setdomainname(2)

NAME

   getdomainname, setdomainname - get/set NIS domain name

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.

   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 appropriately.

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.

CONFORMING TO

   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)

COLOPHON

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