getegid(2)                                                   getegid(2)

  getgid()

  NAME

    getgid(), getegid() - get group process identification

  SYNOPSIS

    #include 

    gid_t getgid (void)
    gid_t getegid (void)

  DESCRIPTION

    The getgid(2) function returns the real group ID of the calling process,
    getegid(2) returns the effective group ID of the calling process.

    The real group ID is the group of the user who invoked the program. The
    real group ID is specified at login time.

    The effective group ID is the group of the process, if it has the set-
    group-ID mode set. Since the effective group ID gives the process
    additional permissions during execution, getgid(2) is used to determine
    the real-user-id of the calling process.

  ERRORS

    The getgid(2) and getegid(2) functions are always successful, and no
    return value is reserved to indicate an error.

  SEE ALSO

    getuid(2)

    setgid(2)

  USAGE NOTES

    All of these functions are thread safe.

    All of these functions are async-signal safe.