EvmFilter(5)EvmFilter(5)NAMEEvmFilter - Event filter
An event filter is a specification of a set of interesting events.
Event subscribers use filters to tell the EVM daemon which events they
want to receive - for example, one subscriber may be only interested in
receiving events reporting hardware errors, while another may want to
receive all high-priority events, regardless of what they are report‐
ing. If a subscriber does not set a filter, it will receive no events.
The Event Viewer and some of the EVM user commands also use filters to
select events for viewing or processing.
A filter is an ASCII character string - it can be very simple or arbi‐
trarily complex. Complex filters are created by combining simple fil‐
A simple filter has the following format: [keyword expr] | all | 1 |
none | 0
The format of expr is specific to the type of filter. The left and
right square brackets ([ and ]) are required. Keywords may be speci‐
fied in any mix of upper and lower case, and where the underscore char‐
acter (_) is included in a full-length keyword (as in host_name), it
may be omitted. Keywords may be abbreviated, and in the following
paragraphs the minimum abbreviation for each is indicated by upper-case
Possible values for keyword and the associated expr are: Selects events
with a name matching the event-name-specifier. Names are considered to
match when the event name matches as many components as included in the
The event-name-specifier may include the * and the ? characters
as wildcards in any component position. The * represents 0 or
more components with any value. The ? represents exactly one
component. Any event-name-specifier includes an implied trail‐
ing wildcard. Only events with a priority meeting the specified
evaluation will be passed. The integer value may be 0 to 700,
inclusive. See the following table for a description of equal‐
ity-operator. May be specified as prio. All events with a
timestamp that is within the time-range-specifier are passed.
See the description of time-range-specifier. May be specified
as time. Selects events that meet the age specification. See
the description of age-specifier. The equality-operator must
specify less-than or less-than-or-equal, meaning "newer than",
or greater-than or greater-than-or-equal, meaning "older than."
The "equal" or "not equal" operators are not allowed. All
events with a timestamp that is earlier than the absolute-time-
specifier are passed. See the description of absolute-time-
specifier. All events with a timestamp that is equal to or
later than the absolute-time-specifier are passed. See the
description of absolute-time-specifier. All events posted from
the machine host-name are passed. May be specified as host.
All events posted from the cluster cluster-name are passed. May
be specified as cluster. All events with an event_id meeting
the specified evaluation will be passed. See EvmEvent(5) for a
description of the event_id. See the following table for a
description of equality-operator. The EVent_id keyword may be
abbreviated to ID. A filter value of none or 0 passes no
events. A filter value of all or 1 passes all events.
The available equality-operator specifiers and their alternate repre‐
sentations are shown in the following table. The alternate representa‐
tions may be used in any mix of upper and lower case.
Operator Alternate Meaning
= eq Equal
> gt Greater Than
< lt Less Than
>= ge Greater Than or Equal
<= le Less Than or Equal
!= ne Not Equal
An age-specifier comprises an integer value followed immediately by one
of the letters w (weeks), d (days), h (hours), m (minutes) or s (sec‐
onds). An age-specifier produces an absolute time value relative to
the present time, and is most likely to be useful in retrieving histor‐
ical events through evmget or the event viewer. It is not meaningful
to use an age-specifier when setting a filter for use by the EVM logger
If a period of weeks is specified, the period is converted to days by
multiplying it by 7. When calculating an absolute time for an age
specified in weeks or days, the first day is always regarded as the
period from the previous midnight until the present time, and earlier
days are counted from midnight to midnight. For example, if an age-
specifier of 1d is given, events are selected relative to 12:00 a.m.
on the same day. A value of 2d would select events relative to 12:00
a.m. the previous day. A value of 0d is valid, and is equivalent to
1d. See the following examples for more information.
If a period of hours, minutes or seconds is specified, an absolute time
is calculated by subtracting the age from the current time, without
regard to day boundaries. For example, if an age-specifier of 24h is
given at 15:23:14, events are selected relative to 15:23:14 on the pre‐
A time-range-specifier consists of seven colon-separated fields in the
following format: year:month-of-year:day-of-month:day-of-
Any component in the time range may be replaced by an asterisk (*)
character as a wildcard, meaning that any value in this component will
match the filter. You can specify multiple discrete values for a compo‐
nent by separating them with a comma. You can specify a range by using
a hyphen to separate the starting and ending values for the range.
An absolute-time-specifier is very similar to the time-range-specifier.
It has only six components, and does not allow the use of wild cards.
