sysinfo(2) —

NAME

sysinfo − get and set system information strings

SYNOPSIS

#include <sys/systeminfo.h>

long sysinfo (int command, char ∗buf, long count);

DESCRIPTION

sysinfo copies information relating to the UNIX system on which the process is executing into the buffer pointed to by buf; sysinfo can also set certain information where appropriate commands are available. count is the size of the buffer.

The POSIX P1003.1 interface sysconf [see sysconf(2)] provides a similar class of configuration information, but returns an integer rather than a string.

The commands available are:

SI_SYSNAME Copy into the array pointed to by buf the string that would be returned by uname [see uname(2)] in the sysname field. This is the name of the implementation of the operating system, for example, System V or UTS.

SI_HOSTNAME
Copy into the array pointed to by buf a string that names the present host machine. This is the string that would be returned by uname [see uname(2)] in the nodename field. This hostname or nodename is often the name the machine is known by locally. The hostname 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. Internet host names may be up to 256 bytes in length (plus the terminating null).

SI_SET_HOSTNAME
Copy the null-terminated contents of the array pointed to by buf into the string maintained by the kernel whose value will be returned by succeeding calls to sysinfo with the command SI_HOSTNAME. This command requires that the effective-user-id be super-user.

SI_RELEASE Copy into the array pointed to by buf the string that would be returned by uname [see uname(2)] in the release field. Typical values might be 4.0 or 3.2.

SI_VERSION Copy into the array pointed to by buf the string that would be returned by uname [see uname(2)] in the version field. The syntax and semantics of this string are defined by the system provider.

SI_MACHINE Copy into the array pointed to by buf the string that would be returned by uname [see uname(2)] in the machine field, for example, 3b2 or 580.

SI_ARCHITECTURE
Copy into the array pointed to by buf a string describing the instruction set architecture of the current system, for example, mc68030, m32100, or i80486. These names may not match predefined names in the C language compilation system.

SI_HW_PROVIDER
Copies the name of the hardware manufacturer into the array pointed to by buf.

SI_HW_SERIAL
Copy into the array pointed to by buf 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 SI_HW_PROVIDER and SI_HW_SERIAL is likely to be unique across all vendor’s System V implementations.

SI_SRPC_DOMAIN
Copies the Secure Remote Procedure Call domain name into the array pointed to by buf.

SI_SET_SRPC_DOMAIN
Set the string to be returned by sysinfo with the SI_SRPC_DOMAIN command to the value contained in the array pointed to by buf. This command requires that the effective-user-id be super-user.

sysinfo will fail if one or both of the following are true:

EPERM The process does not have appropriate privilege for a SET commands.

EINVAL buf does not point to a valid address, or the data for a SET command exceeds the limits established by the implementation.

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 count, the entire string was copied; if this value is greater than count, the string copied into buf has been truncated to count−1 bytes plus a terminating null character.

Otherwise, a value of −1 is returned and errno is set to indicate the error.

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 master.d 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.

A good starting guess for count is 257, which is likely to cover all strings returned by this interface in typical installations.

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