Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help
sane-dll(5)		  SANE Scanner Access Now Easy		     sane-dll(5)

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 back-
     ends may be loaded at runtime.  In the latter case, adding  support  for  a
     new  backend  simply  involves  installing the relevant library in /usr/lo-
     cal/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 sup-
     port 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  de-
     vice 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

     It is also possible to add a file in /usr/local/etc/sane.d/dll.d that  con-
     tains  the  list  of backends to be added. Backends mentioned in a file in-
     cluded in this directory will  be	added  before  any  backends  listed  in
     dll.conf.	 Files	in /usr/local/etc/sane.d/dll.d can be freely named. They
     shall follow the format conventions as apply for dll.conf.

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

     /usr/local/etc/sane.d/dll.conf
	    The  backend  configuration  file (see also description of SANE_CON-
	    FIG_DIR below).

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

     /usr/local/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.	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 /usr/local/etc/sane.d.  If the
	    value of the environment variable ends with the directory  separator
	    character,	then  the default directories are searched after the ex-
	    plicitly specified	directories.   For  example,  setting  SANE_CON-
	    FIG_DIR to "/tmp/config:" would result in directories tmp/config, .,
	    and /usr/local/etc/sane.d being searched (in this order).

     SANE_DEBUG_DLL
	    If	the  library was compiled with debug support enabled, this envi-
	    ronment variable controls the debug level for this backend.  E.g., a
	    value of 128 requests all debug output to be printed.  Smaller  lev-
	    els 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

				   13 Jul 2008			     sane-dll(5)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=sane-dll&sektion=5&manpath=FreeBSD+Ports+15.1.quarterly>

home | help