NAME
gethostname() — get name of current host system
SYNOPSIS
#include <unistd.h>
int gethostname(char *hostname, size_t size);
DESCRIPTION
gethostname()
returns in the array to which
hostname
points, the standard host name for the current system as set by
sethostname()
(see
sethostname(2)).
size
specifies the length of the
hostname
array.
hostname
is null-terminated unless insufficient space is provided.
RETURN VALUE
gethostname()
returns
0
if successful.
Otherwise, it returns
-1
and sets
errno
to indicate the error.
ERRORS
gethostname()
can fail if the following is true:
- EFAULT
hostname
points to an illegal address.
The reliable detection of this error is implementation dependent.
- EINVAL
size
is less than one.
WARNINGS
It is recommended that programs use
sysconf(_SC_HOST_NAME_MAX)
to dynamically size the buffer used to accept the host name from
gethostname().
This is preferred over use of the
MAXHOSTNAMELEN
constant.
For cases where the
MAXHOSTNAMELEN
constant must be used, there are
two values: 64 and 256.
The smaller value is compatible with current
releases and is used by default.
To use the larger value consult the
related documentation (see
nodehostnamesize(5)).
The administrator may, with appropriate configuration options enabled,
set a host name larger than 64 bytes.
Existing applications which
were compiled using the smaller
MAXHOSTNAMELEN
to size a buffer passed
to the
gethostname()
system function obtain only the first 64
bytes.
This truncation may cause the applications to exhibit
anomalous behavior or to fail.
AUTHOR
gethostname()
was developed by the University of California, Berkeley.
