uname(P) uname(P) NAME uname - return system name SYNOPSIS uname [-snrvma] DESCRIPTION By default, the uname utility shall write the operating system name to standard output. When options are speci- fied, symbols representing one or more system character- istics shall be written to the standard output. The for- mat and contents of the symbols are implementation- defined. On systems conforming to the System Interfaces volume of IEEE Std 1003.1-2001, the symbols written shall be those supported by the uname() function as defined in the System Interfaces volume of IEEE Std 1003.1-2001. OPTIONS The uname utility shall conform to the Base Definitions volume of IEEE Std 1003.1-2001, Section 12.2, Utility Syntax Guidelines. The following options shall be supported: -a Behave as though all of the options -mnrsv were specified. -m Write the name of the hardware type on which the system is running to standard output. -n Write the name of this node within an implementa- tion-defined communications network. -r Write the current release level of the operating system implementation. -s Write the name of the implementation of the oper- ating system. -v 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. OPERANDS None. STDIN Not used. INPUT FILES None. ENVIRONMENT VARIABLES The following environment variables shall affect the execution of uname: LANG Provide a default value for the internationaliza- tion variables that are unset or null. (See the Base Definitions volume of IEEE Std 1003.1-2001, Section 8.2, Internationalization Variables for the precedence of internationalization variables used to determine the values of locale cate- gories.) LC_ALL If set to a non-empty string value, override the values of all the other internationalization variables. LC_CTYPE Determine the locale for the interpretation of sequences of bytes of text data as characters (for example, single-byte as opposed to multi- byte characters in arguments). LC_MESSAGES Determine the locale that should be used to affect the format and contents of diagnostic mes- sages written to standard error. NLSPATH Determine the location of message catalogs for the processing of LC_MESSAGES . ASYNCHRONOUS EVENTS Default. STDOUT By default, the output shall be a single line of the following form: "%s\n", If the -a option is specified, the output shall be a single line of the following form: "%s %s %s %s %s\n", , , , , Additional implementation-defined symbols may be writ- ten; all such symbols shall be written at the end of the line of output before the . If options are specified to select different combina- tions of the symbols, only those symbols shall be writ- ten, in the order shown above for the -a option. If a symbol is not selected for writing, its corresponding trailing s also shall not be written. STDERR The standard error shall be used only for diagnostic messages. OUTPUT FILES None. EXTENDED DESCRIPTION None. EXIT STATUS The following exit values shall be returned: 0 The requested information was successfully writ- ten. >0 An error occurred. CONSEQUENCES OF ERRORS Default. The following sections are informative. APPLICATION USAGE Note that any of the symbols could include embedded s, which may affect parsing algorithms if multi- ple options are selected for output. The node name is typically a name that the system uses to identify itself for inter-system communication addressing. EXAMPLES The following command: uname -sr writes the operating system name and release level, sep- arated by one or more s. RATIONALE It was suggested that this utility cannot be used portably since the format of the symbols is implementa- tion-defined. The POSIX.1 working group could not achieve consensus on defining these formats in the underlying uname() function, and there was no expecta- tion that this volume of IEEE Std 1003.1-2001 would be any more successful. Some applications may still find this historical utility of value. For example, the sym- bols could be used for system log entries or for compar- ison with operator or user input. FUTURE DIRECTIONS None. SEE ALSO The System Interfaces volume of IEEE Std 1003.1-2001, uname() COPYRIGHT Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable Operat- ing System Interface (POSIX), The Open Group Base Speci- fications Issue 6, Copyright (C) 2001-2003 by the Insti- tute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.open- group.org/unix/online.html . POSIX 2003 uname(P)