Enabling assembly bind logging on .NET

To enable assembly bind logging, set the registry value below.

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Fusion]
"EnableLog"=dword:00000001

Save the above contents to a file with a .reg extension and double-click it to register in the registry.

To disable it, delete the registry value using regedit.exe.

Assembly probing, Fusion and fuslogvw in 5 minutes - B# .NET Blog

Setting the maximum send / receive size of Postfix

/etc/postfix/main.cf

message_size_limit = 20480000

The default when message_size_limit is not specified is 10240000 (10MB).

For complete parameter list of main.cf, see the postconf(5) man page.

$ man 5 postconf
message_size_limit (default: 10240000)
       The maximal size in bytes of a message, including envelope information.

Caution

Be careful when changing message_size_limit.
message_size_limit must not be larger than mailbox_size_limit.
If message_size_limit is larger than mailbox_size_limit、you can't receive any messages.

The default of mailbox_size_limit is 51200000 (50MB).
Zero means no limit.

mailbox_size_limit = 0
mailbox_size_limit (default: 51200000)
       The  maximal  size  of any local(8) individual mailbox or maildir file, or zero (no limit).  In fact, this limits the size of any
       file that is written to upon local delivery, including files written by external commands  that  are  executed  by  the  local(8)
       delivery agent.

       This limit must not be smaller than the message size limit.

map(collect) method on an array of ActiveRecord object

Let's assume there is a model `Member` and the table `members` has a column `name`.

class Member < ActiveRecord::Base
end

You can use map (or collect) method as shown below.

members = Member.find(:all)
member_names = members.map(&:name)

This is thanks to the definition of Symbol#to_proc in ActiveSupport as shown below.

class Symbol
  def to_proc
    Proc.new { |obj, *args| obj.send(self, *args) }
  end
end

The code that uses map method above is equal to the code below.

members = Member.find(:all)
member_names = members.map { |member| member.name }

Allowing ftp with iptables

When you allow ftp with iptables, allowing port 21 like below is not enough to accept LIST command.

# iptables -A INPUT -p tcp --dport 21 -j ACCEPT

You need to load 2 modules ip_conntrack_ftp and ip_nat_ftp.
Edit /etc/sysconfig/iptables-config and add the following and they will be loaded automatically.

IPTABLES_MODULES="ip_conntrack_ftp ip_nat_ftp"

Then restart iptables.

# service iptables restart

Make sure the modules are loaded.

# lsmod
Module                  Size  Used by
nf_nat_ftp              7361  0 
nf_conntrack_ftp       13761  1 nf_nat_ftp
...(omit)

Source: iptablesでftpを通す