| libtracefs(3) |
| ============= |
| |
| NAME |
| ---- |
| tracefs_option_enable, tracefs_option_disable, tracefs_option_name - |
| Various trace option functions. |
| |
| SYNOPSIS |
| -------- |
| [verse] |
| -- |
| *#include <tracefs.h>* |
| |
| int *tracefs_option_enable*(struct tracefs_instance pass:[*]_instance_, enum tracefs_option_id _id_); |
| int *tracefs_option_disable*(struct tracefs_instance pass:[*]_instance_, enum tracefs_option_id _id_); |
| const char pass:[*]*tracefs_option_name*(enum tracefs_option_id _id_); |
| -- |
| |
| DESCRIPTION |
| ----------- |
| This set of APIs can be used to enable and disable ftrace options and to get the name of an option. |
| |
| The *tracefs_option_enable()* function enables the option with _id_ in the given _instance_. If |
| _instance_ is NULL, the option is enabled in the top trace instance. |
| |
| The *tracefs_option_disable()* function disables the option with _id_ in the given _instance_. If |
| _instance_ is NULL, the option is disabled in the top trace instance. |
| |
| The *tracefs_option_name()* function returns a string, representing the option with _id_. The string |
| must *not* be freed. |
| |
| |
| RETURN VALUE |
| ------------ |
| The *tracefs_option_enable()* and *tracefs_option_disable()* functions return 0 if the state of the |
| option is set successfully, or -1 in case of an error. |
| |
| The *tracefs_option_name()* function returns string with option name, or "unknown" in case of an |
| error. The returned string must *not* be freed. |
| |
| EXAMPLE |
| ------- |
| [source,c] |
| -- |
| #include <tracefs.h> |
| ... |
| if (tracefs_option_enable(NULL, TRACEFS_OPTION_ANNOTATE)) { |
| /* Failed to enable annotate option in top trace instance */ |
| } |
| ... |
| if (tracefs_option_disable(NULL, TRACEFS_OPTION_CONTEXT_INFO)) { |
| /* Failed to disable context info option in top trace instance */ |
| } |
| ... |
| char *name = tracefs_option_name(TRACEFS_OPTION_FUNC_STACKTRACE); |
| if (strcmp(name, "unknown")) { |
| /* Cannot get the name of the option */ |
| } |
| |
| -- |
| FILES |
| ----- |
| [verse] |
| -- |
| *tracefs.h* |
| Header file to include in order to have access to the library APIs. |
| *-ltracefs* |
| Linker switch to add when building a program that uses the library. |
| -- |
| |
| SEE ALSO |
| -------- |
| *libtracefs*(3), |
| *libtraceevent*(3), |
| *trace-cmd*(1) |
| |
| AUTHOR |
| ------ |
| [verse] |
| -- |
| *Steven Rostedt* <rostedt@goodmis.org> |
| *Tzvetomir Stoyanov* <tz.stoyanov@gmail.com> |
| -- |
| REPORTING BUGS |
| -------------- |
| Report bugs to <linux-trace-devel@vger.kernel.org> |
| |
| LICENSE |
| ------- |
| libtracefs is Free Software licensed under the GNU LGPL 2.1 |
| |
| RESOURCES |
| --------- |
| https://git.kernel.org/pub/scm/libs/libtrace/libtracefs.git/ |
| |
| COPYING |
| ------- |
| Copyright \(C) 2020 VMware, Inc. Free use of this software is granted under |
| the terms of the GNU Public License (GPL). |
