open() system call (Cont’d)

open() system call (Cont’d)

􀁺 The allowable option_flags as defined in
"/usr/include/fcntl.h" are:
#define O_RDONLY 0 /* Open the file for reading only */
#define O_WRONLY 1 /* Open the file for writing only */
#define O_RDWR 2 /* Open the file for both reading and writing*/
#define O_NDELAY 04 /* Non-blocking I/O */
#define O_APPEND 010 /* append (writes guaranteed at the end) */
#define O_CREAT 00400 /*open with file create (uses third open arg) */
#define O_TRUNC 01000 /* open with truncation */
#define O_EXCL 02000 /* exclusive open */
􀁺 Multiple values are combined using the | operator (i.e.
bitwise OR).