getdomainname, setdomainname - get/set NIS domain name
#include <unistd.h>
int getdomainname(char *name, size_t len);
int setdomainname(const char *name, size_t
len);
Feature Test Macro Requirements for glibc (see
feature_test_macros(7)):
getdomainname(),
setdomainname():
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)
These functions are used to access or to change the NIS domain name of the host
system. More precisely, they operate on the NIS domain name associated with
the calling process's UTS namespace.
setdomainname() sets the domain name to the value given in the character
array
name. The
len argument specifies the number of bytes in
name. (Thus,
name does not require a terminating null byte.)
getdomainname() returns the null-terminated domain name in the character
array
name, which has a length of
len bytes. If the
null-terminated domain name requires more than
len bytes,
getdomainname() returns the first
len bytes (glibc) or gives an
error (libc).
On success, zero is returned. On error, -1 is returned, and
errno is set
appropriately.
setdomainname() can fail with the following errors:
- EFAULT
- name pointed outside of user address space.
- EINVAL
- len was negative or too large.
- EPERM
- The caller did not have the CAP_SYS_ADMIN capability in the user
namespace associated with its UTS namespace (see
namespaces(7)).
getdomainname() can fail with the following errors:
- EINVAL
- For getdomainname() under libc: name is NULL or name
is longer than len bytes.
POSIX does not specify these calls.
Since Linux 1.0, the limit on the length of a domain name, including the
terminating null byte, is 64 bytes. In older kernels, it was 8 bytes.
On most Linux architectures (including x86), there is no
getdomainname()
system call; instead, glibc implements
getdomainname() as a library
function that returns a copy of the
domainname field returned from a
call to
uname(2).
gethostname(2),
sethostname(2),
uname(2),
uts_namespaces(7)