FD_ZERO - Linux

Overview

FD_ZERO initializes a file descriptor set to empty. It is commonly used for initializing file descriptor sets before adding file descriptors to them.

Syntax

void FD_ZERO(fd_set *set);

Options/Flags

None

Examples

// Initialize a file descriptor set
fd_set fds;
FD_ZERO(&fds);

// Add a file descriptor to the set
FD_SET(fd, &fds);

// Check if a file descriptor is in the set
if (FD_ISSET(fd, &fds)) {
  // Handle the file descriptor
}

Common Issues

• Forgetting to initialize a file descriptor set before using it.

Integration

FD_ZERO is often used in conjunction with other file descriptor set functions, such as FD_SET and FD_ISSET, to manage file descriptors in server applications or for multiplexing I/O.

Related Commands

• select – Selects file descriptors for reading, writing, or error conditions
• poll – Polls file descriptors for events
• epoll – Efficient polling mechanism for large numbers of file descriptors