Manual Pages  — UNAME

uname – display information about the system

SYNOPSIS DESCRIPTION ENVIRONMENT EXIT STATUS EXAMPLES SEE ALSO STANDARDS HISTORY

uname [-aiKmnoprsUv]

The uname command writes the name of the operating system implementation to standard output. When options are specified, strings representing one or more system characteristics are written to standard output.

The options are as follows:

-a
	Behave as though the options -m -, -n -, -r -, -s, and -v were specified.
-i
	Write the kernel ident to standard output.
-K
	Write the FreeBSD version of the kernel.
-m
	Write the type of the current hardware platform to standard output. (make(1) uses it to set the MACHINE variable. )
-n
	Write the name of the system to standard output.
-o
	This is a synonym for the -s option, for compatibility with other systems.
-p
	Write the type of the machine processor architecture to standard output. (make(1) uses it to set the MACHINE_ARCH variable. )
-r
	Write the current release level of the operating system to standard output.
-s
	Write the name of the operating system implementation to standard output.
-U
	Write the FreeBSD version of the user environment.
-v
	Write the version level of this release of the operating system to standard output.

If the -a flag is specified, or multiple flags are specified, all output is written on a single line, separated by spaces.

The -K and -U flags are intended to be used for fine grain differentiation of incremental FreeBSD development and user visible changes.

An environment variable composed of the string UNAME_ followed by any flag to the uname utility (except for -a) will allow the corresponding data to be set to the contents of the environment variable.

The utility exits 0 on success, and >0 if an error occurs.

The hardware platform (-m) can be different from the machine's processor architecture (-p), e.g., on 64-bit PowerPC, -m would return powerpc and -p would return powerpc64.

The uname command is expected to conform to the IEEE Std 1003.2 ("POSIX.2") specification.

The uname command appeared in PWB UNIX 1.0, however BSD 4.4 was the first Berkeley release with the uname command.

The -K and -U extension flags appeared in FreeBSD 10.0 .