It has the following format: year:month-of-year:day-of-month:hours:min‐
In both forms of time specification, the range of values for each com‐
ponent is shown in the following table.
year 1970 to 2030
month-of-year 1 to 12
day-of-month 1 to 31
day-of-week 0 (Sun) to 6
hours 0 to 23
minutes 0 to 59
seconds 0 to 59
Any expression may be inverted (logically negated) by the use of the
NOT operator, the exclamation mark (!) or the keyword NOT.
A complex filter is composed of two or more simple filters, combined
using the AND (& or keyword AND) and OR (| or keyword OR) logical oper‐
ators. Component filter expressions may be grouped in parentheses ((
and )) to set the precedence of test operations. The order of prece‐
dence of logical and grouping operators (highest to lowest) is: ( ) ! &
Event filters can be direct or indirect. A direct filter is a text
string appearing at the point of filter specification. An indirect fil‐
ter is contained in a file, and is referred to using the following syn‐
See evmfilterfile(4) for more information about using indirect filters.
If an event being evaluated does not contain the item being compared in
a filter expression, the expression always yields no match. For exam‐
ple, if the timestamp item is missing from the event and you include
the before keyword in a filter string, that part of the filter will
return no match.
Successive versions of EVM may evolve the filter syntax by adding new
keywords or operators. If you use EVM's remote connection facilities
to connect to a system running an older version of EVM, and you attempt
to retrieve or subscribe for events using a filter with syntax that is
not supported by the older version, you will receive a response indi‐
cating that the filter is invalid. To determine what syntax is sup‐
ported by the older system, log into the system and view this reference
The following table shows a number of filter specifications, and the
interpretation given to each.
Filter String Interpretation
"[name *]" Any named event.
"[name myco.*]" All events with names that start
"![name myco.*]" All events with names that do not
start with myco.
"[name ?.?.?]" Any event with a name that has at
least three components.
"[name myco.myapp.*]" Any event with a name that has the
first two components myco.myapp.
"[name myco.myapp]" Any event with a name that has the
first two components myco.myapp.
Identical in meaning to the previous
"[name sys.unix.syslog]" Events which have sys.unix.syslog as
the first three components of the
"[name myco.myapp.*.showme]" Any event name that starts with the
components myco.myapp and ends with
showme, no matter how many compo‐
nents are included between.
"[age < 1d]" Any event posted today.
"[age < 4w]" Any event posted within the last 4
"[age lt 30s]" Any event posted within the last 30
"[age gt 1d]" Any event posted before today.
"[time 2000:6:1:*:*:*:*]" Any event posted on June 1, 2000.
"[time 2000:6:1,3:*:*:*:*]" Any event posted on June 1 or June
"[time 2000:6:1-3:*:*:*:*]" Any event posted between June 1 and
June 3, 2000.
"[time 2000:6:1-3,5-7:*:*:*:*]" Any event posted between June 1 and
June 3, 2000, or between June 5 and
June 7, 2000, inclusive.
"[time *:*:*:*:00-02:*:*]" All events occurring between mid‐
night and 2:59:59 a.m., inclusive.
"[since 2000:6:1:03:00:00]" All events occurring after 3:00 a.m.
on June 1, 2000.
"[before 2000:6:1:03:00:00]" All events occurring before 3:00
a.m. on June 1, 2000.
"[prio > 500]" All events with priority greater
"[name myco.myapp] & [pri >= 500]" All events that have names starting
with myco.myapp and priority at
"[name myco.myapp] | [pri >= 500]" All events that have names starting
with myco.myapp or that have prior‐
ity at least 500.
"[name sys.unix.syslog] & [age < All syslog events occurring today or
"[name sys.unix.syslog] and [time All syslog events occurring on June
2000:6:1-3:*:*:*:*]" 1, 2 or 3, 2000.
"none" Passes no events.
"0" Passes no events.
"all" Passes all events.
"1" Passes all events.
"@sys" Specifies an indirect filter. The
filter string is the default filter
contained in a filter file named sys
"@sys:advfs" Specifies an indirect filter. The
filter string is the filter named
advfs contained in a filter file
named sys or sys.evf.
Commands: evmget(1), evmshow(1), evmwatch(1)
Routines: EvmConnSubscribe(3), EvmFilterCreate(3), EvmFilterDestroy(3),
EvmFilterIsFile(3), EvmFilterReadFile(3), EvmFilterSet(3), EvmFil‐
Event Management: EVM(5)
EVM Events: EvmEvent(5)EvmFilter(5)