is a daemon which implements a filesystem containing a symbolic link to
subdirectory within a user's home directory, depending on the user
which accessed that link. It was primarily designed to redirect
incoming mail to users' home directories, so that it can read from
operates by mounting itself as an
server for the directory containing
which defaults to
Lookups within that directory are handled by
which uses the password map to determine how to resolve the lookup.
The directory will be created if it doesn't already exist. The symbolic link will be to the accessing user's home directory, with
appended to it. If not specified,
This directory will also be created if it does not already exist.
A SIGTERM sent to
will cause it to shutdown. A SIGHUP will flush the internal
caches, and reload the password map. It will also close and
reopen the log file, to enable the original log file to be
removed or rotated. A SIGUSR1 will cause it to dump its internal
table of user IDs and home directories to the file
Alternate directory. The name of the directory to which
the symbolic link returned by
will point, if it cannot access the home directory of the user. This
This directory will be created if it doesn't exist. It is expected
that either users will read these files, or the system administrators
will run a script to resend this "lost mail" to its owner.
will cache the validity of home directories for this interval, in
seconds. Entries which have been verified within the last
seconds will not be verified again, since the operation could
be expensive, and the entries are most likely still valid.
After the interval has expired,
will re-verify the validity of the user's home directory, and
reset the cache time-counter. The default value for
is 300 seconds (5 minutes).
Force fast startup. This option tells
to skip startup-time consistency checks such as existence of mount
directory, alternate spool directory, symlink to be hidden under the
mount directory, their permissions and validity.
Set the special group HLFS_GID to
Programs such as
which access the mailboxes of other users) must be setgid HLFS_GID to
work properly. The default group is "hlfs". If no group is provided,
and there is no group "hlfs", this feature is disabled.
Help. Print a brief help message, and exit.
Map-reloading interval. Each
will reload the password map.
needs the password map for the UIDs and home directory pathnames.
schedules a SIGALRM to reload the password maps. A SIGHUP sent to
will force it to reload the maps immediately. The default
is 900 seconds (15 minutes.)
Specify a log file to which
will record events. If
is the string
then the log messages will be sent to the system log daemon by
using the LOG_DAEMON facility.
This is also the default.
will not verify the validity of the symbolic link it will be
returning, or that the user's home directory contains
sufficient disk-space for spooling. This can speed up
at the cost of possibly returning symbolic links to home
directories which are not currently accessible or are full.
validates the symbolic-link in the background.
option overrides the meaning of the
option, since no caching is necessary.
Mount options. Mount options which
will use to mount itself on top of
is set to "ro". If the system supports symbolic-link caching, default
options are set to "ro,nocache".
Outputs the process-id of
to standard output where it can be saved into a file.
Version. Displays version information to standard error.
Specify run-time logging options. The options are a comma separated
list chosen from: fatal, error, user, warn, info, map, stats, all.
to run on systems that cannot turn off the NFS attribute-cache. Use of
this option on those systems is discouraged, as it may result in loss
or mis-delivery of mail. The option is ignored on systems that can turn
off the attribute-cache.
Select from a variety of debugging options. Prefixing an
option with the string
reverses the effect of that option. Options are cumulative.
The most useful option is
Since this option is only used for debugging other options are not
documented here. A fuller description is available in the program
source. A SIGUSR1 sent to
will cause it to dump its internal password map to the file
Read the user-name, user-id, and home directory information from the file
to read the password database. This option allows you to override the
default database, and is useful if you want to map users' mail files to a
directory other than their home directory. Only the username, uid, and
home-directory fields of the file
are read and checked. All other fields are ignored. The file
must otherwise be compliant with Unix System 7 colon-delimited format
directory under which
mounts itself and manages the symbolic link
default sub-directory in the user's home directory, to which the
symbolic link returned by
directory to which
symbolic link returned by
points if it is unable to verify the that
user's home directory is accessible.
Erez Zadok <email@example.com>, Computer Science Department, Stony Brook
University, Stony Brook, New York, USA.
Alexander Dupuy <firstname.lastname@example.org>, System Management ARTS,
White Plains, New York, USA.
Other authors and contributors to am-utils are listed in the
file distributed with am-utils.