is a program that speaks the server  side  of  SFTP  protocol  to
     stdout  and  expects client requests from stdin.  is not intended
     to be called directly, but from using the  option.   Command-line
     flags  to  should  be specified in the declaration.  See for more
     information.  Valid options are: specifies an alternate  starting
     directory  for  users.   The  pathname  may contain the following
     tokens that are expanded at runtime: %% is replaced by a  literal
     '%',  %d  is  replaced  by  the  home directory of the user being
     authenticated, and %u is replaced by the username of  that  user.
     The  default is to use the user's home directory.  This option is
     useful in conjunction with the option.  Causes to  print  logging
     information to stderr instead of syslog for debugging.  Specifies
     the facility code that is used when  logging  messages  from  The
     possible  values are: DAEMON, USER, AUTH, LOCAL0, LOCAL1, LOCAL2,
     LOCAL3, LOCAL4, LOCAL5, LOCAL6, LOCAL7.   The  default  is  AUTH.
     Displays  usage  information.   Specifies  which messages will be
     logged by The possible values are:  QUIET,  FATAL,  ERROR,  INFO,
     VERBOSE, DEBUG, DEBUG1, DEBUG2, and DEBUG3.  INFO and VERBOSE log
     transactions that performs on behalf of the  client.   DEBUG  and
     DEBUG1  are  equivalent.   DEBUG2  and DEBUG3 each specify higher
     levels of debugging output.  The default  is  ERROR.   Specify  a
     comma-separated list of SFTP protocol requests that are banned by
     the server.  will reply to any denied  request  with  a  failure.
     The  flag  can  be used to determine the supported request types.
     If both denied and allowed lists are specified, then  the  denied
     list  is  applied  before  the  allowed  list.   Specify a comma-
     separated list of SFTP protocol requests that  are  permitted  by
     the  server.   All request types that are not on the allowed list
     will be logged and replied to with a failure message.  Care  must
     be  taken  when  using  this feature to ensure that requests made
     implicitly  by  SFTP  clients  are  permitted.   Query   protocol
     features  supported  by  At  present the only feature that may be
     queried is which may be used to deny or allow  specific  requests
     (flags  and  respectively).  Places this instance of into a read-
     only mode.  Attempts to open files for writing, as well as  other
     operations  that  change  the  state  of  the filesystem, will be
     denied.  Sets an explicit to be applied  to  newly-created  files
     and  directories,  instead  of  the user's default mask.  On some
     systems, must be able to access for logging to work, and  use  of
     in  a  chroot  configuration  therefore requires that establish a
     logging socket inside the chroot directory.  first appeared in