getegid(2)

getegid2

Get group process identification

Part of getgid(2).

Usage

#include <unistd.h>

gid_t

getgid(void);

gid_t

getegid(void);

Library

Standard C Library (libc, -lc)

Overview

The getgid() system call returns the real group ID of the calling process, getegid() returns the effective group ID of the calling process.

The real group ID is specified at login time.

The real group ID is the group of the user who invoked the program. As the effective group ID gives the process additional permissions during the execution of “set-group-ID” mode processes, getgid() is used to determine the real-user-id of the calling process.

Errors

The getgid() and getegid() system calls are always successful, and no return value is reserved to indicate an error.

Releases

87 releases since FreeBSD 2.0.5-RELEASE; the text changed 43 times.

  1. 2.0.5
  2. 2.1.5–2.1.7.1
  3. 2.2.2–2.2.5
  4. 2.2.6–3.4
  5. 3.5–3.5.1
  6. 4.0
  7. 4.1–4.3
  8. 4.4
  9. 4.5–4.11
  10. 5.0
  11. 5.1–6.3
  12. 6.4
  13. 7.0
  14. 7.1
  15. 7.2
  16. 7.3
  17. 7.4
  18. 8.0
  19. 8.1
  20. 8.2
  21. 8.3
  22. 8.4
  23. 9.0
  24. 9.1
  25. 9.2
  26. 9.3
  27. 10.0
  28. 10.1
  29. 10.2
  30. 10.3
  31. 10.4
  32. 11.0
  33. 11.1
  34. 11.2
  35. 11.3
  36. 11.4
  37. 12.0
  38. 12.1
  39. 12.2
  40. 12.3
  41. 12.4
  42. 13.0–13.2
  43. 13.3–14.5
  44. 15.0–16.0

Standards

The getgid() and getegid() system calls are expected to conform to ISO/IEC 9945-1:1990 (“POSIX.1”).

History

The getgid() function appeared in Version 4 AT&T UNIX.

From base 16.0-CURRENT-20261027-61c70dc16a79 in FreeBSD 16.0-CURRENT (2026-10-27). Parsed by carta from the page's mdoc source.