OSF

NAME

fd, stdin, stdout, stderr − File descriptors

DESCRIPTION

The /dev/fd/0 through /dev/fd/# files 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 /dev/stdin, /dev/stdout and /dev/stderr files 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() function other than O_RDONLY, O_WRONLY and O_RDWR are ignored. 

FILES

/dev/fd/#File descriptor files, where # (number sign) represents the file descriptor number. 

/dev/stdinSpecial file for the standard input device. 

/dev/stdout
Special file for the standard output device.

/dev/stderrSpecial file for the standard error device. 

RELATED INFORMATION

Files: tty(7)