NAME

       getdomainname, setdomainname - get/set NIS domain name

LIBRARY

       Standard C library (libc, -lc)

SYNOPSIS

       #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)

DESCRIPTION

       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).

RETURN VALUE

       On  success, zero is returned.  On error, -1 is returned, and errno is set to indicate the
       error.

ERRORS

       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.

STANDARDS

       POSIX does not specify these calls.

NOTES

       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).

SEE ALSO

       gethostname(2), sethostname(2), uname(2), uts_namespaces(7)