X-Git-Url: https://git.lttng.org/?p=lttng-ust.git;a=blobdiff_plain;f=doc%2Fman%2Ftracelog.3.txt;h=13284636fdc48ec8a512f4677bef5e0098957613;hp=1f97a0bdd68b092c4bfa7d93df49b7b1681b91c1;hb=5b1163c6cf674c6461cc1e0ad1211924df7af789;hpb=e436e84d48332d559fe60c1a5eba81f03e9f38f9 diff --git a/doc/man/tracelog.3.txt b/doc/man/tracelog.3.txt index 1f97a0bd..13284636 100644 --- a/doc/man/tracelog.3.txt +++ b/doc/man/tracelog.3.txt @@ -22,143 +22,13 @@ Link with `-llttng-ust -llttng-ust-common`. DESCRIPTION ----------- -The LTTng-UST `tracelog()` and `vtracelog()` API allows you to trace -your application with the help of simple man:printf(3)-like and -man:vprintf(3)-like macros, with an additional parameter for the desired -log level. +The `tracelog()` and `vtracelog()` macros are part of version{nbsp}0 of +the LTTng-UST API (see the ``Compatibility with previous APIs'' section +of man:lttng-ust(3)). -The 'fmt' argument is passed directly as the 'fmt' parameter of -man:vasprintf(3), as well as: - -For `tracelog()`:: - The optional parameters following 'fmt'. - -For `vtracelog()`:: - The 'ap' parameter as the 'ap' parameter of man:vasprintf(3) - (`va_list` type). - -The purpose of `tracelog()` and `vtracelog()` is to ease the migration -from logging to tracing. - -The available values for the 'level' parameter are: - -include::log-levels.txt[] - -To use `tracelog()` or `vtracelog()`, include `` where -you need it, and link your application with `liblttng-ust`. See the -<> section below for a complete usage example. - -Once your application is instrumented with `tracelog()` and/or -`vtracelog()` calls and ready to run, use man:lttng-enable-event(1) to -enable the `lttng_ust_tracelog:*` event. You can isolate specific log -levels with the nloption:--loglevel and nloption:--loglevel-only options -of this command. - -The `tracelog()` and `vtracelog()` events contain the following fields: - -[options="header"] -|=== -|Field name |Description - -|`line` -|Line in source file where `tracelog()` was called. - -|`file` -|Source file from which `tracelog()` was called. - -|`func` -|Function name from which `tracelog()` was called. - -|`msg` -|Formatted string output. -|=== - -If you do not need to attach a specific log level to a -`tracelog()`/`vtracelog()` call, use man:tracef(3) instead. - -See also the <> section below for important -limitations to consider when using `tracelog()` or `vtracelog()`. - - -[[example]] -EXAMPLE -------- -Here's a usage example of `tracelog()`: - -------------------------------------------------------------------- -#include -#include - -int main(int argc, char *argv[]) -{ - int i; - - if (argc < 2) { - tracelog(TRACE_CRIT, "Not enough arguments: %d", argc); - return EXIT_FAILURE; - } - - tracelog(TRACE_INFO, "Starting app with %d arguments", argc); - - for (i = 0; i < argc; i++) { - tracelog(TRACE_DEBUG, "Argument %d: %s", i, argv[i]); - } - - tracelog(TRACE_INFO, "Exiting app"); - - return EXIT_SUCCESS; -} -------------------------------------------------------------------- - -This C source file, saved as `app.c`, can be compiled into a program -like this: - -[role="term"] ----- -$ cc -o app app.c -llttng-ust -llttng-ust-common ----- - -You can create an LTTng tracing session, enable all the `tracelog()` -events, and start the created tracing session like this: - -[role="term"] ----- -$ lttng create my-session -$ lttng enable-event --userspace 'lttng_ust_tracelog:*' -$ lttng start ----- - -Or you can enable `tracelog()` events matching a log level at least -as severe as a given log level: - -[role="term"] ----- -$ lttng enable-event --userspace 'lttng_ust_tracelog:*' \ - --loglevel=TRACE_INFO ----- - -Next, start the program to be traced: - -[role="term"] ----- -$ ./app a few arguments passed to this application ----- - -Finally, stop the tracing session, and inspect the recorded events: - -[role="term"] ----- -$ lttng stop -$ lttng view ----- - - -[[limitations]] -LIMITATIONS ------------ -:macro-name: tracelog - -include::tracef-tracelog-limitations.txt[] +Prefer using man:lttng_ust_tracelog(3) and man:lttng_ust_vtracelog(3) +which are part of version{nbsp}1 of the API and have the `lttng_ust_` +namespace. include::common-footer.txt[] @@ -170,8 +40,5 @@ include::common-authors.txt[] SEE ALSO -------- -man:tracef(3), -man:vtracef(3), -man:lttng-ust(3), -man:lttng(1), -man:printf(3) +man:lttng_ust_tracelog(3), +man:lttng_ust_vtracelog(3)