LIBTRACEEVENT(3)

💖 LIBTRACEEVENT(3) — the libtraceevent manual, bestie edition 💖

okay so real talk: this is page 3 of the libtraceevent Manual, and it's about two lil functions that read event formats. they're lowkey the glow-up your tracing setup needs. let's go 🦋

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✨ NAME ✨

tep_parse_event, tep_parse_format — parse the event format information, babes. that's the whole job. parsing. formats. events. slay 💅

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🌸 SYNOPSIS 🌸

#include <event-parse.h>

enum tep_errno tep_parse_event(struct tep_handle *tep, const char *buf, unsigned long size, const char *sys);
enum tep_errno tep_parse_format(struct tep_handle *tep, struct tep_event **eventp, const char *buf, unsigned long size, const char *sys);

like. look at those signatures. iconic. copy them exactly, no cap, do not freestyle 🎀

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🫶 DESCRIPTION 🫶

so tep_parse_event() parses the event format and, in doing so, creates an event structure — a whole little parser buddy that can then quickly parse raw data for a given event. it's giving build-a-bear but for tracing data 💀

breaking down the args, because we don't gatekeep:

• tep — the trace event parser context.
• buf — a buffer, of length size, where the event format data lives.
• size — the size of that buffer. yes, the one right above. they're a duo.
• sys — the system of the event.

the created event structure is stored in the tep context. and where does that event format data actually come from? tracefs/events/.../.../format files, bestie. that's the source. 🌈

now tep_parse_format() — it does the same thing as tep_parse_event(). literally the same. the only difference is that extra eventp argument, which is where the newly created event structure gets returned to you. that's it. that's the whole diff. ✨

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👑 RETURN VALUE 👑

both tep_parse_event() and tep_parse_format() return 0 on success, or TEP_ERRNO__... in case of an error. so like, check your returns. zero good, error code not zero. vibe check accordingly ⭐

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🔥 EXAMPLE 🔥

here's the whole thing, verbatim, don't touch it:

#include <event-parse.h>
...
struct tep_handle *tep = tep_alloc();
...
char *buf;
int size;
struct tep_event *event = NULL;
buf = read_file("/sys/kernel/tracing/events/ftrace/print/format", &size);
if (tep_parse_event(tep, buf, size, "ftrace") != 0) {
        /* Failed to parse the ftrace print format */
}

if (tep_parse_format(tep, &event, buf, size, "ftrace") != 0) {
        /* Failed to parse the ftrace print format */
}
...

see how they both get called on the exact same buffer? yeah. same data, two doors. ate 💖

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🎀 FILES 🎀

• event-parse.h — the header file you include to get access to the library APIs. include it or perish (not really, but like, you won't have the functions).
• -ltraceevent — the linker switch you add when building a program that uses the library. put it in your build and let it cook 🔥

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🌟 SEE ALSO 🌟

libtraceevent(3), trace-cmd(1)

go read those too, they're part of the cinematic universe 🫶

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💜 AUTHOR 💜

• Steven Rostedt <rostedt@goodmis.org[1]>, author of libtraceevent. 👑
• Tzvetomir Stoyanov <tz.stoyanov@gmail.com[2]>, author of this man page. 🎀

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🐛 REPORTING BUGS 🐛

found a bug? don't sit on it, bestie. report bugs to <linux-trace-devel@vger.kernel.org[3]> 💌

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📜 LICENSE 📜

libtraceevent is Free Software licensed under the GNU LGPL 2.1. periodt.

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🌈 RESOURCES 🌈

https://git.kernel.org/pub/scm/libs/libtrace/libtraceevent.git/

that's the repo. go be nosy, it's encouraged 🧚

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📝 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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ok that's the whole page, every flag, every arg, every email, every note. nothing skipped, nothing invented. i would never do that to you 💅

and that's a wrap on libtraceevent 1.9.0, dated 06/15/2026 — thanks for reading to the very end bestie, you're the main character of this man page now 🦋💖✨