


sane-dll(5)                                           sane-dll(5)


NNAAMMEE
       sane-dll - SANE dynamic backend loader

DDEESSCCRRIIPPTTIIOONN
       The ssaannee--ddllll 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 ssaannee--ddllll 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 _@_L_I_B_D_I_R_@ and adding  an
       entry to the _d_l_l_._c_o_n_f configuration file.  In other words,
       no applications need to be modified or recompiled  to  add
       support for new devices.

DDEEVVIICCEE NNAAMMEESS
       This backend expects device names of the form:

              _b_a_c_k_e_n_d:_d_e_v_i_c_e

       Where _b_a_c_k_e_n_d is the name of the backend and _d_e_v_i_c_e 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  _d_e_v_i_c_e
       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).

CCOONNFFIIGGUURRAATTIIOONN
       The  contents  of  the  _d_l_l_._c_o_n_f file is a list of backend
       names that may be loaded dynamically upon  demand.   Empty
       lines and lines starting with a hash mark (#) are ignored.
       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
       PPRREELLOOAADDAABBLLEE__BBAACCKKEENNDDSS  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.

FFIILLEESS




                           13 May 1998                          1





sane-dll(5)                                           sane-dll(5)


       _@_C_O_N_F_I_G_D_I_R_@_/_d_l_l_._c_o_n_f
              The backend configuration file (see  also  descrip-
              tion of SSAANNEE__CCOONNFFIIGG__DDIIRR below).

       _@_L_I_B_D_I_R_@_/_l_i_b_s_a_n_e_-_d_l_l_._a
              The static library implementing this backend.

       _@_L_I_B_D_I_R_@_/_l_i_b_s_a_n_e_-_d_l_l_._s_o
              The  shared library implementing this backend (pre-
              sent on systems that support dynamic loading).

EENNVVIIRROONNMMEENNTT
       SSAANNEE__CCOONNFFIIGG__DDIIRR
              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 @CONFIGDIR@.  If the value of the
              environment variable ends with the directory  sepa-
              rator  character,  then the default directories are
              searched after the  explicitly  specified  directo-
              ries.   For  example,  setting  SSAANNEE__CCOONNFFIIGG__DDIIRR  to
              "/tmp/config:"   would   result   in    directories
              "tmp/config", ".", and "@CONFIGDIR@" being searched
              (in this order).

       SSAANNEE__DDEEBBUUGG__DDLLLL
              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.

AAUUTTHHOORR
       David Mosberger



















                           13 May 1998                          2


