Variables

You can use special variables in several places:

• mail_location setting and namespace locations

• static userdb and passwd-file userdb template strings

• LDAP and SQL userdb query strings

• log prefix for imap/pop3 process

• Plugin settings

The variables that work everywhere are:

• Variable	Long name	Description
  %%		'%' character
  %u	user	full username (e.g. user@domain)
  %n	username	user part in user@domain, same as %u if there's no domain
  %d	domain	domain part in user@domain, empty if user there's no domain
  %s	service	imap, pop3, smtp, deliver. (v1.0 uses uppercased IMAP and POP3)
  %p	pid	PID of the current process (login or imap/pop3 process)
  %l	lip	local IP address
  %r	rip	remote IP address

These variables work almost everywhere else except in Dovecot-auth (userdb queries/templates):

• Variable	Long name	Description
  %h	home	home directory. Use of ~/ is better whenever possible.
  %i	uid	UNIX UID of the user

These variables work only in Dovecot-auth:

• Variable	Long name	Description
  %w	password	plaintext password from plaintext authentication mechanism
  %m	mech	authentication mechanism, e.g. PLAIN (v1.0.rc27+)
  %a	lport	Local port (v1.1+)
  %b	rport	Remote port (v1.1+)
  %c	secured	"secured" string with SSL, TLS and localhost connections. Otherwise empty. (v1.0.rc27+)
  %k	cert	"valid" if client had sent a valid client certificate, otherwise empty. (v1.2.alpha4+)

These variables work only in login_log_format_elements setting:

• Variable	Long name	Description
  %m	mech	authentication mechanism, e.g. PLAIN
  %a	lport	Local port (v1.1+)
  %b	rport	Remote port (v1.1+)
  %c	secured	SSL, TLS or empty
  %k	ssl_security	SSL protocol and cipher information, e.g. "TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)" (v1.1.3+)
  %e	mail_pid	Mail process (imap/pop3) PID that handles the post-login connection (v1.2+)

Long variable names can be used with v1.2.alpha5+ like %{long_name}  or with L modifier: %L{long_name} .

Modifiers

You can apply a modifiers for each variable (e.g. %Ls = pop3):

• %L - lowercase
• %U - uppercase
• %E - escape '"', "'" and '\' characters by inserting '\' before them. Note that variables in SQL queries are automatically escaped, you don't need to use this modifier for them.
• %X - parse the variable as a base-10 number, and convert it to base-16 (hexadecimal)
• %R - reverse the string
• %H - take a 32bit hash of the variable and return it as hex. You can also limit the hash value. For example %256Hu gives values 0..ff. You might want padding also, so %2.256Hu gives 00..ff. This can be useful for example in dividing users automatically to multiple partitions.
  • %H hash function is a bit bad if all the strings end with the same text, so if you're hashing usernames being in user@domain form, you probably want to reverse the username to get better hash value variety, e.g. %3RHu.
• %M - return the string's MD5 sum
• %D - return "sub.domain.org" as "sub,dc=domain,dc=org" (for LDAP queries)
• %T - Trim trailing whitespace (v1.1.rc6+)

You can take a substring of the variable by giving optional offset followed by '.' and width after the '%' character. For example %2u gives first two characters of the username. %2.1u gives third character of the username.

If the offset is negative, it counts from the end, for example %-2.2i gives the UID mod 100 (last two characters of the UID printed in a string). If a positive offset points outside the value, empty string is returned, if a negative offset does then the string is taken from the start.

If the width is prefixed with zero, the string isn't truncated, but only padded with '0' character if the string is shorter. For example %04i may return "0001", "1000" and "12345". %1.04i for the same string would return "001", "000" and "2345".

The modifiers are applied from left-to-right order, except the substring is always taken from the final string.