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/arch_triplet/sane/libsane-net.a
              The static library implementing this backend.

       /usr/lib/arch_triplet/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)