select() is a system call that allows you to monitor multiple file descriptors, typically used for managing I/O operations on sockets. It works by creating sets of file descriptors you want to monitor using the fd_set data structure.
You set up three fd_set structures: one for the file descriptors you want to read from, one for those you want to write to, and one for exceptions. These sets are manipulated using functions like FD_SET(), FD_CLR(), and FD_ZERO() to add, remove, or clear file descriptors.
You pass these sets, along with a timeout value, to the select() function. select() will block until one or more file descriptors in the sets become ready, or until the timeout expires. Once select() returns, you can check which file descriptors are ready and perform the corresponding I/O operations without blocking the entire program.
select() is a system call that allows you to monitor multiple file descriptors, typically used for managing I/O operations on sockets. It works by creating sets of file descriptors you want to monitor using the fd_set data structure.
You set up three fd_set structures: one for the file descriptors you want to read from, one for those you want to write to, and one for exceptions. These sets are manipulated using functions like FD_SET(), FD_CLR(), and FD_ZERO() to add, remove, or clear file descriptors.
You pass these sets, along with a timeout value, to the select() function. select() will block until one or more file descriptors in the sets become ready, or until the timeout expires. Once select() returns, you can check which file descriptors are ready and perform the corresponding I/O operations without blocking the entire program.