These system calls are used to access or to change the hostname of the
current processor.
The
gethostname()
system call returns a null-terminated hostname (set earlier by
sethostname())
in the array name that has a length of len bytes.
In case the null-terminated hostname does not fit, no error is
returned, but the hostname is truncated.
It is unspecified
whether the truncated hostname will be null-terminated.
RETURN VALUE
On success, zero is returned.
On error, -1 is returned, and
errno
is set appropriately.
ERRORS
EFAULT
name
is an invalid address.
EINVAL
len
is negative or, for
sethostname(),
len
is larger than the maximum allowed size,
or, for
gethostname()
on Linux/i386,
len
is smaller than the actual size.
(In this last case glibc 2.1 uses
ENAMETOOLONG.)
EPERM
For
sethostname(),
the caller did not have the
CAP_SYS_ADMIN
capability.
CONFORMING TO
SVr4, 4.4BSD (these interfaces first appeared in 4.2BSD).
POSIX.1-2001 specifies
gethostname()
but not
sethostname().
NOTES
SUSv2 guarantees that "Host names are limited to 255 bytes".
POSIX.1-2001 guarantees that "Host names (not including
the terminating null byte) are limited to
HOST_NAME_MAX
bytes".
Glibc Notes
The GNU C library implements
gethostname()
as a library function that calls
uname(2)
and copies up to
len
bytes from the returned
nodename
field into
name.
Having performed the copy, the function then checks if the length of the
nodename
was greater than or equal to
len,
and if it is, then the function returns -1 with
errno
set to
ENAMETOOLONG.
Versions of glibc before 2.2
handle the case where the length of the
nodename
was greater than or equal to
len
differently: nothing is copied into
name
and the function returns -1 with
errno
set to
ENAMETOOLONG.
This page is part of release 3.14 of the Linux
man-pages
project.
A description of the project,
and information about reporting bugs,
can be found at
http://www.kernel.org/doc/man-pages/.
