tep_load_plugins(3) — Linux manual page
LIBTRACEEVENT(3) libtraceevent Manual LIBTRACEEVENT(3)
NAME
tep_load_plugins, tep_unload_plugins, tep_load_plugins_hook,
tep_add_plugin_path, tep_plugin_add_option - Load / unload
traceevent plugins.
SYNOPSIS
#include <event-parse.h>
struct tep_plugin_list *tep_load_plugins(struct tep_handle *tep);
void tep_unload_plugins(struct tep_plugin_list *plugin_list, struct tep_handle *tep);
void tep_load_plugins_hook(struct tep_handle *tep, const char *suffix,
void (*load_plugin)(struct tep_handle *tep,
const char *path,
const char *name,
void *data),
void *data);
int tep_add_plugin_path(struct tep_handle *tep, char *path,
enum tep_plugin_load_priority prio);
int tep_plugin_add_option(const char *name, const char *val);
DESCRIPTION
The tep_load_plugins() function loads all plugins, located in the
plugin directories. The tep argument is trace event parser
context. The plugin directories are :
- Directories, specified in tep→plugins_dir with priority TEP_PLUGIN_FIRST
- System’s plugin directory, defined at the library compile time. It
depends on the library installation prefix and usually is
(install_preffix)/lib/traceevent/plugins
- Directory, defined by the environment variable TRACEEVENT_PLUGIN_DIR
- User’s plugin directory, located at ~/.local/lib/traceevent/plugins
- Directories, specified in tep→plugins_dir with priority TEP_PLUGIN_LAST
Loading of plugins can be controlled by the tep_flags, using the
tep_set_flag() API:
TEP_DISABLE_SYS_PLUGINS - do not load plugins, located in
the system’s plugin directory.
TEP_DISABLE_PLUGINS - do not load any plugins.
The tep_set_flag() API needs to be called before
tep_load_plugins(), if loading of all plugins is not the desired
case.
The tep_unload_plugins() function unloads the plugins, previously
loaded by tep_load_plugins(). The tep argument is trace event
parser context. The plugin_list is the list of loaded plugins,
returned by the tep_load_plugins() function.
The tep_load_plugins_hook() function walks through all
directories with plugins and calls user specified load_plugin()
hook for each plugin file. Only files with given suffix are
considered to be plugins. The data is a user specified context,
passed to load_plugin(). Directories and the walk order are the
same as in tep_load_plugins() API.
The tep_add_plugin_path() functions adds additional directories
with plugins in the tep→plugins_dir list. It must be called
before tep_load_plugins() in order for the plugins from the new
directories to be loaded. The tep argument is the trace event
parser context. The path is the full path to the new plugin
directory. The prio argument specifies the loading priority order
for the new directory of plugins. The loading priority is
important in case of different versions of the same plugin
located in multiple plugin directories.The last loaded plugin
wins. The priority can be:
TEP_PLUGIN_FIRST - Load plugins from this directory first
TEP_PLUGIN_LAST - Load plugins from this directory last
Where the plugins in TEP_PLUGIN_LAST" will take precedence over
the plugins in the other directories.
The tep_plugin_add_option() sets options defined by a plugin. The
name is the name of the option to set to val. Plugins can add
options to change its behavior and tep_plugin_add_option() is
used by the application to make those modifications.
RETURN VALUE
The tep_load_plugins() function returns a list of successfully
loaded plugins, or NULL in case no plugins are loaded. The
tep_add_plugin_path() function returns -1 in case of an error, 0
otherwise.
EXAMPLE
#include <event-parse.h>
...
struct tep_handle *tep = tep_alloc();
...
tep_add_plugin_path(tep, "~/dev_plugins", TEP_PLUGIN_LAST);
...
struct tep_plugin_list *plugins = tep_load_plugins(tep);
if (plugins == NULL) {
/* no plugins are loaded */
}
...
tep_unload_plugins(plugins, tep);
...
void print_plugin(struct tep_handle *tep, const char *path,
const char *name, void *data)
{
pritnf("Found libtraceevent plugin %s/%s\n", path, name);
}
...
tep_load_plugins_hook(tep, ".so", print_plugin, NULL);
...
FILES
event-parse.h
Header file to include in order to have access to the library APIs.
-ltraceevent
Linker switch to add when building a program that uses the library.
SEE ALSO
libtraceevent(3), trace-cmd(1), tep_set_flag(3)
AUTHOR
Steven Rostedt <rostedt@goodmis.org[1]>, author of libtraceevent.
Tzvetomir Stoyanov <tz.stoyanov@gmail.com[2]>, author of this man page.
REPORTING BUGS
Report bugs to <linux-trace-devel@vger.kernel.org[3]>
LICENSE
libtraceevent is Free Software licensed under the GNU LGPL 2.1
RESOURCES
https://git.kernel.org/pub/scm/libs/libtrace/libtraceevent.git/
NOTES
1. rostedt@goodmis.org
mailto:rostedt@goodmis.org
2. tz.stoyanov@gmail.com
mailto:tz.stoyanov@gmail.com
3. linux-trace-devel@vger.kernel.org
mailto:linux-trace-devel@vger.kernel.org
COLOPHON
This page is part of the libtraceevent (Linux kernel trace event
library) project. Information about the project can be found at
⟨https://www.trace-cmd.org/⟩. If you have a bug report for this
manual page, see ⟨https://www.trace-cmd.org/⟩. This page was
obtained from the project's upstream Git repository
⟨https://git.kernel.org/pub/scm/libs/libtrace/libtraceevent.git⟩
on 2024-06-14. (At that time, the date of the most recent commit
that was found in the repository was 2024-05-17.) If you
discover any rendering problems in this HTML version of the page,
or you believe there is a better or more up-to-date source for
the page, or you have corrections or improvements to the
information in this COLOPHON (which is not part of the original
manual page), send a mail to man-pages@man7.org