=pod

=head1 NAME

engine - load and query engines

=head1 SYNOPSIS

B<openssl engine>
[ I<engine...> ]
[B<-v>]
[B<-vv>]
[B<-vvv>]
[B<-vvv>]
[B<-vvv>]
[B<-c>]
[B<-t>]
[B<-tt>]
[B<-pre> I<command>]
[B<-post> I<command>]
[ I<engine...> ]

=head1 DESCRIPTION

The B<engine> command is used to query the status and capabilities
of the specified B<engine>'s.
Engines may be speicifed before and after all other command-line flags.
Only those specified are queried.

=head1 OPTIONS

=over 4

=item B<-v> B<-vv> B<-vvv> B<-vvvv>

Provides information about each specified engine. The first flag lists
all the possible run-time control commands; the second adds a
description of each command; the third adds the input flags, and the
final option adds the internal input flags.

=item B<-c>

Lists the capabilities of each engine.

=item B<-t>

Tests if each specified engine is available, and displays the answer.

=item B<-tt>

Displays an error trace for any unavailable engine.

=item B<-pre> I<command>
=item B<-post> I<command>

Command-line configuration of engines.
The B<-pre> command is given to the engine before it is loaded and
the B<-post> command is given after the engine is loaded.
The I<command> is of the form I<cmd:val> where I<cmd> is the command,
and I<val> is the value for the command.
See the example below.

=back

=head1 EXAMPLE

To list all the commands available to a dynamic engine:

 % openssl engine -t -tt -vvvv dynamic
 (dynamic) Dynamic engine loading support
      [ unavailable ]
      SO_PATH: Specifies the path to the new ENGINE shared library
           (input flags): STRING
      NO_VCHECK: Specifies to continue even if version checking fails (boolean)
           (input flags): NUMERIC
      ID: Specifies an ENGINE id name for loading
           (input flags): STRING
      LIST_ADD: Whether to add a loaded ENGINE to the internal list (0=no,1=yes,2=mandatory)
           (input flags): NUMERIC
      DIR_LOAD: Specifies whether to load from 'DIR_ADD' directories (0=no,1=yes,2=mandatory)
           (input flags): NUMERIC
      DIR_ADD: Adds a directory from which ENGINEs can be loaded
           (input flags): STRING
      LOAD: Load up the ENGINE specified by other settings
           (input flags): NO_INPUT

To list the capabilities of the I<rsax> engine:

 % openssl engine -c
 (rsax) RSAX engine support
  [RSA]
 (dynamic) Dynamic engine loading support

=cut