---
name: "tep_read_number_field"
section: "3"
platform: "linux"
package: "libtraceevent"
version: "1:1.9.1-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/tep_read_number_field"
---

# tep\_read\_number\_field(3)

Reads a number from raw data.

## NAME

tep\_read\_number\_field - Reads a number from raw data.

## SYNOPSIS

```
#include <event-parse.h>
int tep_read_number_field(struct tep_format_field *field, const void *data, unsigned long long *value);
```

## DESCRIPTION

The **tep\_read\_number\_field()** function reads the value of the *field* from the raw *data* and stores it in the *value*. The function sets the *value* according to the endianness of the raw data and the current machine and stores it in *value*.

## RETURN VALUE

The **tep\_read\_number\_field()** function retunrs 0 in case of success, or -1 in case of an error.

## EXAMPLE

```
#include <event-parse.h>
...
struct tep_handle *tep = tep_alloc();
...
struct tep_event *event = tep_find_event_by_name(tep, "timer", "hrtimer_start");
...
void process_record(struct tep_record *record)
{
        unsigned long long pid;
        struct tep_format_field *field_pid = tep_find_common_field(event, "common_pid");
        if (tep_read_number_field(field_pid, record->data, &pid) != 0) {
                /* Failed to get "common_pid" value */
        }
}
...
```

## FILES

```
event-parse.h
        Header file to include in order to have access to the library APIs.
-ltraceevent
        Linker switch to add when building a program that uses the library.
```

## SEE ALSO

[**libtraceevent**(3)](/libtraceevent/3.md), [**trace-cmd**(1)](/trace-cmd/1.md)

## AUTHOR

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

## REPORTING BUGS

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

## LICENSE

libtraceevent is Free Software licensed under the GNU LGPL 2.1

## RESOURCES

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

## 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