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LIBTRACECMD(3) libtracefs Manual LIBTRACECMD(3)

NAME

libtracecmd - trace-cmd library APIs

SYNOPSIS

#include <trace-cmd.h>
Open and close trace file:

struct tracecmd_input *tracecmd_open(const char *file, int flags);
struct tracecmd_input *tracecmd_open_fd(int fd, int flags);
struct tracecmd_input *tracecmd_open_head(const char *file, int flags);
void tracecmd_close(struct tracecmd_input *handle);
void tracecmd_set_private(struct tracecmd_input *handle, void *data);
void *tracecmd_get_private(struct tracecmd_input *handle); Read tracing records from a trace file:
int tracecmd_init_data(struct tracecmd_input *handle);
struct tep_record *tracecmd_read_cpu_first(struct tracecmd_input *handle, int cpu);
struct tep_record *tracecmd_read_data(struct tracecmd_input *handle, int cpu);
struct tep_record *tracecmd_read_at(struct tracecmd_input *handle, unsigned long long offset, int *cpu);
void tracecmd_free_record(struct tep_record *record);
struct tep_handle *tracecmd_get_tep(struct tracecmd_input *handle); Iterating over events in a trace file:
int tracecmd_iterate_events(struct tracecmd_input *handle,
cpu_set_t *cpus, int cpu_size,
int (*callback)(struct tracecmd_input *,
struct tep_record *,
int, void *),
void *callback_data);
int tracecmd_iterate_events_multi(struct tracecmd_input **handles,
int nr_handles,
int (*callback)(struct tracecmd_input *,
struct tep_record *,
int, void *),
void *callback_data);
int tracecmd_follow_event(struct tracecmd_input *handle,
const char *system, const char *event_name,
int (*callback)(struct tracecmd_input *,
struct tep_event *,
struct tep_record *,
int, void *),
void *callback_data);
int tracecmd_follow_missed_events(struct tracecmd_input *handle,
int (*callback)(struct tracecmd_input *,
struct tep_event *,
struct tep_record *,
int, void *),
void *callback_data);
struct tracecmd_filter *tracecmd_filter_add(struct tracecmd_input handle,
const char *filter_str, bool neg); Read tracing instances from a trace file:
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); Handle time stamps from a trace file:
unsigned long long tracecmd_get_first_ts(struct tracecmd_input *handle);
void tracecmd_add_ts_offset(struct tracecmd_input *handle, long long offset); Get traceing peer information from a trace file:
unsigned long long tracecmd_get_traceid(struct tracecmd_input *handle);
int tracecmd_get_guest_cpumap(struct tracecmd_input *handle, unsigned long long trace_id, const char **name, int *vcpu_count, const int **cpu_pid); Mapping host and guest trace files:
int tracecmd_map_vcpus(struct tracecmd_input **handles, int nr_handles);
struct tracecmd_cpu_map *tracecmd_get_cpu_map(struct tracecmd_input *handle, int cpu);
struct tracecmd_cpu_map *tracecmd_map_find_by_host_pid(struct tracecmd_input *handle,
int host_pid);
int tracecmd_map_get_host_pid(struct tracecmd_cpu_map *map);
struct tracecmd_input *tracecmd_map_get_guest(struct tracecmd_cpu_map *map);
void tracecmd_map_set_private(struct tracecmd_cpu_map *map, void *priv);
void *tracecmd_map_get_private(struct tracecmd_cpu_map *map); Control library logs:
int tracecmd_set_loglevel(enum tep_loglevel level);

DESCRIPTION

The libtracecmd(3) library provides APIs to read, parse and write trace-cmd.dat(5) files, recorded with trace-cmd(1) application and containing tracing information from ftrace, the official Linux kernel tracer.

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

libtraceevent(3) libtracefs(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
01/22/2023 libtracefs