NAME

       Ace::Local - use giface, tace or gifaceclient to open a local connection to an Ace
       database

SYNOPSIS

         use Ace::Local
         my $ace = Ace::Local->connect(-path=>'/usr/local/acedb/elegans');
         $ace->query('find author Se*');
         die "Query unsuccessful" unless $ace->status;
         $ace->query('show');
         while ($ace->encore) {
           print $ace->read;
         }

DESCRIPTION

       This class is provided for low-level access to local (non-networked) Ace databases via the
       giface program.  You will generally not need to access it directly.  Use Ace.pm instead.

       For the sake of completeness, the method can also use the aceclient program for its
       access.  However the Ace::AceDB class is more efficient for this purpose.

METHODS

   connect()
         $accessor = Ace::Local->connect(-path=>$path_to_database);

       Connect to the database at the indicated path using giface and return a connection object
       (an "accessor").  Giface must be on the current search path.  Multiple accessors may be
       open simultaneously.

       Arguments include:

       -path
           Path to the database (location of the "wspec/" directory).

       -program
           Used to indicate the location of the desired giface or gifaceclient executable.  You
           may also use tace or aceclient, but in that case the asGIF() functionality will nog
           work.  Can be used to override the search path.

       -host
           Used when invoking gifaceclient.  Indicates the host to connect to.

       -port
           Used when invoking gifaceclient.  Indicates the port to connect to.

       -nosync
           Ordinarily Ace::Local synchronizes with the tace/giface prompt, throwing out all
           warnings and copyright messages.  If this is set, Ace::Local will not do so.  In this
           case you must call the low_read() method until it returns undef in order to
           synchronize.

   query()
         $status = $accessor->query('query string');

       Send the query string to the server and return a true value if successful.  You must then
       call read() repeatedly in order to fetch the query result.

   read()
       Read the result from the last query sent to the server and return it as a string.  ACE may
       return the result in pieces, breaking between whole objects.  You may need to read
       repeatedly in order to fetch the entire result.  Canonical example:

         $accessor->query("find Sequence D*");
         die "Got an error ",$accessor->error() if $accessor->status == STATUS_ERROR;
         while ($accessor->status == STATUS_PENDING) {
            $result .= $accessor->read;
         }

   low_read()
       Read whatever data's available, or undef if none.  This is only used by the ace.pl
       replacement for giface/tace.

   status()
       Return the status code from the last operation.  Status codes are exported by default when
       you use Ace.pm.  The status codes you may see are:

         STATUS_WAITING    The server is waiting for a query.
         STATUS_PENDING    A query has been sent and Ace is waiting for
                           you to read() the result.
         STATUS_ERROR      A communications or syntax error has occurred

   error()
       May return a more detailed error code supplied by Ace.  Error checking is not fully
       implemented.

   encore()
       This method will return true after you have performed one or more read() operations, and
       indicates that there is more data to read.  encore() is functionally equivalent to:

          $encore = $accessor->status == STATUS_PENDING;

       In fact, this is how it's implemented.

   auto_save()
       Sets or queries the auto_save variable.  If true, the "save" command will be issued
       automatically before the connection to the database is severed.  The default is true.

       Examples:

          $accessor->auto_save(1);
          $flag = $accessor->auto_save;

SEE ALSO

       Ace, Ace::Object, Ace::Iterator, Ace::Model

AUTHOR

       Lincoln Stein <lstein@w3.org> with extensive help from Jean Thierry-Mieg
       <mieg@kaa.crbm.cnrs-mop.fr>

       Copyright (c) 1997-1998, Lincoln D. Stein

       This library is free software; you can redistribute it and/or modify it under the same
       terms as Perl itself.  See DISCLAIMER.txt for disclaimers of warranty.