X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=doc%2Fman%2Ftracelog.3.txt;h=3c071d3779140da402cbf3cb9882f933d299be4e;hb=53f7d0d7404de911dd62dff06f08539e33ea7519;hp=1281ce7c8d940d5ec35d26055e3ed13d8c2fc3af;hpb=636cf2a01500b8bef5a5959b4f1d3a9a7222b39a;p=lttng-ust.git diff --git a/doc/man/tracelog.3.txt b/doc/man/tracelog.3.txt index 1281ce7c..3c071d37 100644 --- a/doc/man/tracelog.3.txt +++ b/doc/man/tracelog.3.txt @@ -1,3 +1,6 @@ +// SPDX-FileCopyrightText: 2016 Philippe Proulx +// SPDX-License-Identifier: CC-BY-4.0 +// tracelog(3) =========== :object-type: macro @@ -16,139 +19,17 @@ SYNOPSIS [verse] #define *tracelog*('level', 'fmt', ...) -Link with `-llttng-ust`. +Link with `-llttng-ust -llttng-ust-common`. DESCRIPTION ----------- -The LTTng-UST `tracelog()` API allows you to trace your application with -the help of a simple man:printf(3)-like macro, with an additional -parameter for the desired log level. The 'fmt' argument is passed -directly to the 'fmt' parameter of man:vasprintf(3), as well as -the optional parameters following 'fmt'. +The `tracelog()` macro is part of version{nbsp}0 of the LTTng-UST API +(see the ``Compatibility with previous APIs'' section of +man:lttng-ust(3)). -The purpose of `tracelog()` is to ease the migration from logging to -tracing. - -The available values for the 'level' parameter are: - -include::log-levels.txt[] - -To use `tracelog()`, 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()` 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()` 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()` -call, use man:tracef(3) instead. - -See also the <> section below for important -limitations to consider when using `tracelog()`. - - -[[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 ----- - -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) which is part of version{nbsp}1 +of the API and has the `lttng_ust_` namespace. include::common-footer.txt[] @@ -160,7 +41,5 @@ include::common-authors.txt[] SEE ALSO -------- -man:tracef(3), -man:lttng-ust(3), -man:lttng(1), -man:printf(3) +man:lttng_ust_tracelog(3), +man:lttng_ust_vtracelog(3)