Man page - tracecmd_buffer_instance_handle(3)

Packages contains this manual

Package:  trace-cmd
apt-get install trace-cmd

Manuals in package:
• tracecmd_follow_missed_events(3)
• trace-cmd-mem(1)
• trace-cmd(1)
• trace-cmd-hist(1)
• tracecmd_map_get_guest(3)
• trace-cmd-sqlhist(1)
• tracecmd_read_cpu_first(3)
• trace-cmd-convert(1)
• tracecmd_iterate_events(3)
• trace-cmd-check-events(1)
• trace-cmd-start(1)
• tracecmd_map_set_private(3)
• tracecmd_get_tsc2nsec(3)
• tracecmd_read_at(3)
• tracecmd_filter_add(3)
• trace-cmd-report(1)
• tracecmd_get_cpu_map(3)
• trace-cmd-profile(1)
• trace-cmd-set(1)
• trace-cmd-show(1)
• trace-cmd-dump(1)
• trace-cmd-snapshot(1)
• tracecmd_map_get_private(3)
• trace-cmd-stream(1)
• trace-cmd-clear(1)
• tracecmd_iterate_reset(3)
• trace-cmd-listen(1)
• tracecmd_iterate_events_multi(3)
• trace-cmd-list(1)
• tracecmd_open_fd(3)
• tracecmd_add_ts_offset(3)
• tracecmd_buffer_instance_name(3)
• tracecmd_get_private(3)
• tracecmd_map_get_host_pid(3)
• tracecmd_set_private(3)
• trace-cmd-options(1)
• tracecmd_buffer_instances(3)
• tracecmd_read_data(3)
• trace-cmd-attach(1)
• tracecmd_free_record(3)
• tracecmd_set_loglevel(3)
• tracecmd_get_first_ts(3)
• tracecmd_init_data(3)
• trace-cmd-stat(1)
• tracecmd_get_traceid(3)
• tracecmd_close(3)
• tracecmd_follow_event(3)
• trace-cmd-reset(1)
• tracecmd_open_head(3)
• tracecmd_map_find_by_host_pid(3)
• trace-cmd.dat.v7(5)
• trace-cmd-stack(1)
• trace-cmd-agent(1)
• tracecmd_map_vcpus(3)
• tracecmd_get_guest_cpumap(3)
• libtracecmd(3)
• trace-cmd-stop(1)
• trace-cmd.dat.v6(5)
• tracecmd_get_tep(3)
• trace-cmd-restore(1)
• trace-cmd-extract(1)
• tracecmd_buffer_instance_handle(3)
• trace-cmd-record(1)
• tracecmd_open(3)
• trace-cmd-split(1)
Documentations in package:
• trace-cmd

Manual

LIBTRACECMD

NAME
SYNOPSIS
DESCRIPTION
RETURN VALUE
EXAMPLE
FILES
SEE ALSO
AUTHOR
REPORTING BUGS
LICENSE
RESOURCES
COPYING
NOTES

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NAME

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

SYNOPSIS

#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 );

DESCRIPTION

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() .

RETURN VALUE

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)

EXAMPLE

#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);

FILES

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.

SEE ALSO

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

AUTHOR

Steven Rostedt < rostedt@goodmis.org [1] >
Tzvetomir Stoyanov < tz.stoyanov@gmail.com [2] >

REPORTING BUGS

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

LICENSE

libtracecmd is Free Software licensed under the GNU LGPL 2.1

RESOURCES

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

COPYING

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

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

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