FD(4FS) 4FS FD(4FS)

NAME


fd, stdin, stdout, stderr - file descriptor files

DESCRIPTION


These files, conventionally called /dev/fd/0, /dev/fd/1, /dev/fd/2, and so
on, refer to files accessible through file descriptors. If file descriptor
n is open, these two system calls have the same effect:

fd = open("/dev/fd/<n>", mode);
fd = dup(n);

On these files creat(2) is equivalent to open(2), and mode is ignored. As
with dup(2), subsequent reads or writes on fd fail unless the original file
descriptor allows the operations.

For convenience in referring to standard input, standard output, and
standard error, an additional set of names is provided: /dev/stdin is a
synonym for /dev/fd/0, /dev/stdout for /dev/fd/1, and /dev/stderr for
/dev/fd/2.

DIAGNOSTICS


open(2) returns -1 and errno is set to EBADF if the associated file
descriptor is not open.

SEE ALSO


creat(2), dup(2), open(2)

OmniOS July 3, 1990 OmniOS