Ace::Local(3) User Contributed Perl Documentation Ace::Local(3)NAMEAce::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.
METHODSconnect()
$accessor = Ace::Local->connect(-path=>$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.
perl v5.14.1 2005-04-20 Ace::Local(3)