---
name: "utmpx.h"
section: "0p"
platform: "linux"
package: "man-pages"
version: "6.19-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/utmpx.h"
---

# utmpx.h(0p)

user accounting database definitions

## PROLOG

This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.

## NAME

utmpx.h — user accounting database definitions

## SYNOPSIS

```
#include <utmpx.h>
```

## DESCRIPTION

The *\<utmpx.h\>* header shall define the **utmpx** structure that shall include at least the following members:

```
char            ut_user[]  User login name.
char            ut_id[]    Unspecified initialization process identifier.
char            ut_line[]  Device name.
pid_t           ut_pid     Process ID.
short           ut_type    Type of entry.
struct timeval  ut_tv      Time entry was made.
```

The *\<utmpx.h\>* header shall define the **pid\_t** type through **typedef**, as described in *\<sys/types.h\>*.

The *\<utmpx.h\>* header shall define the **timeval** structure as described in *\<sys/time.h\>*.

Inclusion of the *\<utmpx.h\>* header may also make visible all symbols from *\<sys/time.h\>*.

The *\<utmpx.h\>* header shall define the following symbolic constants as possible values for the *ut\_type* member of the **utmpx** structure:

- EMPTY

  No valid user accounting information.

- BOOT\_TIME

  Identifies time of system boot.

- OLD\_TIME

  Identifies time when system clock changed.

- NEW\_TIME

  Identifies time after system clock changed.

- USER\_PROCESS

  Identifies a process.

- INIT\_PROCESS

  Identifies a process spawned by the init process.

- LOGIN\_PROCESS

  Identifies the session leader of a logged-in user.

- DEAD\_PROCESS

  Identifies a session leader who has exited.

The following shall be declared as functions and may also be defined as macros. Function prototypes shall be provided.

```
void          endutxent(void);
struct utmpx *getutxent(void);
struct utmpx *getutxid(const struct utmpx *);
struct utmpx *getutxline(const struct utmpx *);
struct utmpx *pututxline(const struct utmpx *);
void          setutxent(void);
```

*The following sections are informative.*

## APPLICATION USAGE

None.

## RATIONALE

None.

## FUTURE DIRECTIONS

None.

## SEE ALSO

***\<sys\_time.h\>***, ***\<sys\_types.h\>***

The System Interfaces volume of POSIX.1‐2017, *endutxent()*

## COPYRIGHT

Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .

Any typographical or formatting errors that appear in this page are most likely to have been introduced during the conversion of the source files to man page format. To report such errors, see https://www.kernel.org/doc/man-pages/reporting\_bugs.html .