use POSIX qw( mkfifo );

    my $svitok_truby;
    mkfifo( $svitok_truby, 0700 ) || die "Ошибка создания трубы  $svitok_truby  : $!";


    my @args = ('/usr/bin/mplayer', '-slave', "-input file=$svitok_truby", '/tmp/1.flac');
    local $SIG{CHLD} = "IGNORE";

    my $pid = fork();
    die "Fork failed\n" unless defined $pid;
    if ($pid == 0) {
        $| = 1;
        exec @args;
    }

    open (my $FIFO, '>', $svitok_truby)  || die "can't open $svitok_truby: $!";
    while(read STDIN, my($char), 1) {
        print $FIFO $char;
    }
    close($FIFO);