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 9-37 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.

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.

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