NAME . - oldvalue SYNOPSIS . (with no adjacent letters or digits or _ or .) TYPES return any DESCRIPTION The "old value" is essentially a global variable with identifier "." which at top level when directly from a file or keyboard is automatically assigned the saved value for a line of statements when evaluation of that line is completed and this saved value is not null. A line of statements is normally completed by a '\n' not within a block bounded by braces or an expression bounded by parentheses. Disabling of saving by calling saveval(0) causes lines to return a null value and . then becomes in effect a global variable whose value may be changed by assignments and operations like ++ and --. A null value may be assigned to . by . = null() or free(.). EXAMPLE ; saveval(1); ; a = 2 ; . 2 ; . += 3; b = . + 4 ; print ., b 9 9 ; . += 3; b = . + 4; null() ; print ., b 12 16 ; list(a, b, a + b) list (3 elements, 3 nonzero): [[0]] = 2 [[1]] = 16 [[2]] = 18 ; saveval(0) ; print pop(.), .[[1]] 2 18 LIMITS none LINK LIBRARY none SEE ALSO saveval ## Copyright (C) 1999 Landon Curt Noll ## ## Calc is open software; you can redistribute it and/or modify it under ## the terms of the version 2.1 of the GNU Lesser General Public License ## as published by the Free Software Foundation. ## ## Calc is distributed in the hope that it will be useful, but WITHOUT ## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY ## or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General ## Public License for more details. ## ## A copy of version 2.1 of the GNU Lesser General Public License is ## distributed with calc under the filename COPYING-LGPL. You should have ## received a copy with calc; if not, write to Free Software Foundation, Inc. ## 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. ## ## @(#) $Revision: 30.1 $ ## @(#) $Id: oldvalue,v 30.1 2007/03/16 11:10:42 chongo Exp $ ## @(#) $Source: /usr/local/src/cmd/calc/help/RCS/oldvalue,v $ ## ## Under source code control: 1997/09/06 20:03:35 ## File existed as early as: 1997 ## ## chongo /\oo/\ http://www.isthe.com/chongo/ ## Share and enjoy! :-) http://www.isthe.com/chongo/tech/comp/calc/