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
Operator | Description | Example |
---|
< | is less than | inet '192.168.1.5' < inet '192.168.1.6' |
<= | is 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' |
>= | is greater or equal | inet '192.168.1.5' >= inet '192.168.1.5' |
> | is greater than | inet '192.168.1.5' > inet '192.168.1.4' |
<> | is not equal | inet '192.168.1.5' <> inet '192.168.1.4' |
<< | is contained by | inet '192.168.1.5' << inet '192.168.1/24' |
<<= | is contained by 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' |
&& | contains or is contained by | inet '192.168.1/24' && inet '192.168.1.80/28' |
~ | bitwise NOT | ~ inet '192.168.1.6' |
& | bitwise AND | inet '192.168.1.6' & inet '0.0.0.255' |
| | bitwise OR | inet '192.168.1.6' | inet '0.0.0.255' |
+ | addition | inet '192.168.1.6' + 25 |
- | subtraction | inet '192.168.1.43' - 36 |
- | subtraction | inet '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
Function | Return Type | Description | Example | Result |
---|
abbrev(inet )
| text | abbreviated display format as text | abbrev(inet '10.1.0.0/16') | 10.1.0.0/16 |
abbrev(cidr )
| text | abbreviated display format as text | abbrev(cidr '10.1.0.0/16') | 10.1/16 |
broadcast(inet )
| inet | broadcast address for network | broadcast('192.168.1.5/24') | 192.168.1.255/24 |
family(inet )
| int | extract family of address; 4 for IPv4,
6 for IPv6 | family('::1') | 6 |
host(inet )
| text | extract IP address as text | host('192.168.1.5/24') | 192.168.1.5 |
hostmask(inet )
| inet | construct host mask for network | hostmask('192.168.23.20/30') | 0.0.0.3 |
masklen(inet )
| int | extract netmask length | masklen('192.168.1.5/24') | 24 |
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 |
set_masklen(inet , int )
| inet | set netmask length for inet value | set_masklen('192.168.1.5/24', 16) | 192.168.1.5/16 |
set_masklen(cidr , int )
| cidr | set netmask length for cidr value | set_masklen('192.168.1.0/24'::cidr, 16) | 192.168.0.0/16 |
text(inet )
| text | extract IP address and netmask length as text | text(inet '192.168.1.5') | 192.168.1.5/32 |
inet_same_family(inet , inet )
| boolean | are the addresses from the same family? | inet_same_family('192.168.1.5/24', '::1') | false |
inet_merge(inet , inet )
| cidr | the smallest network which includes both of the given networks | inet_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
Function | Return Type | 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 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
Function | Return Type | Description | Example | Result |
---|
trunc(macaddr8 )
| macaddr8 | set last 5 bytes to zero | trunc(macaddr8 '12:34:56:78:90:ab:cd:ef') | 12:34:56:00:00:00:00:00 |
macaddr8_set7bit(macaddr8 )
| macaddr8 | set 7th bit to one, also known as modified EUI-64, for inclusion in an IPv6 address | macaddr8_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.