gethostname(2)
Name
gethostname, sethostname − get or set the name of the current host
Syntax
gethostname(name, namelen)
char *name;
int namelen; sethostname(name, namelen)
char *name;
int namelen;
Description
The gethostname system call returns the standard host name for the current processor, as previously set by sethostname. The namelen parameter specifies the size of the name array. The returned name is null-terminated unless insufficient space is provided.
The sethostname 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 normally used only when the system is bootstrapped.
Return Value
0If the call succeeds, it returns a value of zero.
−1If the call fails, a value of −1 is returned and an error code is placed in the global location, errno.
Restrictions
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 (.).
Diagnostics
The gethostname system call fails under the following condition:
[EFAULT]The name parameter points outside the process’s allocated address space.
The sethostname system call fails under the following conditions:
[EPERM]The caller is not the superuser.
[EINVAL]The name or namelen parameter is an invalid address.