gethostname(3)

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 to {HOST_NAME_MAX} characters, not

including the
trailing null, currently 255.

RETURN VALUES

The function returns the value 0 if successful; 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 in

valid 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

sysconf(3), sysctl(3)

STANDARDS

The gethostname() function conforms to . Callers should be

aware that
{HOST_NAME_MAX} may be variable or infinite, but is guaran

teed to be no
less than {_POSIX_HOST_NAME_MAX}. On older systems, this

limit was
defined in the non-standard header #include <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 .

BSD August 18, 2003

BSD