NAME

fd, stdin, stdout, stderr file descriptor files

DESCRIPTION

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);

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. 

FILES

/dev/fd/#
/dev/stdin
/dev/stdout
/dev/stderr

SEE ALSO

tty(4)

4th Berkeley Distribution  —  February 4, 1997