7.6 fcntl Function

Performs the operation specified by command on the file descriptor filedes.

Attention: This interface function is implemented only by MPLAB XC32 C compilers.

Include

<fcntl.h>

Prototype

int fcntl(int filedes, int command, …)

Arguments

filedes: file descriptor on which the command is performed
command: command performed on file descriptor. Some commands require additional arguments to be supplied
...: the data associated with the command to be executed

Return Value

The return value and error conditions are dependent on the individual commands.

Remarks

This function is implemented as a stub that must be completed to suit the application.

The following table shows the available commands.


`F_DUPFD`	Duplicate the file descriptor (return another file descriptor pointing to the same open file).
`F_GETFD`	Get flags associated with the file descriptor.
`F_SETFD`	Set flags associated with the file descriptor.
`F_GETFL`	Get flags associated with the open file.
`F_SETFL`	Set flags associated with the open file.
`F_GETLK`	Test a file lock.
`F_SETLK`	Set or clear a file lock.
`F_SETLKW`	Like `F_SETLK`, but wait for completion.
`F_OFD_GETLK`	Test an open file description lock.
`F_OFD_SETLK`	Set or clear an open file description lock
`F_OFD_SETLKW`	Like `F_OFD_SETLK`, but block until lock is acquired.
`F_GETOWN`	Get process or process group ID to receive SIGIO signals.
`F_SETOWN`	Set process or process group ID to receive SIGIO signals.

Source File

fcntl.c