[Overview][Constants][Types][Procedures and functions][Index] | Reference for unit 'Linux' (#rtl)

# epoll_ctl

Modify an epoll file descriptor

## Declaration

Source position: linux.pp line 286

`function epoll_ctl(`
`epfd: cint;`
`op: cint;`
`fd: cint;`
`event: PEpoll_Event`
`):cint;`

## Description

epoll_ctl performs the op operation on epoll file descriptor epfd. The operation will be monitored on file descriptor fd, and is optionally controlled by event.

op can be one of the following values:

EPOLL_CTL_ADD
  Add filedescriptor to list of events
EPOLL_CTL_MOD
  Modify event for filedescriptor
EPOLL_CTL_DEL
  Delete event for filedescriptor

The events field in event_data is a bitmask of one or more of the following values:

EPOLLIN
  The file is ready for read operations
EPOLLOUT
  The file is ready for write operations.
EPOLLPRI
  Urgent data is available for read operations.
EPOLLERR
  An error condition is signaled on the file descriptor.
EPOLLHUP
  A Hang up happened on the file descriptor.
EPOLLET
  Set the Edge Triggered behaviour for the file descriptor.
EPOLLONESHOT
  Set One-Shot behaviour for the file descriptor. The event will be triggered only once.

## Errors

On error -1 is returned, and errno is set accordingly.

## See also

epoll_create |  | Create new epoll file descriptor
epoll_wait |  | Wait for an event on an epoll file descriptor.
fpClose |  | Close file descriptor

Documentation generated on: May 14 2021