9.10. Network Address Type Functions

Table 9-31 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 part is identical to or a subnet of the other.

Table 9-31. 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 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'

Table 9-32 shows the functions available for use with the cidr and inet types. The host, text, and abbrev functions are primarily intended to offer alternative display formats. You can cast a text value to inet using normal casting syntax: inet(expression) or colname::inet.

Table 9-32. cidr and inet Functions

FunctionReturn TypeDescriptionExampleResult
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
set_masklen(inet, integer)inetset netmask length for inet valueset_masklen('192.168.1.5/24', 16)192.168.1.5/16
netmask(inet)inetconstruct netmask for networknetmask('192.168.1.5/24')255.255.255.0
hostmask(inet)inetconstruct host mask for networkhostmask('192.168.23.20/30')0.0.0.3
network(inet)cidrextract network part of addressnetwork('192.168.1.5/24')192.168.1.0/24
text(inet)textextract IP address and netmask length as texttext(inet '192.168.1.5')192.168.1.5/32
abbrev(inet)textabbreviated display format as textabbrev(cidr '10.1.0.0/16')10.1/16

Table 9-33 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. The directory contrib/mac in the source distribution contains some utilities to create and maintain such an association table.

Table 9-33. 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.

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