fcntl(5)
NAME
fcntl − file control options
SYNTAX
#include <fcntl.h>
DESCRIPTION
The fcntl system call provides for control over open files. This include file describes requests and arguments to the fcntl and open.
/∗ Flag values accessible to open(2) and fcntl(2) ∗/
/∗ (The first three can only be set by open) ∗/
#define O_RDONLY 0
#define O_WRONLY 1
#define O_RDWR 2
#define O_NDELAY 04 /∗ Non-blocking I/O ∗/
#define O_APPEND 010 /∗ append (writes guaranteed at end) ∗/
/∗ Flag values accessible only to open(2) ∗/
#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 ∗/
/∗ fcntl(2) requests ∗/
#define F_DUPFD 0 /∗ Duplicate fildes ∗/
#define F_GETFD 1 /∗ Get fildes flags ∗/
#define F_SETFD 2 /∗ Set fildes flags ∗/
#define F_GETFL 3 /∗ Get file flags ∗/
#define F_SETFL 4 /∗ Set file flags ∗/