PIPE(2) Linux Programmer's Manual PIPE(2)
NAME
pipe, pipe2 - create pipe
SYNOPSIS
#include <unistd.h>
int pipe(int pipefd[2]);
#define _GNU_SOURCE
#include <unistd.h>
int pipe2(int pipefd[2], int flags);
DESCRIPTION
pipe() creates a pipe, a unidirectional data channel that can be used
for interprocess communication. The array pipefd is used to return two
file descriptors referring to the ends of the pipe. pipefd[0] refers
to the read end of the pipe. pipefd[1] refers to the write end of the
pipe. Data written to the write end of the pipe is buffered by the
kernel until it is read from the read end of the pipe. For further
details, see pipe(7).
If flags is 0, then pipe2() is the same as pipe(). The following val
ues can be bitwise ORed in flags to obtain different behavior:
O_NONBLOCK Set the O_NONBLOCK file status flag on the two new open
file descriptions. Using this flag saves extra calls to
fcntl(2) to achieve the same result.
O_CLOEXEC Set the close-on-exec (FD_CLOEXEC) flag on the two new file
descriptors. See the description of the same flag in
open(2) for reasons why this may be useful.
RETURN VALUE
On success, zero is returned. On error, -1 is returned, and errno is
set appropriately.
ERRORS
EFAULT pipefd is not valid.
EINVAL (pipe2()) Invalid value in flags.
