2.11BSD/man/cat4/stdout.0
FD(4) UNIX Programmer's Manual FD(4)
NAME
fd, stdin, stdout, stderr file descriptor files
DESCRIPTION
The files /_d_e_v/_f_d/_0 through /_d_e_v/_f_d/# refer to file descrip-
tors 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 descrip-
tor, the call:
fd = open("/dev/fd/0", mode);
and the call:
fd = fcntl(0, F_DUPFD, 0);
are equivalent.
Opening the files /_d_e_v/_s_t_d_i_n, /_d_e_v/_s_t_d_o_u_t and /_d_e_v/_s_t_d_e_r_r 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.
FILES
/dev/fd/#
/dev/stdin
/dev/stdout
/dev/stderr
SEE ALSO
tty(4)
Printed 11/26/99 February 4, 1997 1