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.  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 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), uts_namespaces(7)

COLOPHON

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