1LIBTRACEEVENT(3) libtraceevent Manual LIBTRACEEVENT(3)
2
6 tep_load_plugins, tep_unload_plugins, tep_load_plugins_hook,
7 tep_add_plugin_path - Load / unload traceevent plugins.
8
10 #include <event-parse.h>
11 struct tep_plugin_list *tep_load_plugins(struct tep_handle *tep);
13 void tep_unload_plugins(struct tep_plugin_list *plugin_list, struct tep_handle *tep);
14 void tep_load_plugins_hook(struct tep_handle *tep, const char *suffix,
15 void (*load_plugin)(struct tep_handle *tep,
16 const char *path,
17 const char *name,
18 void *data),
19 void *data);
20 int tep_add_plugin_path(struct tep_handle *tep, char *path,
21 enum tep_plugin_load_priority prio);
22
24 The tep_load_plugins() function loads all plugins, located in the
25 plugin directories. The tep argument is trace event parser context. The
26 plugin directories are :
27 - Directories, specified in tep→plugins_dir with priority TEP_PLUGIN_FIRST
29 - System’s plugin directory, defined at the library compile time. It
30 depends on the library installation prefix and usually is
31 (install_preffix)/lib/traceevent/plugins
32 - Directory, defined by the environment variable TRACEEVENT_PLUGIN_DIR
33 - User’s plugin directory, located at ~/.local/lib/traceevent/plugins
34 - Directories, specified in tep→plugins_dir with priority TEP_PLUGIN_LAST
35 Loading of plugins can be controlled by the tep_flags, using the
37 tep_set_flag() API:
38 TEP_DISABLE_SYS_PLUGINS - do not load plugins, located in
40 the system’s plugin directory.
41 TEP_DISABLE_PLUGINS - do not load any plugins.
42 The tep_set_flag() API needs to be called before tep_load_plugins(), if
44 loading of all plugins is not the desired case.
45 The tep_unload_plugins() function unloads the plugins, previously
47 loaded by tep_load_plugins(). The tep argument is trace event parser
48 context. The plugin_list is the list of loaded plugins, returned by the
49 tep_load_plugins() function.
50 The tep_load_plugins_hook() function walks through all directories with
52 plugins and calls user specified load_plugin() hook for each plugin
53 file. Only files with given suffix are considered to be plugins. The
54 data is a user specified context, passed to load_plugin(). Directories
55 and the walk order are the same as in tep_load_plugins() API.
56 The tep_add_plugin_path() functions adds additional directories with
58 plugins in the tep→plugins_dir list. It must be called before
59 tep_load_plugins() in order for the plugins from the new directories to
60 be loaded. The tep argument is the trace event parser context. The path
61 is the full path to the new plugin directory. The prio argument
62 specifies the loading priority order for the new directory of plugins.
63 The loading priority is important in case of different versions of the
64 same plugin located in multiple plugin directories.The last loaded
65 plugin wins. The priority can be:
66 TEP_PLUGIN_FIRST - Load plugins from this directory first
68 TEP_PLUGIN_LAST - Load plugins from this directory last
69 Where the plugins in TEP_PLUGIN_LAST" will take precedence over the
71 plugins in the other directories.
72
74 The tep_load_plugins() function returns a list of successfully loaded
75 plugins, or NULL in case no plugins are loaded. The
76 tep_add_plugin_path() function returns -1 in case of an error, 0
77 otherwise.
78
80 #include <event-parse.h>
81 ...
82 struct tep_handle *tep = tep_alloc();
83 ...
84 tep_add_plugin_path(tep, "~/dev_plugins", TEP_PLUGIN_LAST);
85 ...
86 struct tep_plugin_list *plugins = tep_load_plugins(tep);
87 if (plugins == NULL) {
88 /* no plugins are loaded */
89 }
90 ...
91 tep_unload_plugins(plugins, tep);
92 ...
93 void print_plugin(struct tep_handle *tep, const char *path,
94 const char *name, void *data)
95 {
96 pritnf("Found libtraceevent plugin %s/%s\n", path, name);
97 }
98 ...
99 tep_load_plugins_hook(tep, ".so", print_plugin, NULL);
100 ...
101
103 event-parse.h
104 Header file to include in order to have access to the library APIs.
105 -ltraceevent
106 Linker switch to add when building a program that uses the library.
107
109 libtraceevent(3), trace-cmd(1), tep_set_flag(3)
110
112 Steven Rostedt <rostedt@goodmis.org[1]>, author of libtraceevent.
113 Tzvetomir Stoyanov <tz.stoyanov@gmail.com[2]>, author of this man page.
114
116 Report bugs to <linux-trace-devel@vger.kernel.org[3]>
117
119 libtraceevent is Free Software licensed under the GNU LGPL 2.1
120
122 https://git.kernel.org/pub/scm/libs/libtrace/libtraceevent.git/
123
125 1. rostedt@goodmis.org
126 mailto:rostedt@goodmis.org
127 2. tz.stoyanov@gmail.com
129 mailto:tz.stoyanov@gmail.com
130 3. linux-trace-devel@vger.kernel.org
132 mailto:linux-trace-devel@vger.kernel.org
133libtraceevent 1.2.1 07/22/2021 LIBTRACEEVENT(3)