---
name: "profil"
section: "3"
platform: "linux"
package: "man-pages"
version: "6.19-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/profil/3"
---

# profil(3)

execution time profile

## NAME

profil - execution time profile

## LIBRARY

Standard C library (*libc*, *-lc*)

## SYNOPSIS

```
#include <unistd.h>
```

**int profil(unsigned short \****buf***, size\_t** *bufsiz***,**            **size\_t** *offset***, unsigned int** *scale***);**

Feature Test Macro Requirements for glibc (see [**feature\_test\_macros**(7)](/feature_test_macros/7.md)):

**profil**():

```
    Since glibc 2.21:
        _DEFAULT_SOURCE
    In glibc 2.19 and 2.20:
        _DEFAULT_SOURCE || (_XOPEN_SOURCE && _XOPEN_SOURCE < 500)
    Up to and including glibc 2.19:
        _BSD_SOURCE || (_XOPEN_SOURCE && _XOPEN_SOURCE < 500)
```

## DESCRIPTION

This routine provides a means to find out in what areas your program spends most of its time. The argument *buf* points to *bufsiz* bytes of core. Every virtual 10 milliseconds, the user's program counter (PC) is examined: *offset* is subtracted and the result is multiplied by *scale* and divided by 65536. If the resulting value is less than *bufsiz*, then the corresponding entry in *buf* is incremented. If *buf* is NULL, profiling is disabled.

## RETURN VALUE

Zero is always returned.

## ATTRIBUTES

For an explanation of the terms used in this section, see [**attributes**(7)](/attributes/7.md).

| | | |
| --- | --- | --- |
| **Interface** | **Attribute** | **Value** |
| **profil**() | Thread safety | MT-Unsafe |

## STANDARDS

None.

## HISTORY

Similar to a call in SVr4.

## BUGS

**profil**() cannot be used on a program that also uses **ITIMER\_PROF** interval timers (see [**setitimer**(2)](/setitimer/2.md)).

True kernel profiling provides more accurate results.

## SEE ALSO

[**gprof**(1)](/gprof/1.md), [**sprof**(1)](/sprof/1.md), [**setitimer**(2)](/setitimer/2.md), [**sigaction**(2)](/sigaction/2.md), [**signal**(2)](/signal/2.md)