tracecmd_buffer_instances, tracecmd_buffer_instance_name, tracecmd_buffer_instance_handle - Read tracing

StevenRostedt <rostedt@goodmis.org[1]>
           TzvetomirStoyanov <tz.stoyanov@gmail.com[2]>

       Copyright (C) 2020 VMware, Inc. Free use of this software is granted under the terms of the GNU Public
       License (GPL).

       This set of APIs can be used to get information and read tracing data from tracing instances stored in a
       trace file.

       The tracecmd_buffer_instances() function gets the number of tracing instances recorded in a trace file.
       The top instance is not counted. The handle is a tracecmd_input handler returned by tracecmd_open_head().

       The tracecmd_buffer_instance_name() function gets the name of the tracing instance with given index indx,
       recorded in a trace file. The indx is a number in the interval [0 .. count-1], where count is the number
       returned by tracecmd_buffer_instances(). The handle is a tracecmd_input handler returned by
       tracecmd_open_head().

       The tracecmd_buffer_instance_handle() allocates and initializes a tracecmd_input handle, associated with
       trace instance with index indx from a trace file. The handle is a tracecmd_input handler returned by
       tracecmd_open_head(). The indx is a number in the interval [0 .. count-1], where count is the number
       returned by tracecmd_buffer_instances().

           #include <trace-cmd.h>
           ...
           struct tracecmd_input *handle = tracecmd_open_head("trace.dat");
                   if (!handle) {
                           /* Failed to open trace.dat file */
                   }
           ...
           int num = tracecmd_buffer_instances(handle);

                   while(num) {
                           struct tracecmd_input *h;
                           char *name;

                           name = tracecmd_buffer_instance_name(handle, num);
                           if (!name) {
                                   /* Failed to get name of instance num */
                           }
                           h = tracecmd_buffer_instance_handle(handle, num);
                           if (!h) {
                                   /* Failed to initialize handler for instance num */
                           }

                           ...
                           tracecmd_close(h);
                           num--;
                   }
           ...
                   tracecmd_close(handle);

trace-cmd.h
                   Header file to include in order to have access to the library APIs.
           -ltracecmd
                   Linker switch to add when building a program that uses the library.

       libtracecmd is Free Software licensed under the GNU LGPL 2.1

       tracecmd_buffer_instances, tracecmd_buffer_instance_name, tracecmd_buffer_instance_handle - Read tracing
       instances from a trace file.

        1. rostedt@goodmis.orgmailto:rostedt@goodmis.org

        2. tz.stoyanov@gmail.commailto:tz.stoyanov@gmail.com

        3. linux-trace-devel@vger.kernel.orgmailto:linux-trace-devel@vger.kernel.org

libtracefs                                         06/23/2025                                     LIBTRACECMD(3)

       Report bugs to <linux-trace-devel@vger.kernel.org[3]>

https://git.kernel.org/pub/scm/utils/trace-cmd/trace-cmd.git/

       The tracecmd_buffer_instances() function returns the number of tracing instances recorded in a trace
       file.

       The tracecmd_buffer_instance_name() function returns a string, the name of a tracing instance, or NULL in
       case of an error The string must not be freed.

       The tracecmd_buffer_instance_handle() function returns a pointer to newly allocated tracecmd_input
       handler or NULL in case if an error. The returned handler must be closed by tracecmd_close()(3)

libtracefs(3), libtraceevent(3), trace-cmd(1)trace-cmd.dat(5)

#include<trace-cmd.h>

       int tracecmd_buffer_instances(struct tracecmd_input *handle);
       const char *tracecmd_buffer_instance_name(struct tracecmd_input *handle, int indx);
       struct tracecmd_input *tracecmd_buffer_instance_handle(struct tracecmd_input *handle, int indx);