mount_fdesc(8) [netbsd man page]

MOUNT_FDESC(8)						    BSD System Manager's Manual 					    MOUNT_FDESC(8)

NAME

     mount_fdesc -- mount the file-descriptor file system

SYNOPSIS

     mount_fdesc [-o options] fdesc mount_point

DESCRIPTION

     The mount_fdesc command attaches an instance of the per-process file descriptor namespace to the global filesystem namespace.  The conven-
     tional mount point is /dev and the filesystem should be union mounted in order to augment, rather than replace, the existing entries in /dev.
     The directory specified by mount_point is converted to an absolute path before use.

     This command is normally executed by mount(8) at boot time.

     The options are as follows:

     -o      Options are specified with a -o flag followed by a comma separated string of options.  See the mount(8) man page for possible options
	     and their meanings.

     The contents of the mount point are fd, stderr, stdin, stdout and tty.

     fd is a directory whose contents appear as a list of numbered files which correspond to the open files of the process reading the directory.
     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.

     The files /dev/stdin, /dev/stdout and /dev/stderr appear as symlinks to the relevant entry in the /dev/fd sub-directory.  Opening them 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.

     The /dev/tty entry is an indirect reference to the current process's controlling terminal.  It appears as a named pipe (FIFO) but behaves in
     exactly the same way as the real controlling terminal device.

FILES

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

SEE ALSO

     mount(2), unmount(2), tty(4), fstab(5), mount(8)

HISTORY

     The mount_fdesc utility first appeared in 4.4BSD.

BUGS

     This filesystem may not be NFS-exported.

BSD
								  March 27, 1994							       BSD

Check Out this Related Man Page

DEVFS(5)						      BSD File Formats Manual							  DEVFS(5)

NAME

     devfs -- device file system

SYNOPSIS

     devfs   /dev    devfs rw 0 0

DESCRIPTION

     The device file system, or devfs, provides access to kernel's device namespace in the global file system namespace.  The conventional mount
     point is /dev.

     The file system includes several directories, links, symbolic links and devices, some of which can also be written.  In a chroot'ed environ-
     ment, devfs can be used to create a new /dev mount point.

     The mknod(8) tool can be used to recover deleted device entries under devfs.

     The fdescfs(5) filesystem is an alternate means for populating /dev/fd.  The character devices that both devfs and fdescfs(5) present in
     /dev/fd correspond to the open file descriptors of the process accessing the directory.  devfs only creates files for the standard file
     descriptors 0, 1 and 2.  fdescfs(5) creates files for all open descriptors.

     The options are as follows:

     -o options
	     Use the specified mount options, as described in mount(8).  The following devfs file system-specific options are available:

	     ruleset=ruleset
		     Set ruleset number ruleset as the current ruleset for the mount-point and apply all its rules.  If the ruleset number ruleset
		     does not exist, an empty ruleset with the number ruleset is created.  See devfs(8) for more information on working with devfs
		     rulesets.

FILES

     /dev	The normal devfs mount point.

EXAMPLES

     To mount a devfs volume located on /mychroot/dev:

	   mount -t devfs devfs /mychroot/dev

SEE ALSO

     fdescfs(5), devfs(8), mount(8)

HISTORY

     The devfs file system first appeared in FreeBSD 2.0.  It became the preferred method for accessing devices in FreeBSD 5.0 and the only method
     in FreeBSD 6.0.  The devfs manual page first appeared in FreeBSD 2.2.

AUTHORS

     The devfs manual page was written by Mike Pritchard <mpp@FreeBSD.org>.

BSD
								 February 9, 2012							       BSD

Linux and UNIX Man Pages

mount_fdesc(8) [netbsd man page]

Check Out this Related Man Page