fd(4) File Formats fd(4)
NAME
fd - 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, and mode is ignored. As with dup, subsequent reads or writes on fd fail unless the origi-
nal 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.
SEE ALSO
creat(2), dup(2), open(2)
DIAGNOSTICS
open(2) returns -1 and EBADF if the associated file descriptor is not open.
SunOS 5.10 3 Jul 1990 fd(4)
