dbh_passing_to_function

#!/usr/bin/perl

use DBI;
use warnings;
use strict;
use autodie;
use Term::ANSIColor qw(:constants);

# User-changable variables
my $database = "db_name";
my $table = "schema.table";
my $db_driver  = "Pg";
my $username = "postgres";
my $password = "password";

my $dbh = open_db($database, $table, $username, $password, $db_driver);

# close_db($dbh, $table);  # Case #1
close_db($dbh);          # Case #2

##############################################################

sub close_db {  # Disconnect the database
    # my $dbh = $_[0];  # Case #1
    my $dbh = @_;   # Case #2

    $dbh->disconnect() or die RED, "ERROR: The database could not be disconnected.\n       $DBI::errstr\n       Stopped$!";
    print "INFO: The database has been closed successfully.\n";
    return;
}

sub open_db {
    # Variables
    my $database; my $table; my $host = ""; my $user; my $port = ""; my $password; my $db_driver;
    my $dsn; my $dbh; my $sth;

    if (scalar(@_) == 5) {
        # Database name
        $database = "$_[0]";

        # Table name and optionally schema name
        $table = "$_[1]";

        # User, host and port
        if ("$_[2]" =~ /.*@.*/) {
            if ("$_[2]" =~ /.*:.*/) {
                # User name
                $user = "$_[2]";
                $user =~ s/^([^@]*).*$/$1/;

                # Host name
                $host = "$_[2]";
                $host =~ s/^[^@]*@([^:]*).*$/$1/;

                # Port
                $port = "$_[2]";
                $port =~ s/^[^:]*:(.*)$/$1/;
            } else {
                # User name
                $user = "$_[2]";
                $user =~ s/^([^@]*).*$/$1/;

                # Host name
                $host = "$_[2]";
                $host =~ s/^[^@]*@([^:]*).*$/$1/;
            }
        } else {
            # User name
            $user = "$_[2]";
            $user =~ s/^([^@]*).*$/$1/;
        }

        # Password
        $password = "$_[3]";

        # DB db_driver
        $db_driver = "$_[4]";
    } else {
        die RED, "ERROR: You have to supply database name, table name, user\@host:port, password and the database db_driver.\n       Stopped$!";
    }

    if ("$port" eq ""){
        if ("$host" eq ""){
            $dsn = "DBI:$db_driver:dbname = $database";
        } else {
            $dsn = "DBI:$db_driver:dbname = $database; host = $host";
        }
    } else {
        $dsn = "DBI:$db_driver:dbname = $database; host = $host; port = $port";
    }

    $dbh = DBI->connect($dsn, $user, $password, { RaiseError => 1 }) or die RED, "ERROR: The database could not be opened.\n       $DBI::errstr\n       Stopped$!";
    print "INFO: The database has been opened successfully.\n";
    return $dbh;
}