The
sane-net
library implements a SANE (Scanner Access Now Easy) backend that
provides access to image acquisition devices through a network
connection. This makes it possible to control devices attached to a
remote host and also provides a means to grant users access to
protected resources.
DEVICE NAMES
This backend expects device names of the form:
host:device
Where
host
is the name (or IP address) of the (remote-) host and
device
is the name of the device on this host that should be addressed.
If the device name does not contain a colon (:), then the entire string
is treated as the
device
string for the default host. The default host is the host listed last
in the configuration file (see below).
An IPv6 address can be specified enclosed in square brackets:
[::1]:device
CONFIGURATION
The contents of the
net.conf
file is a list of host names (or IP addresses) that should be contacted for
scan requests. Empty lines and lines starting with a hash mark (#) are
ignored. Note that IPv6 addresses in this file do not need to be enclosed
in square brackets. A sample configuration file is shown below:
scan-server.somedomain.firm
192.168.0.1
# this is a comment
localhost
::1
The above list of hosts can be extended at run-time using environment
variable
SANE_NET_HOSTS.
This environment variable is a colon-separated list of hostnames or IP
addresses that should be contacted in addition to the hosts mentioned in
the configuration file. For example, a user could set the environment
variable to the string:
To request that hosts
new.scanner.com
,
[::1]
,
192.168.0.2
and
scanner.univ.edu
are contacted in addition to the hosts listed above.
For this backend to function properly, it is also necessary to define the
sane-port
service in
/etc/services.
The
sane
service should be defined using a line of the following form:
sane-port 6566/tcp # SANE network scanner daemon
FILES
/etc/sane.d/net.conf
The backend configuration file (see also description of
SANE_CONFIG_DIR
below).
/usr/lib/sane/libsane-net.a
The static library implementing this backend.
/usr/lib/sane/libsane-net.so
The shared library implementing this backend (present on systems that
support dynamic loading).
ENVIRONMENT
SANE_CONFIG_DIR
This environment variable specifies the list of directories that may
contain the configuration file. Under UNIX, the directories are
separated by a colon (`:'), under OS/2, they are separated by a
semi-colon (`;'). If this variable is not set, the configuration file
is searched in two default directories: first, the current working
directory (".") and then in /etc/sane.d. If the value of the
environment variable ends with the directory separator character, then
the default directories are searched after the explicitly specified
directories. For example, setting
SANE_CONFIG_DIR
to "/tmp/config:" would result in directories "tmp/config", ".", and
"/etc/sane.d" being searched (in this order).
SANE_NET_HOSTS
A colon-separated list of host names or IP addresses to be contacted by this
backend.
SANE_DEBUG_NET
If the library was compiled with debug support enabled, this
environment variable controls the debug level for this backend. E.g.,
a value of 128 requests all debug output to be printed. Smaller
levels reduce verbosity.
BUGS
If saned has timed out, the net backend may loop with authorization requests.
