'\" t
.\"     Title: libtraceevent
.\"    Author: [see the "AUTHOR" section]
.\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>
.\"      Date: 01/14/2024
.\"    Manual: libtraceevent Manual
.\"    Source: libtraceevent 1.8.2
.\"  Language: English
.\"
.TH "LIBTRACEEVENT" "3" "01/14/2024" "libtraceevent 1\&.8\&.2" "libtraceevent Manual"
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.SH "NAME"
tep_load_plugins, tep_unload_plugins, tep_load_plugins_hook, tep_add_plugin_path, tep_plugin_add_option \- Load / unload traceevent plugins\&.
.SH "SYNOPSIS"
.sp
.nf
\fB#include <event\-parse\&.h>\fR

struct tep_plugin_list *\fBtep_load_plugins\fR(struct tep_handle *\fItep\fR);
void \fBtep_unload_plugins\fR(struct tep_plugin_list *\fIplugin_list\fR, struct tep_handle *\fItep\fR);
void \fBtep_load_plugins_hook\fR(struct tep_handle *\fItep\fR, const char *\fIsuffix\fR,
                           void (*\fIload_plugin\fR)(struct tep_handle *tep,
                                               const char *path,
                                               const char *name,
                                               void *data),
                           void *\fIdata\fR);
int \fBtep_add_plugin_path\fR(struct tep_handle *tep, char *path,
                          enum tep_plugin_load_priority prio);
int \fBtep_plugin_add_option\fR(const char *\fIname\fR, const char *\fIval\fR);
.fi
.SH "DESCRIPTION"
.sp
The \fBtep_load_plugins()\fR function loads all plugins, located in the plugin directories\&. The \fItep\fR argument is trace event parser context\&. The plugin directories are :
.sp
.if n \{\
.RS 4
.\}
.nf
        \- Directories, specified in \fItep\fR\(->plugins_dir with priority TEP_PLUGIN_FIRST
        \- System\(cqs plugin directory, defined at the library compile time\&. It
          depends on the library installation prefix and usually is
          \fI(install_preffix)/lib/traceevent/plugins\fR
        \- Directory, defined by the environment variable \fITRACEEVENT_PLUGIN_DIR\fR
        \- User\(cqs plugin directory, located at \fI~/\&.local/lib/traceevent/plugins\fR
        \- Directories, specified in \fItep\fR\(->plugins_dir with priority TEP_PLUGIN_LAST
.fi
.if n \{\
.RE
.\}
.sp
Loading of plugins can be controlled by the \fItep_flags\fR, using the \fBtep_set_flag()\fR API:
.sp
.if n \{\
.RS 4
.\}
.nf
        \fITEP_DISABLE_SYS_PLUGINS\fR       \- do not load plugins, located in
                                        the system\(cqs plugin directory\&.
        \fITEP_DISABLE_PLUGINS\fR           \- do not load any plugins\&.
.fi
.if n \{\
.RE
.\}
.sp
The \fBtep_set_flag()\fR API needs to be called before \fBtep_load_plugins()\fR, if loading of all plugins is not the desired case\&.
.sp
The \fBtep_unload_plugins()\fR function unloads the plugins, previously loaded by \fBtep_load_plugins()\fR\&. The \fItep\fR argument is trace event parser context\&. The \fIplugin_list\fR is the list of loaded plugins, returned by the \fBtep_load_plugins()\fR function\&.
.sp
The \fBtep_load_plugins_hook()\fR function walks through all directories with plugins and calls user specified \fBload_plugin()\fR hook for each plugin file\&. Only files with given \fIsuffix\fR are considered to be plugins\&. The \fIdata\fR is a user specified context, passed to \fBload_plugin()\fR\&. Directories and the walk order are the same as in \fBtep_load_plugins()\fR API\&.
.sp
The \fBtep_add_plugin_path()\fR functions adds additional directories with plugins in the \fItep\fR\(->plugins_dir list\&. It must be called before \fBtep_load_plugins()\fR in order for the plugins from the new directories to be loaded\&. The \fItep\fR argument is the trace event parser context\&. The \fIpath\fR is the full path to the new plugin directory\&. The \fIprio\fR 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:
.sp
.if n \{\
.RS 4
.\}
.nf
        \fITEP_PLUGIN_FIRST\fR      \- Load plugins from this directory first
        \fITEP_PLUGIN_LAST\fR       \- Load plugins from this directory last
.fi
.if n \{\
.RE
.\}
.sp
Where the plugins in TEP_PLUGIN_LAST" will take precedence over the plugins in the other directories\&.
.sp
The \fBtep_plugin_add_option()\fR sets options defined by a plugin\&. The \fIname\fR is the name of the option to set to \fIval\fR\&. Plugins can add options to change its behavior and \fBtep_plugin_add_option()\fR is used by the application to make those modifications\&.
.SH "RETURN VALUE"
.sp
The \fBtep_load_plugins()\fR function returns a list of successfully loaded plugins, or NULL in case no plugins are loaded\&. The \fBtep_add_plugin_path()\fR function returns \-1 in case of an error, 0 otherwise\&.
.SH "EXAMPLE"
.sp
.if n \{\
.RS 4
.\}
.nf
#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\en", path, name);
}
\&.\&.\&.
tep_load_plugins_hook(tep, "\&.so", print_plugin, NULL);
\&.\&.\&.
.fi
.if n \{\
.RE
.\}
.SH "FILES"
.sp
.if n \{\
.RS 4
.\}
.nf
\fBevent\-parse\&.h\fR
        Header file to include in order to have access to the library APIs\&.
\fB\-ltraceevent\fR
        Linker switch to add when building a program that uses the library\&.
.fi
.if n \{\
.RE
.\}
.SH "SEE ALSO"
.sp
\fBlibtraceevent\fR(3), \fBtrace\-cmd\fR(1), \fBtep_set_flag\fR(3)
.SH "AUTHOR"
.sp
.if n \{\
.RS 4
.\}
.nf
\fBSteven Rostedt\fR <\m[blue]\fBrostedt@goodmis\&.org\fR\m[]\&\s-2\u[1]\d\s+2>, author of \fBlibtraceevent\fR\&.
\fBTzvetomir Stoyanov\fR <\m[blue]\fBtz\&.stoyanov@gmail\&.com\fR\m[]\&\s-2\u[2]\d\s+2>, author of this man page\&.
.fi
.if n \{\
.RE
.\}
.SH "REPORTING BUGS"
.sp
Report bugs to <\m[blue]\fBlinux\-trace\-devel@vger\&.kernel\&.org\fR\m[]\&\s-2\u[3]\d\s+2>
.SH "LICENSE"
.sp
libtraceevent is Free Software licensed under the GNU LGPL 2\&.1
.SH "RESOURCES"
.sp
\m[blue]\fBhttps://git\&.kernel\&.org/pub/scm/libs/libtrace/libtraceevent\&.git/\fR\m[]
.SH "NOTES"
.IP " 1." 4
rostedt@goodmis.org
.RS 4
\%mailto:rostedt@goodmis.org
.RE
.IP " 2." 4
tz.stoyanov@gmail.com
.RS 4
\%mailto:tz.stoyanov@gmail.com
.RE
.IP " 3." 4
linux-trace-devel@vger.kernel.org
.RS 4
\%mailto:linux-trace-devel@vger.kernel.org
.RE