X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=doc%2Fman%2Flttng-enable-event.1.txt;h=92fd5f51f22d65910f951edbed665cfed84df63d;hb=980bb5fda2120f8d2a4e82fcf72be7cbbeb85fd2;hp=2230df059c8c512882efc9666409a290a8ad18d9;hpb=03c5529d5cb12b279866d2c3245712a639284ce8;p=lttng-tools.git diff --git a/doc/man/lttng-enable-event.1.txt b/doc/man/lttng-enable-event.1.txt index 2230df059..92fd5f51f 100644 --- a/doc/man/lttng-enable-event.1.txt +++ b/doc/man/lttng-enable-event.1.txt @@ -133,8 +133,9 @@ The available conditions for the Linux kernel domain are: (option:--probe or option:--function option's argument) which must match event source's equivalent. + -Wildcard using the `*` character are supported _at the end_ of -tracepoint and system call names. +You can use `*` characters at any place in the tracepoint or system +call name as wildcards to match zero or more characters. To use a +literal `*` character, use :escwc:. * Filter expression (option:--filter option) executed against the dynamic values of event fields at execution time that must evaluate @@ -146,10 +147,11 @@ The available conditions for the application domains are: * Tracepoint name ('EVENT' with option:--tracepoint option) which must match event source's equivalent. + -Wildcard using the `*` character are supported _at the end_ of -tracepoint names. When creating an event rule with a tracepoint name -containing a wildcard, specific tracepoint names can be excluded from -the match using the option:--exclude option. +You can use `*` characters at any place in the tracepoint name as +wildcards to match zero or more characters. To use a literal `*` +character, use :escwc:. When you create an event rule with a tracepoint +name containing a wildcard, you can exclude specific tracepoint names +from the match with the option:--exclude option. * Filter expression (option:--filter option) executed against the dynamic values of event fields at execution time that must evaluate @@ -176,10 +178,10 @@ argument named `*` (wildcard). [[filter-syntax]] Filter expression syntax ~~~~~~~~~~~~~~~~~~~~~~~~ -Filter expressions can be specified with the option:--filter option -when creating a new event rule. If the filter expression evaluates -to true when executed against the dynamic values of an event's fields -when tracing, the filtering condition passes. +A filter expression can be specified with the option:--filter option +when creating a new event rule. If the filter expression evaluates 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 @@ -216,13 +218,14 @@ The arithmetic and bitwise operators are :not: supported. The precedence table of the operators above is the same as the one of the C language. Parentheses are supported to bypass this. -The dynamic value of an event field is read by using its name as -a C identifier. +The dynamic value of an event field is read by using its name as a C +identifier. The dynamic value of a statically-known context field is read by prefixing its name with `$ctx.`. Statically-known context fields are context fields added to channels without the `$app.` prefix using the -man:lttng-add-context(1) command. +man:lttng-add-context(1) command. `$ctx.cpu_id` is also available as the +ID of the CPU which emits the event. The dynamic value of an application-specific context field is read by prefixing its name with `$app.` (follows the format used to add such a @@ -232,9 +235,9 @@ When a comparison includes a non existent event field, the whole filter expression evaluates to false (the event is discarded). 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 :escwc:. +literal strings between double quotes (`"`). You can use `*` characters +at any place in a literal string as wildcards to match zero or more +characters. To use a literal `*` character, use :escwc:. LTTng-UST enumeration fields can be compared to integer values (fields or constants). @@ -258,6 +261,10 @@ $ctx.procname == "lttng*" && (!flag || poel < 34) $app.my_provider:my_context == 17.34e9 || some_enum >= 14 --------------------------------------------------------- +--------------------------------------- +$ctx.cpu_id == 2 && filename != "*.log" +--------------------------------------- + [[log-levels]] Log levels @@ -411,9 +418,11 @@ Filtering and exclusion ~~~~~~~~~~~~~~~~~~~~~~~ option:-x 'EVENT'[,'EVENT']..., option:--exclude='EVENT'[,'EVENT']...:: Exclude events named 'EVENT' from the event rule. This option - can be used when the command's 'EVENT' argument contains a wildcard - (`*`) to exclude specific names. Only available with application - domains. + can be used when the command's 'EVENT' argument contains at least + one wildcard star (`*`) to exclude specific names. 'EVENT' can also + contain wildcard stars. To use a + literal `,` character, use :esccomma:. + Only available with the option:--userspace domain. option:-f 'EXPR', option:--filter='EXPR':: Add filter expression condition to the event rule. Expression 'EXPR'