gethostname, sethostname - get/set host name
int gethostname(char *name, size_t len);
int sethostname(const char *name, size_t len);
These functions are used to access or to change the host name of the
current processor. The gethostname() function returns a NUL-terminated
hostname (set earlier by sethostname()) in the array name that has a
length of len bytes. In case the NUL-terminated hostname does not fit,
no error is returned, but the hostname is truncated. It is unspecified
whether the truncated hostname will be NUL-terminated.
On success, zero is returned. On error, -1 is returned, and errno is
EINVAL len is negative or, for sethostname, len is larger than the max-
imum allowed size, or, for gethostname on Linux/i386, len is
smaller than the actual size. (In this last case glibc 2.1 uses
EPERM For sethostname, the caller was not the superuser.
EFAULT name is an invalid address.
SVr4, 4.4BSD (this function first appeared in 4.2BSD). POSIX
1003.1-2001 specifies gethostname but not sethostname.
For many Linux kernel / libc combinations gethostname will return an
error instead of returning a truncated hostname.
SUSv2 guarantees that `Host names are limited to 255 bytes'. POSIX
1003.1-2001 guarantees that `Host names (not including the terminating
NUL) are limited to HOST_NAME_MAX bytes'.
getdomainname(2), setdomainname(2), uname(2)
Linux 2.5.0 2001-12-15 gethostname(2)