NAME
sane-net - SANE network backend
DESCRIPTION
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 net.conf file contains both backend options and a list of host
names (or IP addresses) that should be contacted for scan requests.
Anything that isn’t one of the options listed below will be treated as
an host name.
connect_timeout = nsecs
Timeout (in seconds) for the initial connection to the saned
server. This will prevent the backend from blocking for several
minutes trying to connect to an unresponsive saned host (network
outage, host down, ...). The environment variable
SANE_NET_TIMEOUT can also be used to specify the timeout at
runtime.
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:
new.scanner.com:[::1]:192.168.0.2:scanner.univ.edu
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_NET_TIMEOUT
Number of seconds to wait for a response from the saned server
for the initial connection request.
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.
SEE ALSO
sane(7), saned(8), sane-dll(5), scanimage(1)
http://www.penguin-breeder.org/?page=sane-net
AUTHOR
David Mosberger and Andreas Beck
14 Jul 2008 sane-net(5)