gethostname.3

早期freebsd实现

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.\"     @(#)gethostname.3	8.1 (Berkeley) 6/4/93
.\"
.Dd June 4, 1993
.Dt GETHOSTNAME 3
.Os BSD 4.2
.Sh NAME
.Nm gethostname ,
.Nm sethostname
.Nd get/set name of current host
.Sh SYNOPSIS
.Fd #include <unistd.h>
.Ft int
.Fn gethostname "char *name" "int namelen"
.Ft int
.Fn sethostname "const char *name" "int namelen"
.Sh DESCRIPTION
.Fn Gethostname
returns the standard host name for the current processor, as
previously set by
.Fn sethostname .
The parameter
.Fa namelen
specifies the size of the 
.Fa name
array.  The returned name is null-terminated unless insufficient
space is provided.
.Pp
.Fn Sethostname
sets the name of the host machine to be
.Fa name ,
which has length
.Fa namelen .
This call is restricted to the super-user and
is normally used only when the system is bootstrapped.
.Sh RETURN VALUES
If the call succeeds a value of 0 is returned.  If the call
fails, a value of -1 is returned and an error code is
placed in the global location
.Va errno .
.Sh ERRORS
The following errors may be returned by these calls:
.Bl -tag -width Er
.It Bq Er EFAULT
The
.Fa name
or
.Fa namelen
parameter gave an
invalid address.
.It Bq Er EPERM
The caller tried to set the hostname and was not the super-user.
.El
.Sh SEE ALSO
.Xr sysctl 2
.Xr gethostid 3
.Sh BUGS
Host names are limited to
.Dv MAXHOSTNAMELEN
(from
.Ao Pa sys/param.h Ac )
characters, currently 256.
.Sh HISTORY
The
.Nm
function call appeared in
.Bx 4.2 .