I've almost got it, but I can't get the 'auto' line right. I think this is a pretty no brainer question, but alas,I am a noob. 


auto lo
iface lo inet loopback

auto eth0               <--This line needs eth1, too!

iface eth0 inet dhcp

iface eth1 inet static
address 192.168.0.4
netmask 255.255.255.0
network 192.168.0.0
broadcast 192.168.0.255
gateway 192.168.0.1

[download]

This is my table select output

 my $sth = $dbh->prepare( "SELECT host, name, type, address, netmask, 
+gateway FROM $table_name" );
#(PRINTED)
app17, eth1, static, 192.168.0.2, 255.255.255.0, 192.168.0.1
app15, eth0, dhcp, , , 
app15, eth1, static, 192.168.0.4, 255.255.255.0, 192.168.0.1
app12, eth1, static, 192.168.0.5, 255.255.255.0, 192.168.0.1

[download]

My first instinct was to create a hash keyed off of hostname, but there's duplicates, then I thought IP address, but those that are DHCP don't have them.

Anyway here's some of the code: 

my @ifaces;
my @hosts;
while ( my @row = $sth->fetchrow_array )
{
    my $host = $row[0];
    my $iface = $row[1];
    my $type = $row[2];
    my $address = $row[3];
    my $netmask = $row[4];
    my $gateway = $row[5];

    push( @hosts, "$host" );
########### Here's what I can't get right #############
    while ( @hosts )
    {
         push( @ifaces, "$iface");
         @ifaces = pop( @ifaces );
         last;
    }
########### Above is what I can't get right #############
my $tmp_file = "/tmp/interfaces.$host";
my $loopback_string = "auto lo\niface lo inet loopback\n\nauto";
    open(my $interfaces_file,"+>>$tmp_file") or die "Unable to open $t
+mp_file: $!\n"; 
    if ( -z $tmp_file )
    {
        print {$interfaces_file} "$loopback_string @ifaces\n\n";
    }
    
    if ($type eq "dhcp")
    {
        print {$interfaces_file}  "iface $iface inet $type\n\n";
    }
    else
    {
        print {$interfaces_file} "iface $iface inet $type\naddress $ad
+dress\nnetmask $netmask\nnetwork 192.168.0.0\nbroadcast 192.168.0.255
+\ngateway $gateway\n";
close($interfaces_file) or die "Can't close it\n";
    }
}
$dbh->disconnect;

[download]

In reply to Trying to create a linux interfaces file out of rows from a database. by jduffany

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