4.9. Network Address Type Functions

Table 4-18. cidr and inet Operators

OperatorDescriptionUsage
< Less thaninet '192.168.1.5' < inet '192.168.1.6'
<= Less than or equalinet '192.168.1.5' <= inet '192.168.1.5'
= Equalsinet '192.168.1.5' = inet '192.168.1.5'
>= Greater or equalinet '192.168.1.5' >= inet '192.168.1.5'
> Greaterinet '192.168.1.5' > inet '192.168.1.4'
<> Not equalinet '192.168.1.5' <> inet '192.168.1.4'
<< is contained withininet '192.168.1.5' << inet '192.168.1/24'
<<= is contained within or equalsinet '192.168.1/24' <<= inet '192.168.1/24'
>> containsinet'192.168.1/24' >> inet '192.168.1.5'
>>= contains or equalsinet '192.168.1/24' >>= inet '192.168.1/24'

All of the operators for inet can be applied to cidr values as well. The operators <<, <<=, >>, >>= test for subnet inclusion: they consider only the network parts of the two addresses, ignoring any host part, and determine whether one network part is identical to or a subnet of the other.

Table 4-19. cidr and inet Functions

FunctionReturnsDescriptionExampleResult
broadcast(inet)inetbroadcast address for networkbroadcast('192.168.1.5/24')192.168.1.255/24
host(inet)textextract IP address as texthost('192.168.1.5/24')192.168.1.5
masklen(inet)integerextract netmask lengthmasklen('192.168.1.5/24')24
netmask(inet)inetconstruct netmask for networknetmask('192.168.1.5/24')255.255.255.0
network(inet)cidrextract network part of addressnetwork('192.168.1.5/24')192.168.1.0/24
text(inet)textextract IP address and masklen as texttext(inet '192.168.1.5')192.168.1.5/32
abbrev(inet)textextract abbreviated display as textabbrev(cidr '10.1.0.0/16')10.1/16

All of the functions for inet can be applied to cidr values as well. The host(), text(), and abbrev() functions are primarily intended to offer alternative display formats.

Table 4-20. macaddr Functions

FunctionReturnsDescriptionExampleResult
trunc(macaddr)macaddrset last 3 bytes to zerotrunc(macaddr '12:34:56:78:90:ab')12:34:56:00:00:00

The function trunc(macaddr) returns a MAC address with the last 3 bytes set to 0. This can be used to associate the remaining prefix with a manufacturer. The directory contrib/mac in the source distribution contains some utilities to create and maintain such an association table.

The macaddr type also supports the standard relational operators (>, <=, etc.) for lexicographical ordering.