Table 4-21. cidr and inet Operators
| Operator | Description | Usage |
|---|---|---|
| < | Less than | inet '192.168.1.5' < inet '192.168.1.6' |
| <= | Less than or equal | inet '192.168.1.5' <= inet '192.168.1.5' |
| = | Equals | inet '192.168.1.5' = inet '192.168.1.5' |
| >= | Greater or equal | inet '192.168.1.5' >= inet '192.168.1.5' |
| > | Greater | inet '192.168.1.5' > inet '192.168.1.4' |
| <> | Not equal | inet '192.168.1.5' <> inet '192.168.1.4' |
| << | is contained within | inet '192.168.1.5' << inet '192.168.1/24' |
| <<= | is contained within or equals | inet '192.168.1/24' <<= inet '192.168.1/24' |
| >> | contains | inet'192.168.1/24' >> inet '192.168.1.5' |
| >>= | contains or equals | inet '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 4-22. cidr and inet Functions
| Function | Returns | Description | Example | Result |
|---|---|---|---|---|
| broadcast(inet) | inet | broadcast address for network | broadcast('192.168.1.5/24') | 192.168.1.255/24 |
| host(inet) | text | extract IP address as text | host('192.168.1.5/24') | 192.168.1.5 |
| masklen(inet) | integer | extract netmask length | masklen('192.168.1.5/24') | 24 |
| set_masklen(inet,integer) | inet | set netmask length for inet value | set_masklen('192.168.1.5/24',16) | 192.168.1.5/16 |
| netmask(inet) | inet | construct netmask for network | netmask('192.168.1.5/24') | 255.255.255.0 |
| network(inet) | cidr | extract network part of address | network('192.168.1.5/24') | 192.168.1.0/24 |
| text(inet) | text | extract IP address and masklen as text | text(inet '192.168.1.5') | 192.168.1.5/32 |
| abbrev(inet) | text | extract abbreviated display as text | abbrev(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. You can cast a text field to inet using normal casting syntax: inet(expression) or colname::inet.
Table 4-23. macaddr Functions
| Function | Returns | Description | Example | Result |
|---|---|---|---|---|
| trunc(macaddr) | macaddr | set last 3 bytes to zero | trunc(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.