Provided by: libsane_1.0.17-1ubuntu4_i386 bug

NAME

       sane-dll - SANE dynamic backend loader

DESCRIPTION

       The  sane-dll  library  implements  a  SANE  (Scanner  Access Now Easy)
       backend that provides access to  an  arbitrary  number  of  other  SANE
       backends.   These  backends  may  either  be pre-loaded at the time the
       sane-dll library is built or, on systems that support  dynamic  loading
       of  shared  libraries,  the  backends may be loaded at runtime.  In the
       latter  case,  adding  support  for  a  new  backend  simply   involves
       installing the relevant library in /usr/lib/sane and adding an entry to
       the dll.conf configuration file.  In other words, no applications  need
       to be modified or recompiled to add support for new devices.

DEVICE NAMES

       This backend expects device names of the form:

              backend:device

       Where  backend is the name of the backend and device is the name of the
       device in this backend 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 backend.   The  default  backend  is  the
       backend  listed last in the configuration file (see below) or the first
       pre-loaded backend (if any).

CONFIGURATION

       The contents of the dll.conf file is a list of backend names  that  may
       be  loaded  dynamically  upon  demand.   Empty  lines are ignored, also
       everything after a hash mark (#). A sample configuration file is  shown
       below:

              net
              # this is a comment
              pnm
              mustek

       Note  that  backends that were pre-loaded when building this library do
       not have to be listed in  this  configuration  file.   That  is,  if  a
       backend  was  preloaded,  then  that  backend  will  always be present,
       regardless of whether it’s listed in the configuration file or not.

       The   list   of   preloaded   backends   is   determined    by    macro
       PRELOADABLE_BACKENDS  in  file  backend/Makefile.in  of the SANE source
       code distribution.  After changing the  value  of  this  macro,  it  is
       necessary to reconfigure, rebuild, and reinstall SANE for the change to
       take effect.

       Aliases are defined in the config file  dll.aliases.   It  can  contain
       entries of the form

              alias SomeName SaneDeviceName
              alias "Some Name" SaneDeviceName
              hide SaneDeviceName

       For example:

              alias Epson net:somehost:epson:/dev/sgX
              alias "Siemens ST400" st400:/dev/sgY
              hide net:somehost:pnm:0
              hide net:somehost:pnm:1
              alias "Read from file" pnm:0
              hide pnm:1

       Aliased device names are automatically hidden.

       The idea is that users don’t have to deal with complicated device names
       (especially for networked devices), and to hide other exported  devices
       which  might  confuse  them.  Note  that  a  hidden device can still be
       accessed if the device name is known, it just  doesn’t  appear  on  the
       list.

FILES

       /etc/sane.d/dll.aliases
              The list of aliased or hidden backends.

       /etc/sane.d/dll.conf
              The   backend   configuration  file  (see  also  description  of
              SANE_CONFIG_DIR below).

       /usr/lib/sane/libsane-dll.a
              The static library implementing this backend.

       /usr/lib/sane/libsane-dll.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_DEBUG_DLL
              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.

              Value  Description
              0      print severe errors only
              1      print normal errors and important messages
              2      print normal messages
              3      print debugging messages
              4      print everything

              Example: export SANE_DEBUG_DLL=3

SEE ALSO

       sane(7), scanimage(1), sane-"backendname"(5)

AUTHOR

       David Mosberger