Is a socket a file?

Socket. A socket is a special file used for inter-process communication, which enables communication between two processes. In addition to sending data, processes can send file descriptors across a Unix domain socket connection using the sendmsg() and recvmsg() system calls.

What type is a file descriptor?

A file descriptor is an unsigned integer used by a process to identify an open file. The number of file descriptors available to a process is limited by the /OPEN_MAX control in the sys/limits. h file. The number of file descriptors is also controlled by the ulimit -n flag.

Which are 3 standard files of descriptor?

Stdin, stdout, and stderr On a Unix-like operating system, the first three file descriptors, by default, are STDIN (standard input), STDOUT (standard output), and STDERR (standard error). The default data stream for input, for example in a command pipeline.

What does a socket descriptor do?

Each socket within the network has a unique name associated with it called a socket descriptor—a fullword integer that designates a socket and allows application programs to refer to it when needed.

What is socket descriptor in Unix?

In Unix and Unix-like computer operating systems, a file descriptor (FD, less frequently fildes) is a unique identifier (handle) for a file or other input/output resource, such as a pipe or network socket.

What file descriptor is Stdin?

File descriptor

What is bad file descriptor?

“Bad file descriptor” means that we tried to perform an operation on a file descriptor which is not active, probably closed beneath someone’s feet. There is no file path associated with it anymore.

Can a socket file descriptor be zero?

file descriptor 0 is always stdin.