/dev/fd/0
through
/dev/fd/#
refer to file descriptors which can be accessed through the file
system.
If the file descriptor is open and the mode the file is being opened
with is a subset of the mode of the existing descriptor, the call:
fd = open("/dev/fd/0", mode);
and the call:
fd = fcntl(0, F_DUPFD, 0);
are equivalent.
Opening the files
/dev/stdin
,
/dev/stdout
and
/dev/stderr
is equivalent to the following calls:
fd = fcntl(STDIN_FILENO, F_DUPFD, 0);
fd = fcntl(STDOUT_FILENO, F_DUPFD, 0);
fd = fcntl(STDERR_FILENO, F_DUPFD, 0);
Flags to the
open(2)
call other than
O_RDONLY
,
O_WRONLY
and
O_RDWR
are ignored.
/dev/fd/#
/dev/stdin
/dev/stdout
/dev/stderr