NAME
gethostname,
sethostname —
get/set name of current host
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include
<unistd.h>
int
gethostname(char
*name, size_t
namelen);
int
sethostname(const
char *name, int
namelen);
DESCRIPTION
The
gethostname()
function returns the standard host name for the current processor, as
previously set by sethostname(). The
namelen argument specifies the size of the
name array. The returned name is null-terminated,
unless insufficient space is provided.
The
sethostname()
function sets the name of the host machine to be name,
which has length namelen. This call is restricted to
the super-user and is normally used only when the system is
bootstrapped.
Host names are limited in length to
{sysconf(_SC_HOST_NAME_MAX)} characters, not
including the trailing null, currently 255.
RETURN VALUES
Upon successful completion, the value 0 is returned; otherwise the value -1 is returned and the global variable errno is set to indicate the error.
ERRORS
The following errors may be returned by these calls:
- [
EFAULT] - The name or namelen argument gave an invalid address.
- [
ENAMETOOLONG] - The current host name is longer than namelen. (For
gethostname() only.) - [
EPERM] - The caller tried to set the host name and was not the super-user.
SEE ALSO
STANDARDS
The gethostname() function conforms to
IEEE Std 1003.1-2001 (“POSIX.1”).
Callers should be aware that
{sysconf(_SC_HOST_NAME_MAX)} may be variable or
infinite, but is guaranteed to be no less than
{_POSIX_HOST_NAME_MAX}. On older systems, this limit
was defined in the non-standard header
<sys/param.h> as
MAXHOSTNAMELEN, and counted the terminating null.
The sethostname() function and the error returns for
gethostname() are not standardized.
HISTORY
The gethostname() function appeared in
4.2BSD. The namelen argument
to gethostname() was changed to
size_t in FreeBSD 5.2 for
alignment with IEEE Std 1003.1-2001
(“POSIX.1”).