UNAME(1)                   POSIX Programmer's Manual                  UNAME(1)



PPRROOLLOOGG
       This manual page is part of the POSIX Programmer's Manual.  The OS
       implementation of this interface may differ (consult the corresponding
       OS manual page for details of OS behavior), or the interface may not be
       implemented on OS.

NNAAMMEE
       uname -- return system name

SSYYNNOOPPSSIISS
       uname [[-amnrsv]]

DDEESSCCRRIIPPTTIIOONN
       By default, the _u_n_a_m_e 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 the System Interfaces volume of POSIX.1-2017, the
       symbols written shall be those supported by the _u_n_a_m_e() function as
       defined in the System Interfaces volume of POSIX.1-2017.

OOPPTTIIOONNSS
       The _u_n_a_m_e utility shall conform to the Base Definitions volume of
       POSIX.1-2017, _S_e_c_t_i_o_n _1_2_._2, _U_t_i_l_i_t_y _S_y_n_t_a_x _G_u_i_d_e_l_i_n_e_s.

       The following options shall be supported:

       --aa        Behave as though all of the options --mmnnrrssvv were specified.

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

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

       --rr        Write the current release level of the operating system
                 implementation.

       --ss        Write the name of the implementation of the operating system.

       --vv        Write the current version level of this release of the
                 operating system implementation.

       If no options are specified, the _u_n_a_m_e utility shall write the
       operating system name, as if the --ss option had been specified.

OOPPEERRAANNDDSS
       None.

SSTTDDIINN
       Not used.

IINNPPUUTT FFIILLEESS
       None.

EENNVVIIRROONNMMEENNTT VVAARRIIAABBLLEESS
       The following environment variables shall affect the execution of
       _u_n_a_m_e:

       _L_A_N_G      Provide a default value for the internationalization
                 variables that are unset or null. (See the Base Definitions
                 volume of POSIX.1-2017, _S_e_c_t_i_o_n _8_._2, _I_n_t_e_r_n_a_t_i_o_n_a_l_i_z_a_t_i_o_n
                 _V_a_r_i_a_b_l_e_s for the precedence of internationalization
                 variables used to determine the values of locale categories.)

       _L_C___A_L_L    If set to a non-empty string value, override the values of
                 all the other internationalization variables.

       _L_C___C_T_Y_P_E  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).

       _L_C___M_E_S_S_A_G_E_S
                 Determine the locale that should be used to affect the format
                 and contents of diagnostic messages written to standard
                 error.

       _N_L_S_P_A_T_H   Determine the location of message catalogs for the processing
                 of _L_C___M_E_S_S_A_G_E_S.

AASSYYNNCCHHRROONNOOUUSS EEVVEENNTTSS
       Default.

SSTTDDOOUUTT
       By default, the output shall be a single line of the following form:


           "%s\n", <_s_y_s_n_a_m_e>

       If the --aa option is specified, the output shall be a single line of the
       following form:


           "%s %s %s %s %s\n", <_s_y_s_n_a_m_e>, <_n_o_d_e_n_a_m_e>, <_r_e_l_e_a_s_e>,
               <_v_e_r_s_i_o_n>, <_m_a_c_h_i_n_e>

       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 --aa option. If a symbol is not selected for writing, its
       corresponding trailing <blank> characters also shall not be written.

SSTTDDEERRRR
       The standard error shall be used only for diagnostic messages.

OOUUTTPPUUTT FFIILLEESS
       None.

EEXXTTEENNDDEEDD DDEESSCCRRIIPPTTIIOONN
       None.

EEXXIITT SSTTAATTUUSS
       The following exit values shall be returned:

        0    The requested information was successfully written.

       >0    An error occurred.

CCOONNSSEEQQUUEENNCCEESS OOFF EERRRROORRSS
       Default.

       _T_h_e _f_o_l_l_o_w_i_n_g _s_e_c_t_i_o_n_s _a_r_e _i_n_f_o_r_m_a_t_i_v_e_.

AAPPPPLLIICCAATTIIOONN UUSSAAGGEE
       Note that any of the symbols could include embedded <space> characters,
       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 inter-system communication addressing.

EEXXAAMMPPLLEESS
       The following command:


           uname -sr

       writes the operating system name and release level, separated by one or
       more <blank> characters.

RRAATTIIOONNAALLEE
       It was suggested that this utility cannot be used portably since the
       format of the symbols is implementation-defined. The POSIX.1 working
       group could not achieve consensus on defining these formats in the
       underlying _u_n_a_m_e() function, and there was no expectation that this
       volume of POSIX.1-2017 would be any more successful. 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.

FFUUTTUURREE DDIIRREECCTTIIOONNSS
       None.

SSEEEE AALLSSOO
       The Base Definitions volume of POSIX.1-2017, _C_h_a_p_t_e_r _8, _E_n_v_i_r_o_n_m_e_n_t
       _V_a_r_i_a_b_l_e_s, _S_e_c_t_i_o_n _1_2_._2, _U_t_i_l_i_t_y _S_y_n_t_a_x _G_u_i_d_e_l_i_n_e_s

       The System Interfaces volume of POSIX.1-2017, _u_n_a_m_e()

CCOOPPYYRRIIGGHHTT
       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1-2017, Standard for Information Technology --
       Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the
       Institute 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.opengroup.org/unix/online.html .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the source
       files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .



IEEE/The Open Group                  2017                             UNAME(1)
