The uname utility prints information about the current system on the standard output. When options are specified, symbols representing one or more system characteristics will be written to the standard output. If no options are specified, uname prints the current operating system's name. The options print selected information returned by uname(2), sysinfo(2), or both.

The following options are supported:

-a

Prints basic information currently available from the system.

-i

Prints the name of the hardware implementation (platform).

-m

Prints the machine hardware name (class). Use of this option is discouraged; use uname -p instead. See NOTES section below.

-n

Prints the nodename (the nodename is the name by which the system is known to a communications network).

-p

Prints the current host's ISA or processor type.

-r

Prints the operating system release level.

-s

Prints the name of the operating system. This is the default.

-S system_name

The nodename may be changed by specifying a system name argument. The system name argument is restricted to SYS_NMLN characters. SYS_NMLN is an implementation specific value defined in <sys/utsname.h>. Only the super-user is allowed this capability. This change does not persist across reboots of the system. Use sys-unconfig(1M) to change a host's name permanently.

-v

Prints the operating system version.

-X

Prints expanded system information, one information element per line, as expected by SCO UNIX. The displayed information includes:

• system name, node, release, version, machine, and number of CPUs.
• BusType, Serial, and Users (set to "unknown" in Solaris)
• OEM# and Origin# (set to 0 and 1, respectively)

SYSV3

This variable is used to override the default behavior of uname. This is necessary to make it possible for some INTERACTIVE UNIX Systems and SCO UNIX programs and scripts to work properly. Many scripts use uname to determine the SYSV3 type or the version of the OS to ensure software is compatible with that OS. Setting SYSV3 to an empty string will make uname print the following default values:

nodename nodename 3.2 2 i386

The individual elements that uname displays can also be modified by setting SYSV3 in the following format:

os,sysname,node,rel,ver,mach

os

Operating system (IUS or SCO).

sysname

System name.

node

Nodename as displayed by the -n option.

rel

Release level as displayed by the -r option.

ver

Version number as displayed by the -v option.

mach

Machine name as displayed by -m option.

Do not put spaces between the elements. If an element is omitted, the current system value will be used.

See environ(5) for descriptions of the following environment variables that affect the execution of uname: LC_CTYPE, LC_MESSAGES, and NLSPATH.

The following exit values are returned:

0

Successful completion.

>0

An error occurred.

See attributes(5) for descriptions of the following attributes:

arch(1), isalist(1), sys-unconfig(1M), sysinfo(2), uname(2), nodename(4), attributes(5), environ (5)

Independent software vendors (ISVs) and others who need to determine detailed characteristics of the platform on which their software is either being installed or executed should use the uname command.

To determine the operating system name and release level, use uname -sr. To determine only the operating system release level, use uname -r. Notice that operating system release levels are not guaranteed to be in x.y format (such as 5.3, 5.4, 5.5, and so forth); future releases could be in the x.y.z format (such as 5.3.1, 5.3.2, 5.4.1, and so forth).

In SunOS 4.x releases, the arch(1) command was often used to obtain information similar to that obtained by using the uname command. The arch(1) command output "sun4" was often incorrectly interpreted to signify a SunOS SPARC system. If hardware platform information is desired, use uname -sp.

The arch -k and uname -m commands return equivalent values; however, the use of either of these commands by third party programs is discouraged, as is the use of the arch command in general. To determine the machine's Instruction Set Architecture (ISA or processor type), use uname with the -p option.