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

# getgrent(3)

get group file entry

## NAME

getgrent, setgrent, endgrent - get group file entry

## LIBRARY

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

## SYNOPSIS

```
#include <sys/types.h>
#include <grp.h>
```

**struct group \*getgrent(void);**

**void setgrent(void);** **void endgrent(void);**

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

**setgrent**():

```
    _XOPEN_SOURCE >= 500
        || /* glibc >= 2.19: */ _DEFAULT_SOURCE
        || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
```

**getgrent**(), **endgrent**():

```
    Since glibc 2.22:
        _XOPEN_SOURCE >= 500 || _DEFAULT_SOURCE
    glibc 2.21 and earlier
        _XOPEN_SOURCE >= 500
            || /* Since glibc 2.12: */ _POSIX_C_SOURCE >= 200809L
            || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
```

## DESCRIPTION

The **getgrent**() function returns a pointer to a structure containing the broken-out fields of a record in the group database (e.g., the local group file */etc/group*, NIS, and LDAP). The first time **getgrent**() is called, it returns the first entry; thereafter, it returns successive entries.

The **setgrent**() function rewinds to the beginning of the group database, to allow repeated scans.

The **endgrent**() function is used to close the group database after all processing has been performed.

The *group* structure is defined in *\<grp.h\>* as follows:

```
struct group {
    char   *gr_name;        /* group name */
    char   *gr_passwd;      /* group password */
    gid_t   gr_gid;         /* group ID */
    char  **gr_mem;         /* NULL-terminated array of pointers
                               to names of group members */
};
```

For more information about the fields of this structure, see [**group**(5)](/group/5.md).

## RETURN VALUE

The **getgrent**() function returns a pointer to a *group* structure, or NULL if there are no more entries or an error occurs.

Upon error, *errno* may be set. If one wants to check *errno* after the call, it should be set to zero before the call.

The return value may point to a static area, and may be overwritten by subsequent calls to **getgrent**(), [**getgrgid**(3)](/getgrgid/3.md), or [**getgrnam**(3)](/getgrnam/3.md). (Do not pass the returned pointer to [**free**(3)](/free/3.md).)

## ERRORS

- **EAGAIN**

  The service was temporarily unavailable; try again later. For NSS backends in glibc this indicates a temporary error talking to the backend. The error may correct itself; retrying later is suggested.

- **EINTR**

  A signal was caught; see [**signal**(7)](/signal/7.md).

- **EIO**

  I/O error.

- **EMFILE**

  The per-process limit on the number of open file descriptors has been reached.

- **ENFILE**

  The system-wide limit on the total number of open files has been reached.

- **ENOENT**

  A necessary input file cannot be found. For NSS backends in glibc this indicates the backend is not correctly configured.

- **ENOMEM**

  Insufficient memory to allocate *group* structure.

- **ERANGE**

  Insufficient buffer space supplied.

## FILES

- */etc/group*

  local group database file

## ATTRIBUTES

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

| | | |
| --- | --- | --- |
| **Interface** | **Attribute** | **Value** |
| **getgrent**() | Thread safety | MT-Unsafe race:grent race:grentbuf locale |
| **setgrent**(), **endgrent**() | Thread safety | MT-Unsafe race:grent locale |

In the above table, *grent* in *race:grent* signifies that if any of the functions **setgrent**(), **getgrent**(), or **endgrent**() are used in parallel in different threads of a program, then data races could occur.

## STANDARDS

POSIX.1-2008.

## HISTORY

POSIX.1-2001, SVr4, 4.3BSD.

## SEE ALSO

[**fgetgrent**(3)](/fgetgrent/3.md), [**getgrent\_r**(3)](/getgrent_r/3.md), [**getgrgid**(3)](/getgrgid/3.md), [**getgrnam**(3)](/getgrnam/3.md), [**getgrouplist**(3)](/getgrouplist/3.md), [**putgrent**(3)](/putgrent/3.md), [**group**(5)](/group/5.md)