherit file */
const int _O_TEMPORARY   = 0x0040;  /* Temporary file bit - file is deleted when last handle is closed */
const int _O_SHORT_LIVED = 0x1000;  /* temporary storage file, try not to flush */

const int _O_SEQUENTIAL  = 0x0020;  /* file access is primarily sequential */
const int _O_RANDOM      = 0x0010;  /* file access is primarily random */

/* Non-ANSI names for compatibility */
const int O_RDONLY      =  _O_RDONLY;
const int O_WRONLY      =  _O_WRONLY;
const int O_RDWR    =  _O_RDWR;
const int O_APPEND      =  _O_APPEND;
const int O_CREAT       =  _O_CREAT;
const int O_TRUNC       =  _O_TRUNC;
const int O_EXCL    =  _O_EXCL;
const int O_TEXT    =  _O_TEXT;
const int O_BINARY      =  _O_BINARY;
const int O_RAW     =  _O_BINARY;
const int O_TEMPORARY   =  _O_TEMPORARY;
const int O_NOINHERIT   =  _O_NOINHERIT;
const int O_SEQUENTIAL  =  _O_SEQUENTIAL;
const int O_RANDOM      =  _O_RANDOM;

VB Constants:

TODO

Notes:

None.