39.4. PL/Perl 麯䔇噘匔埻麟

嘹埇傖彷䫘噘匔昼彖 %_SHARED 媺庻昄扞寙拸傼乕嚘䫘毕䂺施閘埇傖膆彄嘷嬉嚔臺䔇䫘变橘㔗

婋麵滇婔婻噌庆昄扞䔇冋床

CREATE OR REPLACE FUNCTION set_var(name text, val text) RETURNS text AS $$
    if ($_SHARED{$_[0]} = $_[1]) {
        return 'ok';
    } else {
        return "can't set shared variable $_[0] to $_[1]";
    }
$$ LANGUAGE plperl;

CREATE OR REPLACE FUNCTION get_var(name text) RETURNS text AS $$
    return $_SHARED{$_[0]};
$$ LANGUAGE plperl;

SELECT set_var('sample', 'Hello, PL/Perl!  How's tricks?');
SELECT get_var('sample');

婋麵滇婔婻嘪䫘傼乕嚘䫘䔇䘉冞崉溗底䔇冋床

CREATE OR REPLACE FUNCTION myfuncs() RETURNS void AS $$
    $_SHARED{myquote} = sub {
        my $arg = shift;
        $arg =~ s/(['\\])/\\$1/g;
        return "'$arg'";
    };
$$ LANGUAGE plperl;

SELECT myfuncs(); /* 彺哋寡庘昄 */

/* 傺䆋婔婻嘪䫘嚘䫘䔇庘昄䔇庘昄 */

CREATE OR REPLACE FUNCTION use_quote(TEXT) RETURNS text AS $$
    my $text_to_quote = shift;
    my $qfunc = $_SHARED{myquote};
    return &$qfunc($text_to_quote);
$$ LANGUAGE plperl;

套悩婉婘幯滷臂攓嘹埇傖䫘婔臯 return $_SHARED{myquote}->($_[0]); 傼敪婪麵䔇婬臯㔗