g.gisenv(1)	       Grass User's Manual	      g.gisenv(1)



NNAAMMEE
       gg..ggiisseennvv  - Outputs the user's current GRASS variable set-
       tings.
       _(_G_R_A_S_S _F_i_l_e _M_a_n_a_g_e_m_e_n_t _P_r_o_g_r_a_m_)

SSYYNNOOPPSSIISS
       gg..ggiisseennvv
       gg..ggiisseennvv [_v_a_r_i_a_b_l_e___n_a_m_e]

DDEESSCCRRIIPPTTIIOONN
       When a user runs GRASS, certain variables are set specify-
       ing  the  GRASS	data  base,  location, mapset, peripheral
       device drivers, etc., being used in the current GRASS ses-
       sion.  These variable name settings are recognized as long
       as the user is running a GRASS session.

OOPPTTIIOONNSS
       No prompts are given to the user  when  running	_g_._g_i_s_e_n_v.
       If run without arguments, _g_._g_i_s_e_n_v lists all of the user's
       current GRASS variable  settings.   Results  are  sent  to
       standard   output,   and   may	look   like  this:  GISD-
       BASE=/usr/grass4/data

       LOCATION_NAME=spearfish

       MAPSET=PERMANENT

       In this example, the full path name of the user's  current
       location 	(i.e.,	       $LOCATION_NAME)	       is
       /usr/grass4/data/spearfish, and the full path name of  the
       user's	  current     mapset	 (i.e.,    $MAPSET)    is
       /usr/grass4/data/spearfish/PERMANENT.


       If the user specifies a _v_a_r_i_a_b_l_e___n_a_m_e on the command  line
       (e.g.,  gg..ggiisseennvv MMAAPPSSEETT), only the value for that particu-
       lar GRASS variable is output to standard output.  Possible
       variable names depend on the user's system.


       While  other  variables	may be associated with each GRASS
       session (e.g.,  DIGITIZER,  PAINTER,  DISPLAY,  and  other
       variables), those stated below are essential.

       _G_I_S_D_B_A_S_E
	      The  $GISDBASE  is  a directory in which all users'
	      GRASS data are stored.  Within the $GISDBASE,  data
	      are  segregated  into subdirectories (called "loca-
	      tions") based on the map coordinate system used and
	      the geographic extent of the data.  Each "location"
	      directory  itself  contains  subdirectories  called
	      "mapsets";  each	"mapset"  stores  "data base ele-
	      ments" -- the directories (e.g., the cell,  cellhd,
	      dig,  etc.,  directories) in which GRASS data files
	      are actually stored.

       _L_O_C_A_T_I_O_N___N_A_M_E
	      The user must choose to work with the data under	a
	      single  GRASS  location within any given GRASS ses-
	      sion; this location  is  then  called  the  _c_u_r_r_e_n_t
	      _G_R_A_S_S  _l_o_c_a_t_i_o_n,	and  is specified by the variable
	      $LOCATION_NAME.  The $LOCATION_NAME  is  the  GRASS
	      data  base  location whose data will be affected by
	      any GRASS commands issued during the user's current
	      GRASS session, and is a subdirectory of the current
	      $GISDBASE.  Each "location" directory  can  contain
	      multiple	"mapset"  directories (including the spe-
	      cial mapset PERMANENT).  Maps stored under the same
	      GRASS LOCATION_NAME (and/or within the same MAPSET)
	      must use the same coordinate system  and	typically
	      fall  within  the boundaries of the same geographic
	      region (aka, "location").

       _M_A_P_S_E_T Each "mapset" contains a set of  maps  relevant  to
	      the  LOCATION_NAME  directory  in which it appears.
	      Each LOCATION_NAME can  contain  multiple  mapsets.
	      (Mapsets	which  fall  under the same LOCATION_NAME
	      all contain data	geographically	relevant  to  the
	      LOCATION_NAME,  and  all store data in the same map
	      coordinate system.   Frequently,	maps  are  placed
	      into  different  mapsets to distinguish file owner-
	      ship -- e.g., each user might have his own  mapset,
	      storing  any  maps  that	he has created and/or are
	      relevant to his work.) During each  GRASS  session,
	      the  user  must choose one mapset to be the _c_u_r_r_e_n_t
	      _m_a_p_s_e_t;  the current mapset  setting  is	given  by
	      $MAPSET,	and  is a subdirectory of $LOCATION_NAME.
	      During a single GRASS session,  the  user  can  use
	      available  data  in any of the mapsets stored under
	      the current LOCATION_NAME directory that are in the
	      user's  mapset  search  path  and accessible by the
	      user.  However, within a single GRASS session,  the
	      user only has _w_r_i_t_e access to data stored under the
	      _c_u_r_r_e_n_t _m_a_p_s_e_t (specified by the variable $MAPSET).


       Each  "mapset"  stores GRASS data base elements (i.e., the
       directories in which GRASS data files  are  stored).   Any
       maps  created or modified by the user in the current GRASS
       session will be stored here.  The MAPSET directory  PERMA-
       NENT  is  generally reserved for the set of maps that form
       the base set  for  all  users  working  under  each  LOCA-
       TION_NAME.

       Once  within a GRASS session, GRASS users have access only
       to the data under a single GRASS data base directory  (the
       _c_u_r_r_e_n_t	_G_R_A_S_S _d_a_t_a _b_a_s_e, specified by the variable $GISD-
       BASE), and to a single GRASS location directory (the  _c_u_r_-
       _r_e_n_t  _l_o_c_a_t_i_o_n, specified by the variable $LOCATION_NAME).
       Within a single session, the user may only _m_o_d_i_f_y the data
       in the _c_u_r_r_e_n_t _m_a_p_s_e_t (specified by the variable $MAPSET),
       but may _u_s_e data available under other mapsets  under  the
       same LOCATION_NAME.


       All  of these names must be legal names on the user's cur-
       rent system.  For UNIX users, names less than  14  charac-
       ters  and  containing  no  non-printing or space codes are
       permissible.  Examples of permissible names include:  _o_n_e,
       _m_y_m_a_p,  _V_e_G_e___m_a_p,  and _1___f_o_r___m_e.  The underscore character
       can safely be used in place of a blank  for  multiple-word
       names.

NNOOTTEESS
       The output from _g_._g_i_s_e_n_v when invoked without arguments is
       directly usable by /bin/sh.  The  following  command  will
       cast each variable into the UNIX environment:


       eevvaall ``gg..ggiisseennvv``



       This  works  only for _/_b_i_n_/_s_h. The format of the output is
       not compatible with other UNIX shells.

SSEEEE AALLSSOO
       _g_._a_c_c_e_s_s

       _g_._a_s_k

       _g_._f_i_l_e_n_a_m_e

       _g_._f_i_n_d_f_i_l_e

       _g_._m_a_p_s_e_t_s

AAUUTTHHOORR
       Michael	 Shapiro,   U.S.Army   Construction   Engineering
       Research Laboratory

       _L_a_s_t _c_h_a_n_g_e_d_: _$_D_a_t_e_: _2_0_0_2_/_0_1_/_2_5 _0_5_:_4_5_:_3_3 _$



GRASS 5.0					      g.gisenv(1)
