'\" t
.\"     Title: libtracefs
.\"    Author: [see the "AUTHOR" section]
.\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>
.\"      Date: 01/15/2021
.\"    Manual: libtracefs Manual
.\"    Source: libtracefs 1.0.2
.\"  Language: English
.\"
.TH "LIBTRACEFS" "3" "01/15/2021" "libtracefs 1\&.0\&.2" "libtracefs Manual"
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.SH "NAME"
tracefs_tracers, tracefs_get_clock, tracefs_list_free \- Helper functions for working with trace file system\&.
.SH "SYNOPSIS"
.sp
.nf
\fB#include <tracefs\&.h>\fR

char **\fBtracefs_tracers\fR(const char *\fItracing_dir\fR);
char *\fBtracefs_get_clock\fR(struct tracefs_instance *\fIinstance\fR);
void \fBtracefs_list_free\fR(char **\fIlist\fR);
.fi
.SH "DESCRIPTION"
.sp
Various useful functions for working with trace file system\&.
.sp
The \fItracefs_tracers()\fR function returns array of strings with the names of supported tracer plugins, located in the given \fItracing_dir\fR directory\&. This could be NULL or the location of the tracefs mount point for the trace systems of the local machine, or it may be a path to a copy of the tracefs directory from another machine\&. The last entry in the array as a NULL pointer\&. The array must be freed with \fItracefs_list_free()\fR API\&.
.sp
The \fItracefs_get_clock()\fR function returns name of the current trace clock, used in the given \fIinstance\fR\&. If \fIinstance\fR is NULL, the clock of the main trace instance is returned\&. The returned string must be freed with free()\&.
.sp
The \fItracefs_list_free()\fR function frees an array of strings, returned by \fItracefs_event_systems()\fR, \fItracefs_system_events()\fR and \fItracefs_tracers()\fR APIs\&.
.SH "RETURN VALUE"
.sp
The \fItracefs_tracers()\fR returns array of strings\&. The last element in that array is a NULL pointer\&. The array must be freed with \fItracefs_list_free()\fR API\&. In case of an error, NULL is returned\&.
.sp
The \fItracefs_get_clock()\fR returns string, that must be freed with free(), or NULL in case of an error\&.
.SH "EXAMPLE"
.sp
.if n \{\
.RS 4
.\}
.nf
#include <tracefs\&.h>

char **tracers = tracefs_tracers(NULL);

        if (tracers) {
                /* Got tracer plugins from the top trace instance */
                \&.\&.\&.
                tracefs_list_free(tracers);
        }
\&.\&.\&.\&.
char *clock = tracefs_get_clock(NULL);

        if (clock) {
                /* Got current trace clock of the top trace instance */
                \&.\&.\&.
                free(clock);
        }
.fi
.if n \{\
.RE
.\}
.SH "FILES"
.sp
.if n \{\
.RS 4
.\}
.nf
\fBtracefs\&.h\fR
        Header file to include in order to have access to the library APIs\&.
\fB\-ltracefs\fR
        Linker switch to add when building a program that uses the library\&.
.fi
.if n \{\
.RE
.\}
.SH "SEE ALSO"
.sp
\fIlibtracefs(3)\fR, \fIlibtraceevent(3)\fR, \fItrace\-cmd(1)\fR
.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>
\fBTzvetomir Stoyanov\fR <\m[blue]\fBtz\&.stoyanov@gmail\&.com\fR\m[]\&\s-2\u[2]\d\s+2>
.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
libtracefs is Free Software licensed under the GNU LGPL 2\&.1
.SH "RESOURCES"
.sp
\m[blue]\fBhttps://git\&.kernel\&.org/pub/scm/libs/libtrace/libtracefs\&.git/\fR\m[]
.SH "COPYING"
.sp
Copyright (C) 2020 VMware, Inc\&. Free use of this software is granted under the terms of the GNU Public License (GPL)\&.
.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