UNAME(1) General Commands Manual UNAME(1)

uname — return system name

uname [-amnrsv]

By default, the uname utility shall write the operating system name to standard output. When options are specified, symbols representing one or more system characteristics shall be written to the standard output. The format and contents of the symbols are implementation defined. On systems conforming to POSIX. 1 {8}, the symbols written shall be those supported by the POSIX. 1 {8} uname function.

The uname utility shall conform to the utility argument syntax guidelines described in 2.10.2. The following options shall be supported by the implementation:

Behave as though all of the options −mnrsv were specified.

Write the name of the hardware type on which the system is running to standard output.

Write the name of this node within an implementation-specified communications network.

Write the current release level of the operating system implementation.

Write the name of the implementation of the operating system.

Write the current version level of this release of the operating system implementation. If no options are specified, the uname utility shall write the operating system name, as if the −s option had been specified.

None.

None.

None.

The following environment variables shall affect the execution of uname:

This variable shall determine the locale to use for the locale categories when both LC_ALL and the corresponding environment variable (beginning with LC_ ) do not specify a locale. See 2.6.

This variable shall determine the locale to be used to override any values for locale categories specified by the settings of LANG or any environment variables beginning with LC_.

This variable shall determine the locale for the interpretation of sequences of bytes of text data as characters (e.g., single- versus multibyte characters in arguments).

This variable shall determine the language in which messages should be written.

Default.

By default, the output shall be a single line of the following form: "%s\n", <sysname> If the −a option is specified, the output shall be a single line of the following form: "%s %s %s %s %s\n", <sysname>, <nodename>, <release>, <version>, <machine> Additional implementation-defined symbols may be written; all such symbols shall be written at the end of the line of output before the <newline>.

If options are specified to select different combinations of the symbols, only those symbols shall be written, in the order shown above for the −a option. If a symbol is not selected for writing, its corresponding trailing <blank>s also shall not be written.

Used only for diagnostic messages.

None.

None.

The uname utility shall exit with one of the following values:

The requested information was successfully written.

An error occurred.

Default.

The following command: uname −sr writes the operating system name and release level, separated by one or more <blank>s. Note that any of the symbols could include embedded <space>s, which may affect parsing algorithms if multiple options are selected for output. The node name is typically a name that the system uses to identify itself for intersystem communication addressing.

It was suggested that this utility cannot be used portably, since the format of the symbols is implementation defined. The POSIX. 1 {8} working group could not achieve consensus on defining these formats in the underlying uname function and there is no expectation that POSIX. 2 would be any more successful. In any event, some applications may still find this historical utility of value. For example, the symbols could be used for system log entries or for comparison with operator or user input.

September 1991 posix.fail