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(8) server. This will
              prevent the backend from blocking for several  minutes  trying  to  connect  to  an
              unresponsive  saned(8)  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 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/x86_64-linux-gnu/sane/libsane-net.a
              The static library implementing this backend.

       /usr/lib/x86_64-linux-gnu/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.   On  *NIX  systems,  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(8) 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(8) 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)