Create or enable Linux kernel event rules:
[verse]
-*lttng* ['GENERAL OPTIONS'] *enable-event* option:--kernel
+*lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *enable-event* option:--kernel
[option:--probe='SOURCE' | option:--function='SOURCE' | option:--syscall]
[option:--filter='EXPR'] [option:--session='SESSION']
[option:--channel='CHANNEL'] 'EVENT'[,'EVENT']...
Create or enable an "all" Linux kernel event rule:
[verse]
-*lttng* ['GENERAL OPTIONS'] *enable-event* option:--kernel option:--all [option:--syscall]
+*lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *enable-event* option:--kernel option:--all [option:--syscall]
[option:--filter='EXPR'] [option:--session='SESSION'] [option:--channel='CHANNEL']
Create or enable application event rules:
[verse]
-*lttng* ['GENERAL OPTIONS'] *enable-event*
+*lttng* ['linkgenoptions:(GENERAL OPTIONS)'] *enable-event*
(option:--userspace | option:--jul | option:--log4j | option:--python)
[option:--filter='EXPR'] [option:--exclude='EVENT'[,'EVENT']...]
[option:--loglevel='LOGLEVEL' | option:--loglevel-only='LOGLEVEL']
For example, consider the following commands:
+[role="term"]
----------------------------------------------------------------
lttng enable-event --userspace hello:world
lttng enable-event --userspace hello:world --loglevel=TRACE_INFO
to true when executed against the dynamic values of an event's fields
when tracing, the filtering condition passes.
+NOTE: Make sure to **single-quote** the filter expression when running
+the command from a shell, as filter expressions typically include
+characters having a special meaning for most shells.
+
The filter expression syntax is very similar to C language conditional
expressions (expressions that can be evaluated by an `if` statement).
C integer and floating point number constants are supported, as well as
literal strings between double quotes (`"`). Literal strings can contain
a wildcard character (`*`) at the end to match more than one string.
-This wildcard can be escaped using `\\*`.
+This wildcard can be escaped using :escwc:.
LTTng-UST enumeration fields can be compared to integer values (fields
or constants).