- NetBSD Manual Pages
FD(4) NetBSD Kernel Interfaces Manual FD(4)
Powered by man-cgi (2021-06-01).
Maintained for NetBSD
by Kimmo Suominen.
Based on man-cgi by Panagiotis Christias.
fd, stdin, stdout, stderr -- file descriptor files
The files /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);
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
NetBSD 4.0 June 9, 1993 NetBSD 4.0