NAME
evmsort — sort events
SYNOPSIS
evmsort
[-A
[-t
show_template]]
[-s
sport_spec]
[filename |
-]
DESCRIPTION
The
evmsort
command reads and sorts a stream of EVM events.
By default, events are read from
stdin,
and are sorted into ascending timestamp order.
Sorted events are written to the command's
stdout
stream in the form of raw EVM events.
The sort order can be specified by supplying a
sort_spec,
either through the
-s
option or by setting the environment variable
EVM_SORT_SPEC
to the required specification.
The specification is a character string of the form:
@key_item
[ +|- ]
[:@
key_item[
+|- ]]
The
key_item
is the name of any EVM standard data item and the
@
character is optional.
If the special
key_item
@@
is specified, the event's
format
data item is expanded as described in the
evmshow(1)
manpage, and the resulting string is used as the sort key.
The optional trailing
+
or
-
character indicates ascending
(+}
or descending
(-)
sort.
By default, items are sorted in ascending order.
Multiple items in the string are separated by colon characters
(:).
The left-most
key_item
in the specification is the most significant key.
If a
key_item
that is included in the sort specification is not present in an event
read from the input stream, the item is considered to have a low value
for that event.
For example,
if input events are being sorted in ascending order according to their
name
data items, and one event does not contain a name, that event
appears first in the output stream.
If the
-A
option is specified,
evmsort
automatically starts
evmshow
and pipes the sorted event stream into it, producing a sorted and
formatted display of events.
If a
-t show_template
argument is also specified with
-A,
the specified template string is passed to
evmshow
through its own
-t
option.
See the
evmshow(1)
manpage for more information.
Options
- -A
Automatically starts
evmshow
to produce a formatted display of the sorted events.
- -s sort_spec
The specification to be used in sorting events.
See the
DESCRIPTION
section for the syntax of the
sort_spec,
and for details of the default sort order.
- -t show_template
Template string to be passed to
evmshow
if the
-A
option is also specified.
If the
-A
option is not specified, this argument is ignored.
See the
evmshow(1)
manpage for a description of the template string.
Operands
- filename
Reads event sources from
filename.
If
filename
is omitted, or is specified as
-,
event sources are read from
stdin.
EXTERNAL INFLUENCES
Environment Variables
The following environment variables affect the execution of
evmsort:
- EVM_SORT_SPEC
This variable contains a string formatted as described for a
sort_spec.
If the
-s
option is omitted, the string is used as the
sort_spec.
RETURN VALUES
The following exit values are returned:
- 0
Successful completion.
- not 0
An error occurred.
EXAMPLES
The following example retrieves all events with a priority of 300 or
greater, sorts them into descending order of priority (most urgent event
first) and then ascending order of time (oldest event first), and
automatically runs
evmshow
to display them.
evmget -f '[priority >= 300]' | evmsort -s "@priority-:@timestamp" |
evmshow -t "@priority @timestamp @@"
The following example yields a list of all events, sorted with the latest event first within
name.
evmget | evmsort -s "@name:@timestamp-" |
evmshow -t "@name @timestamp @@"
The following example yields a list of all events, sorted first in order
of their formatted messages and then sorted in ascending order of time.
Events are passed to
evmshow
for display and subsequently to the
more
command for viewing.
evmget | evmsort -A -s "@@:@timestamp" -t "@timestamp @@" | more
WARNINGS
The
evmsort
command rejects attempts to output raw events to a terminal device.
Printable version
