'\"macro stdmacro
.if n .pH g2.sysinfo @(#)sysinfo	40.5 of 10/10/89
.\" Copyright 1989 AT&T
.nr X
.if \nX=0 .ds x} sysinfo 2 "" "" "\&"
.if \nX=1 .ds x} sysinfo 2 "" ""
.if \nX=2 .ds x} sysinfo 2 "" "\&"
.if \nX=3 .ds x} sysinfo "" "" "\&"
.TH \*(x}
.SH NAME
\f4sysinfo\f1 \- get and set system information strings
.SH SYNOPSIS
\f4#include <sys/systeminfo.h>\fP
.PP
\f4long sysinfo (int command, char \(**buf, long count);\fP
.SH DESCRIPTION
\f4sysinfo\fP
copies information relating to the
.SM UNIX
system on which the process is executing into the buffer pointed to by
.IR buf ;
\f4sysinfo\f1 can also set certain information where
appropriate \fIcommands\fP are available.
\f2count\f1 is the size of the buffer.
.PP
The POSIX P1003.1 interface
\f4sysconf\fP [see \f4sysconf\fP(2)]
provides a similar class of configuration information,
but returns an integer rather than a string.
.PP
The
.IR command s
available are:
.TP 0.75i
.SM SI_SYSNAME
Copy into the array pointed to by \fIbuf\fP
the string that would be returned by
\f4uname\fP [see \f4uname\fP(2)]
in the
.IR "sysname " field.
This is the name of the implementation of the operating system, e.g.,
.IR "System V " "or " UTS .
.TP
.SM SI_HOSTNAME
Copy into the array pointed to by \fIbuf\fP
a string that names the present host machine.
This is the string that would be returned by
.IR uname " [see " uname (2)]
in the
.IR "nodename " field.
This hostname or nodename is often the name the machine is known by locally.
.sp
The \fIhostname\fP is the name of this machine as a node in some network;
different networks may have different names for the node,
but presenting the nodename to the appropriate
network Directory or name-to-address mapping service should
produce a transport end point address.
The name may not be fully qualified.
.sp
Internet host names may be up to 256 bytes in
length (plus the terminating null).
.TP
.SM SI_SET_HOSTNAME
Copy the null-terminated contents of the array pointed to by \f2buf\fP
into the string maintained by the kernel whose value will be
returned by succeeding calls to \f4sysinfo\fP with
the command \f4SI_HOSTNAME\fP.
This command requires that the effective-user-id be super-user.
.TP
.SM SI_RELEASE
Copy into the array pointed to by \f2buf\fP
the string that would be returned by
\f4uname\fP  [see \f4uname\fP(2)]
in the
.IR "release " field.
Typical values might be
.IR 4.0 " or " 3.2 .
.TP
.SM SI_VERSION
Copy into the array pointed to by \fIbuf\fP
the string that would be returned by
\f4uname\fP [see \f4uname\fP(2)]
in the
.IR "version " field.
The syntax and semantics of this string are defined by the system provider.
.TP
.SM SI_MACHINE
Copy into the array pointed to by \fIbuf\fP
the string that would be returned by
\f4uname\fP [see \f4uname\fP(2)]
in the
.IR "machine " field,
e.g.,
.IR 3b2 " or " 580 .
.TP
.SM SI_ARCHITECTURE
Copy into the array pointed to by \fIbuf\fP
a string describing the instruction set architecture of the
current system, e.g., \f2mc68030\fP, \f2m32100\fP, or \f2i80486\fP.
These names may not match predefined names in the C language compilation system.
.TP
.SM SI_HW_PROVIDER
Copies the name of the hardware manufacturer into the array
pointed to by \fIbuf\fP.
.TP
.SM SI_HW_SERIAL
Copy into the array pointed to by \f2buf\fP
a string which is the ASCII representation of the
hardware-specific serial number of the physical machine on which the
system call is executed.
Note that this may be implemented in Read-Only Memory, via software
constants set when building the operating system, or by other means,
and may contain non-numeric characters.
It is anticipated that manufacturers will not issue the same ``serial
number'' to more than one physical machine.
The pair of strings returned by \f4SI_HW_PROVIDER\fP
and \f4SI_HW_SERIAL\fP
is likely to be unique across all vendor's System V implementations.
.TP
.SM SI_SRPC_DOMAIN
Copies the Secure Remote Procedure Call
domain name into the array pointed to by \f2buf\fP.
.TP
.SM SI_SET_SRPC_DOMAIN
Set the string to be returned by
\f4sysinfo\fP
with the SI_SRPC_DOMAIN command
to the value contained in the array pointed to by \f2buf\fP.
This command requires that the effective-user-id be super-user.
.P
\f4sysinfo\fP will fail if one or both of the following are true:
.TP
\f4EPERM\f1
The process does not have appropriate privelege for a SET commands.
.TP
\f4EINVAL\f1
\f2buf\fP does not point to a valid address, or the data for
a SET command exceeds the limits established by the implementation.
.SH "DIAGNOSTICS"
Upon successful completion,
the value returned indicates the buffer size in bytes required
to hold the complete value and the terminating null character.
If this value is no greater than the value passed in \f2count\fP,
the entire string was copied;
if this value is greater than \f2count\fP, the string copied into
.I buf
has been truncated to \f2count\-1\fP bytes plus a terminating null character.
.PP
.PD
Otherwise, a value of \-1 is returned and
.I errno\^
is set to indicate the error.
.SH "USAGE"
There is in many cases no corresponding programmatic
interface to set these values;
such strings are typically settable only by the system administrator
modifying entries in the
\f4master.d\f1
directory or the code provided by 
the particular OEM reading a serial number or code out of read-only memory,
or hard-coded in the version of the operating system.
.P
A good starting guess for \f2count\fP is 257, which is likely
to cover all strings returned by this interface in typical installations.
.SH "SEE ALSO"
\f4uname\fP(2), \f4sysconf\fP(2);
.br
BSD compatibility package interfaces gethostname(3), gethostid(3).
