Provided by: sane-airscan_0.99.27-1build1_amd64 bug


       sane-airscan - SANE backend for AirScan (eSCL) and WSD scanners and MFP


       The sane-airscan is the universal backend for "driverless" document scanning. Currently it
       supports two protocols:

           1. eSCL, also known as AirScan or AirPrint scan
           2. WSD, also known as WS-Scan


       The sane-airscan loads its configuration files from the following places:

           1. /etc/sane.d/airscan.conf
           2. /etc/sane.d/airscan.d/*

       The configuration file syntax is very similar to the  .INI  file  syntax.  It  consist  of
       sections,  each  section  contains  some  variables.  Comments  are  started  from  # or ;
       characters and continies until end of line

           # This is a comment
           [section 1]
           variable 1 = value 1  ; and another comment
           variable 2 = value 2

       Leading and trailing spaces of variable name  and  value  are  striped.  If  you  want  to
       preserve them, put name or value into quotes ("like this").


       If  scanner  and  computer  are  connected to the same LAN segment, everything expected to
       "just work" out of box, without any need of manual configuration.

       However, in some cases manual configuration can be useful. For example:

           1. If computer and scanner are connected via IP router
           2. There are a lot of devices on a corporate network, but
              only few of them are interesting
           3. Automatic discovery works unreliable

       To manually configure a device, add the following section to the configuration file:

           "Kyocera eSCL" =, eSCL
           "Kyocera WSD" =, WSD
           "Device I do not want to see" = disable

       The [devices] section contains all manually configured devices, one line per  device,  and
       each  line  contains  a  device name on a left side of equation and device URL on a rights
       side, followed by protocol (eSCL or WSD). If protocol is omitted, eSCL is assumed. You may
       also disable particular device by using the disable keyword instead of URL.

       In  addition,  you can manually configure a device by directly passing its URL in a device
       name without adding it to the configuration file. This takes  the  format  protocol:Device
       Name:URL.     The     examples     above     could     be    written    as    escl:Kyocera
       eSCL:                    and                     wsd:Kyocera

       To  figure  out  URLs  of  available  devices,  the  simplest  way  is  to  run a supplied
       airscan-discover tool on a computer connected with scanner to the  same  LAN  segment.  On
       success,  this  program will dump to its standard output a list of discovered devices in a
       format suitable for inclusion into the configuration file.

       If running airscan-discover on same LAN segment as a scanner is  not  possible,  you  will
       have  to  follow  a hard way. Your administrator must know device IP address, consult your
       device manual for the eSCL port, and the URL path component most likely  is  the  "/eSCL",
       though  on some devices it may differ. Discovering WSD URLs doing this way is much harder,
       because it is very difficult to guess TCP port and URL path, that in a case of eSCL.

       For   eSCL   devices,   the   URL   can   also   use   the   unix://   scheme,   such   as
       unix://scanner.sock/eSCL. The "host" from the URL is a file name that will be searched for
       in the directory specified by socket_dir (see below). When connecting to the scanner,  all
       traffic will be sent to the specified UNIX socket instead of a TCP connection.


       Miscellaneous  options  all goes to the [options] section. Currently the following options
       are supported:

           ; If there are a lot of scanners around and you are only
           ; interested in few of them, disable auto discovery and
           ; configure scanners manually
           discovery = enable | disable

           ; Choose what SANE apps will show in a list of devices:
           ; scanner network name (the default) or hardware model name
           model = network | hardware

           ; If device supports both eSCL and WSD protocol, sane-airscan
           ; may either choose the "best" protocol automatically, or
           ; expose all variants for user, allowing manual protocol selection.
           ; The default is "auto"
           protocol = auto | manual

           ; Discovery of WSD devices may be "fast" or "full". The "fast"
           ; mode works as fast as DNS-SD discovery, but in some cases
           ; may be unreliable. The "full" mode is slow and reliable.
           ; This is also possible to disable automatic discovery
           ; of WSD devices. The default is "fast".
           ws-discovery = fast | full | off

           ; Scanners that use the unix:// schema in their URL can only specify a
           ; socket name (not a full path).  The name will be searched for in the
           ; directory specified here. The default is /var/run.
           socket_dir = /path/to/directory


       This feature can be useful, if you are on a very big network and have  a  lot  of  devices
       around you, while interesting only in a few of them.

           model = "Xerox*"       ; blacklist by model name
           name  = "HP*"          ; blacklist by network name
           ip    =    ; blacklist by address
           ip    = ; blacklist the whole subnet

       Network  names  come  from  DNS-SD,  WS-Discovery  doesn´t  provide  this information. For
       filtering by network name to work, Avahi must be enabled and device must  be  discoverable
       via  DNS-SD (not necessarily as a scanner, it´s enough if WSD scanner is discoverable as a
       printer via DNS-SD).

       Blacklisting only affects automatic discovery,  and  doesn´t  affect  manually  configured


       sane-airscan  provides  very  good  instrumentation  for  troubleshooting without physical
       access to the problemmatic device.

       Debugging facilities can be controlled using the  [debug]  section  of  the  configuration

           ; Enable or disable console logging
           enable = false | true

           ; Enable protocol trace and configure output directory
           ; for trace files. Like in shell, to specify path relative to
           ; the home directory, start it with tilda character, followed
           ; by slash, i.e., "~/airscan/trace". The directory will
           ; be created automatically.
           trace = path

           ; Hex dump all traffic to the trace file (very verbose!)
           hexdump = false | true


       /etc/sane.d/airscan.conf, /etc/sane.d/airscan.d/*
              The backend configuration files

              The shared library implementing this backend


              This  variable  if set to true or non-zero numerical value, enables debug messages,
              that are printed to stdout

              This  variable  alters  the  search  path  for  configuration  files.  This  is   a
              colon-separated  list  of  directories.  These  directories  are  searched  for the
              airscan.conf configuration file and for  the  airscan.d  subdirectory,  before  the
              standard path (/etc/sane.d) is searched.


       If  you  have  found  a  bug,  please  file  a  GitHub  issue  on  a  GitHub project page:


       sane(7), scanimage(1), xsane(1), airscan-discover(1)


       Alexander Pevzner <>

                                             May 2021                             SANE-AIRSCAN(5)