gethostname, sethostname - get or set the name of the current host
The system call returns the standard host name for the current proces‐
sor, as previously set by The namelen parameter specifies the size of
the name array. The returned name is null-terminated unless insuffi‐
cient space is provided.
The system call sets the name of the host machine to be name, which has
length namelen. This call is restricted to the superuser and is nor‐
mally used only when the system is bootstrapped.
0 If the call succeeds, it returns a value of zero.
-1 If the call fails, a value of -1 is returned and an error code is
placed in the global location, errno.
Host names are limited to 31 characters and may contain only lower case
ASCII characters a to z, numbers 0 to 9, dashes (-), underscores (_),
and periods (.).
The system call fails under the following condition:
[EFAULT] The name parameter points outside the process's allo‐
cated address space.
The system call fails under the following conditions:
[EPERM] The caller is not the superuser.
[EINVAL] The name or namelen parameter is an invalid address.
See Alsohostname(1), gethostid(2)gethostname(2)