man pages section 1: User Commands

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Updated: July 2014



uname - print name of current system


uname [-aimnprsvX]
uname [-S system_name]


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:


Prints basic information currently available from the system.


Prints the name of the platform. For machines of the sun4v architecture, the –i option returns: sun4v. Use prtconf(1M) with the –b option to obtain the platform name for a sun4v machine.


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


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


Prints the current host's ISA or processor type.


Prints the operating system release level.


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.


Prints the operating system version.


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)


Example 1 Printing the OS Name and Release Level

The following command prints the operating system name and release level, separated by one SPACE character:

example% uname −sr

Environment Variables

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

Exit Status

The following exit values are returned:


Successful completion.


An error occurred.


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

Interface Stability

See also

arch(1), isalist(1), prtconf(1M), sysinfo(2), uname(2), nodename(4), attributes(5), environ(5), standards(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.