tracefs_option_enable - Various trace option functions.

NAME  SYNOPSIS  DESCRIPTION  RETURN VALUE  EXAMPLE  FILES  SEE ALSO  AUTHOR  REPORTING BUGS  LICENSE  RESOURCES  COPYING  NOTES 

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NAME

tracefs_option_enable, tracefs_option_disable, tracefs_option_name − Various trace option functions.

SYNOPSIS

#include <tracefs.h>

int tracefs_option_enable(struct tracefs_instance *instance, enum tracefs_option_id id);
int tracefs_option_disable(struct tracefs_instance *instance, enum tracefs_option_id id);
const char *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

#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

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

Steven Rostedt <[email protected] [1] >
Tzvetomir Stoyanov <[email protected] [2] >

REPORTING BUGS

Report bugs to <linux−trace−[email protected] [3] >

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).

NOTES

1.

[email protected]

mailto:[email protected]

2.

[email protected]

mailto:[email protected]

3.

[email protected]

mailto:[email protected]

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