9.12. Network Address Functions and Operators

Table 9.36 shows the operators available for the cidr and inet types. The operators << , <<= , >> , >>= , and && test for subnet inclusion. They consider only the network parts of the two addresses (ignoring any host part) and determine whether one network is identical to or a subnet of the other.

Table 9.36. cidr and inet Operators

OperatorDescriptionExample
<is less thaninet '192.168.1.5' < inet '192.168.1.6'
<=is less than or equalinet '192.168.1.5' <= inet '192.168.1.5'
=equalsinet '192.168.1.5' = inet '192.168.1.5'
>=is greater or equalinet '192.168.1.5' >= inet '192.168.1.5'
>is greater thaninet '192.168.1.5' > inet '192.168.1.4'
<>is not equalinet '192.168.1.5' <> inet '192.168.1.4'
<<is contained byinet '192.168.1.5' << inet '192.168.1/24'
<<=is contained by 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'
&&contains or is contained byinet '192.168.1/24' && inet '192.168.1.80/28'
~bitwise NOT~ inet '192.168.1.6'
&bitwise ANDinet '192.168.1.6' & inet '0.0.0.255'
|bitwise ORinet '192.168.1.6' | inet '0.0.0.255'
+additioninet '192.168.1.6' + 25
-subtractioninet '192.168.1.43' - 36
-subtractioninet '192.168.1.43' - inet '192.168.1.19'

Table 9.37 shows the functions available for use with the cidr and inet types. The abbrev , host , and text functions are primarily intended to offer alternative display formats.

Table 9.37. cidr and inet Functions

FunctionReturn TypeDescriptionExampleResult
abbrev(inet)textabbreviated display format as textabbrev(inet '10.1.0.0/16')10.1.0.0/16
abbrev(cidr)textabbreviated display format as textabbrev(cidr '10.1.0.0/16')10.1/16
broadcast(inet)inetbroadcast address for networkbroadcast('192.168.1.5/24')192.168.1.255/24
family(inet)intextract family of address; 4 for IPv4, 6 for IPv6family('::1')6
host(inet)textextract IP address as texthost('192.168.1.5/24')192.168.1.5
hostmask(inet)inetconstruct host mask for networkhostmask('192.168.23.20/30')0.0.0.3
masklen(inet)intextract 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
set_masklen(inet, int)inetset netmask length for inet valueset_masklen('192.168.1.5/24', 16)192.168.1.5/16
set_masklen(cidr, int)cidrset netmask length for cidr valueset_masklen('192.168.1.0/24'::cidr, 16)192.168.0.0/16
text(inet)textextract IP address and netmask length as texttext(inet '192.168.1.5')192.168.1.5/32
inet_same_family(inet, inet)booleanare the addresses from the same family?inet_same_family('192.168.1.5/24', '::1')false
inet_merge(inet, inet)cidrthe smallest network which includes both of the given networksinet_merge('192.168.1.5/24', '192.168.2.5/24')192.168.0.0/22

Any cidr value can be cast to inet implicitly or explicitly; therefore, the functions shown above as operating on inet also work on cidr values. (Where there are separate functions for inet and cidr , it is because the behavior should be different for the two cases.) Also, it is permitted to cast an inet value to cidr . When this is done, any bits to the right of the netmask are silently zeroed to create a valid cidr value. In addition, you can cast a text value to inet or cidr using normal casting syntax: for example, inet(expression) or colname::cidr .

Table 9.38 shows the functions available for use with the macaddr type. The function trunc(macaddr) returns a MAC address with the last 3 bytes set to zero. This can be used to associate the remaining prefix with a manufacturer.

Table 9.38. macaddr Functions

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

The macaddr type also supports the standard relational operators ( > , <= , etc.) for lexicographical ordering, and the bitwise arithmetic operators ( ~ , & and | ) for NOT, AND and OR.

Table 9.39 shows the functions available for use with the macaddr8 type. The function trunc(macaddr8) returns a MAC address with the last 5 bytes set to zero. This can be used to associate the remaining prefix with a manufacturer.

Table 9.39. macaddr8 Functions

FunctionReturn TypeDescriptionExampleResult
trunc(macaddr8)macaddr8set last 5 bytes to zerotrunc(macaddr8 '12:34:56:78:90:ab:cd:ef')12:34:56:00:00:00:00:00
macaddr8_set7bit(macaddr8)macaddr8set 7th bit to one, also known as modified EUI-64, for inclusion in an IPv6 addressmacaddr8_set7bit(macaddr8 '00:34:56:ab:cd:ef')02:34:56:ff:fe:ab:cd:ef

The macaddr8 type also supports the standard relational operators ( > , <= , etc.) for ordering, and the bitwise arithmetic operators ( ~ , & and | ) for NOT, AND and OR.