Expressions
Expressions are used for the filter, warning, critical and ok arguments.
Syntax
The basic syntax is <attribute> <operator> <value>. For a list and explanation
of allowed operators see the operator list.
The list of possible attributes is documented along with each check plugin.
ex.:
filter="status = 'started'"
critical="count >= 1"
Logical Operator
To combine multiple expressions you can use logical operator and brackets.
| Operator | Alias | Description |
|---|---|---|
and | && | Logical and operator |
or | || | Logical or operator |
ex.:
filter="(status = 'started' or status = 'pending') and usage > 5%"
Operator
| Operator | Alias / Safe expression | Types | Description |
|---|---|---|---|
= | ==, is, eq | Strings, Numbers | Matches on exact equality, ex.: status = 'started' |
!= | is not, ne | Strings, Numbers | Matches if value is not exactly equal. ex.: 5 != 3 |
like | Strings | Matches if value contains the condition (substring match), ex.: status like "pend" | |
unlike | not like | Strings | Matches if value does not contain the substring, ex.: status unlike "stopped" |
ilike | Strings | Matches a case insensitive substring, ex.: name ilike "WMI" | |
not ilike | Strings | Matches if a case insensitive substring cannot be found, ex.: name not ilike "WMI" | |
~ | regex, regexp | Strings | Performs a regular expression match, ex.: status ~ '^pend' |
!~ | not regex, not regexp | Strings | Performs a inverse regular expression match, ex.: status !~ 'stop' |
~~ | regexi, regexpi | Strings | Performs a case insensitive regular expression match, ex.: status ~~ '^pend'. An alternative way is to use //i as in status ~ /^pend/i |
!~~ | not regexi, not regexpi | Strings | Performs a inverse case insensitive regular expression match, ex.: status !~~ 'stop' |
< | lt | Numbers | Matches lower than numbers, ex.: usage < 5% |
<= | le, lte | Numbers | Matches lower or equal numbers, ex.: usage <= 5% |
> | gt | Numbers | Matches greater than numbers, ex.: usage > 5% |
>= | ge, gte | Numbers | Matches greater or equal numbers, ex.: usage >= 5% |
in | Strings | Matches if element is in list ex.: status in ('start', 'pending') | |
not in | Strings | Matches if element is not in list ex.: status not in ('stopped', 'starting') |