EnvVar                 package:base                 R Documentation

_E_n_v_i_r_o_n_m_e_n_t _V_a_r_i_a_b_l_e_s

_D_e_s_c_r_i_p_t_i_o_n:

     Details of some of the environment variables which affect an R
     session.

_D_e_t_a_i_l_s:

     It is impossible to list all the environment variables which can
     affect an R session: some affect the OS system functions which R
     uses, and others will affect add-on packages.  But here are notes
     on some of the more important ones.  Those that set the defaults
     for options are consulted only at startup (as are some of the
     others).

     '_H_O_M_E': The user's 'home' directory.

     '_L_A_N_G_U_A_G_E': Optional.  The language(s) to be used for message
          translations.  This is consulted when needed.

     '_L_C__A_L_L': (etc) Optional.  Use to set various aspects of the
          locale - see 'Sys.getlocale'.  Consulted at startup.

     '_R__B_A_T_C_H': Optional - set in a batch session.

     '_R__B_R_O_W_S_E_R': The path to the default browser.  Used to set the
          default value of 'options("browser")'.

     '_R__C_O_M_P_L_E_T_I_O_N': Optional.  If set to 'FALSE', comand-line
          completion is not used.  (Not used by Mac OS GUI.)

     '_R__D_E_F_A_U_L_T__P_A_C_K_A_G_E_S': A comma-separated list of packages which are
          to be loaded in every session.  See 'options'.

     '_R__D_O_C__D_I_R': The location of the R 'doc' directory.  Set by R.

     '_R__D_V_I_P_S_C_M_D': The path to 'dvips'.  Defaults to the value of
          'DVIPS', and if that is unset to a value determined when R
          was built. Used by 'R CMD Rd2dvi', and at startup to set the
          default for 'options("latexcmd")', used by 'help(offline =
          TRUE'.

     '_R__E_N_V_I_R_O_N': Optional.  The path to the site environment file: see
          Startup.  Consulted at startup.

     '_R__G_S_C_M_D': Optional.  The path to GhostScript, used by
          'dev2bitmap'.

     '_R__H_I_S_T_F_I_L_E': Optional.  The path of the history file: see
          Startup.  Consulted at startup and when the history is saved.

     '_R__H_I_S_T_S_I_Z_E': Optional.  The maximum size of the history file, in
          lines.  Exactly how this is used depends on the interface.
          For the 'readline' command-line interface it takes effect
          when the history is saved (by 'savehistory' or at the end of
          a session).

     '_R__H_O_M_E': The top-level directory of the R installation: see
          'R.home'.  Set by R.

     '_R__I_N_C_L_U_D_E__D_I_R': The location of the R 'include' directory.  Set
          by R.

     '_R__L_A_T_E_X_C_M_D': The path to 'latex'. Defaults to the value of
          'LATEX', and if that is unset to a value determined when R
          was built. Used by 'R CMD Rd2dvi', and at startup to set the
          default for 'options("latexcmd")', used by 'help(offline =
          TRUE'.

     '_R__L_I_B_S': Optional.  Used for initial setting of '.libPaths'.

     '_R__L_I_B_S__S_I_T_E': Optional.  Used for initial setting of '.libPaths'.

     '_R__L_I_B_S__U_S_E_R': Optional.  Used for initial setting of '.libPaths'.

     '_R__M_A_K_E_I_N_D_E_X_C_M_D': The path to 'makeindex'.  Defaults at startup to
          the value of 'MAKEINDEX', and if that is unset to a value
          determined when R was built.  Used by 'R CMD Rd2dvi'.

     '_R__P_A_P_E_R_S_I_Z_E': Optional.  Use to set the default for
          'options("papersize")', e.g. used by 'pdf', 'postscript' and
          'help(offline = TRUE)'.

     '_R__P_D_F_L_A_T_E_X_C_M_D': The path to 'pdflatex'.  Defaults at startup to
          the value of 'PDFLATEX', and if that is unset to a value
          determined when R was built.  Used by 'R CMD Rd2dvi'.

     '_R__P_D_F_V_I_E_W_E_R': The path to the default PDF viewer.  Used by 'R CMD
          Rd2dvi'.

     '_R__P_L_A_T_F_O_R_M': The platform - a string of the form 'cpu-vendor-os',
          see 'R.Version'.

     '_R__P_R_O_F_I_L_E': Optional.  The path to the site profile file: see
          Startup.  Consulted at startup.

     '_R__R_D_4_D_V_I': Options for 'latex' processing of 'Rd' files.  Used by
          'R CMD Rd2dvi' and 'help(offline = TRUE)'.

     '_R__R_D_4_P_D_F': Options for 'pdflatex' processing of 'Rd' files.  Used
          by 'R CMD Rd2dvi'.

     '_R__S_H_A_R_E__D_I_R': The location of the R 'share' directory.  Set by R. 

     '_R__T_E_X_I_2_D_V_I_C_M_D': The path to 'texi2dvi'. Defaults to the value of
          'TEXI2DVI', and if that is unset to a value determined when R
          was built. Consulted at startup to set the default for
          'options("texi2dvi")', used by 'texi2dvi' in package 'tools'.

     '_R__U_N_Z_I_P_C_M_D': The path to 'unzip'.  Sets the default value for
          'options("unzip")'.

     '_R__Z_I_P_C_M_D': The path to 'zip'.

     '_T_M_P_D_I_R', '_T_M_P', '_T_E_M_P': Consulted (in that order) when setting
          the temporary directory.  See 'tempdir'.

     '_T_Z': Optional. The current timezone.  See 'Sys.timezone' for the
          system-specific formats.  Consulted as needed.

     '_n_o__p_r_o_x_y', '_h_t_t_p__p_r_o_x_y', '_f_t_p__p_r_o_x_y': (and more).  Optional. 
          Settings for 'download.file': see its help for further
          details.

_U_n_i_x-_s_p_e_c_i_f_i_c:

     Some variables set on Unix-alikes, and not (in general) on
     Windows.

     '_D_I_S_P_L_A_Y': Optional: used by 'X11', Tk (in package 'tcltk'), the
          data editor and various packages.

     '_E_D_I_T_O_R': The path to the default editor.

     '_P_A_G_E_R': The path to the default pager.

     '_R__P_R_I_N_T_C_M_D': Sets the default for 'options("printcmd")', which
          sets the default print command to be used by 'postscript'.

_S_e_e _A_l_s_o:

     'Sys.getenv' and 'Sys.setenv' to read and set environmental
     variables in an R session.