getdomainname(2) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | CONFORMING TO | NOTES | SEE ALSO | COLOPHON

GETDOMAINNAME(2)        Linux Programmer's Manual       GETDOMAINNAME(2)

NAME         top

       getdomainname, setdomainname - get/set NIS domain name

SYNOPSIS         top

       #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         top

       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         top

       On success, zero is returned.  On error, -1 is returned, and
       errno is set appropriately.

ERRORS         top

       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.

CONFORMING TO         top

       POSIX does not specify these calls.

NOTES         top

       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         top

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

COLOPHON         top

       This page is part of release 5.10 of the Linux man-pages project.
       A description of the project, information about reporting bugs,
       and the latest version of this page, can be found at
       https://www.kernel.org/doc/man-pages/.

Linux                          2019-10-10               GETDOMAINNAME(2)

Pages that refer to this page: hostname(1)gethostname(2)syscalls(2)uname(2)capabilities(7)uts_namespaces(7)