Bywater BASIC Interpreter

README file for Bywater BASIC Interpreter/Shell, version 2.50 --------------------------------------------- Copyright (c) 1993, Ted A. Campbell for bwBASIC version 2.10, 11 October 1993 Version 2.20 modifications by Jon B. Volkoff, 25 November 1995 Patch level 1 release by Jon B. Volkoff, 15 March 1996 Patch level 2 release by Jon B. Volkoff, 11 October 1997 Version 2.30 modifications by Paul Edwards, 5 March 2008 Version 2.40 modifications by Paul Edwards, 26 Jan 2009 Version 2.50 modifications by Paul Edwards, 4 June 2009 DESCRIPTION: The Bywater BASIC Interpreter (bwBASIC) implements a large superset of the ANSI Standard for Minimal BASIC (X3.60-1978) and a significant subset of the ANSI Standard for Full BASIC (X3.113-1987) in C. It also offers shell programming facilities as an extension of BASIC. bwBASIC seeks to be as portable as possible. This version of Bywater BASIC is released under the terms of the GNU General Public License (GPL), which is distributed with this software in the file "COPYING". The GPL specifies the terms under which users may copy and use the software in this distribution. A separate license is available for commercial distribution, for information on which you should contact the author. OBTAINING THE SOURCE CODE: The source code for bwBASIC is available from http://bwbasic.sourceforge.net COMMUNICATIONS: email: tcamp@delphi.com (for Ted Campbell) eidetics@cerf.net (for Jon Volkoff) fight.subjugation@gmail.com (for Paul Edwards) A LIST OF BASIC COMMANDS AND FUNCTIONS IMPLEMENTED in bwBASIC: Be aware that many of these commands and functions will not be available unless you have set certain flags in the header files. ABS( number ) ASC( string$ ) ATN( number ) CALL subroutine-name CASE constant | IF partial-expression | ELSE CHAIN file-name CHDIR pathname CHR$( number ) CINT( number ) CLEAR CLOSE [[#]file-number]... CLS COMMON variable [, variable...] COS( number ) CSNG( number ) CVD( string$ ) CVI( string$ ) CVS( string$ ) DATA constant[,constant]... DATE$ DEF FNname(arg...)] = expression DEFDBL letter[-letter](, letter[-letter])... DEFINT letter[-letter](, letter[-letter])... DEFSNG letter[-letter](, letter[-letter])... DEFSTR letter[-letter](, letter[-letter])... DELETE line[-line] DIM variable(elements...)[variable(elements...)]... DO NUM|UNNUM DO [WHILE expression] EDIT (* depends on variable BWB.EDITOR$) ELSE ELSEIF END FUNCTION | IF | SELECT | SUB ENVIRON variable-string$ = string$ ENVIRON$( variable-string ) EOF( device-number ) ERASE variable[, variable]... ERL ERR ERROR number EXIT FOR|DO EXP( number ) FIELD [#] device-number, number AS string-variable [, number AS string-variable...] FILES filespec$ (* depends on variable BWB.FILES$) FOR counter = start TO finish [STEP increment] FUNCTION function-definition GET [#] device-number [, record-number] GOSUB line | label GOTO line | label HEX$( number ) IF expression THEN [statement [ELSE statement]] INKEY$ INPUT [# device-number]|[;]["prompt string";]list of variables INSTR( [start-position,] string-searched$, string-pattern$ ) INT( number ) KILL file-name LEFT$( string$, number-of-spaces ) LEN( string$ ) LET variable = expression LINE INPUT [[#] device-number,]["prompt string";] string-variable$ LIST line[-line] LOAD file-name LOC( device-number ) LOCATE LOF( device-number ) LOG( number ) LOOP [UNTIL expression] LSET string-variable$ = expression MERGE file-name MID$( string$, start-position-in-string[, number-of-spaces ] ) MKD$( number ) MKDIR pathname MKI$( number ) MKS$( number ) NAME old-file-name AS new-file-name NEW NEXT counter OCT$( number ) ON variable GOTO|GOSUB line[,line,line,...] ON ERROR GOSUB line | label OPEN O|I|R, [#]device-number, file-name [,record length] file-name FOR INPUT|OUTPUT|APPEND AS [#]device-number [LEN = record-length] OPTION BASE number POS PRINT [# device-number,][USING format-string$;] expressions... PUT [#] device-number [, record-number] RANDOMIZE number READ variable[, variable]... REM string RENUM RESTORE line RETURN RIGHT$( string$, number-of-spaces ) RMDIR pathname RND( number ) RSET string-variable$ = expression RUN [line]|[file-name] SAVE file-name SELECT CASE expression SGN( number ) SIN( number ) SPACE$( number ) SPC( number ) SQR( number ) STOP STR$( number ) STRING$( number, ascii-value|string$ ) SUB subroutine-name SWAP variable, variable SYSTEM TAB( number ) TAN( number ) TIME$ TIMER TROFF TRON VAL( string$ ) WEND WHILE expression WIDTH [# device-number,] number WRITE [# device-number,] element [, element ].... CHANGE HISTORY CHANGES FROM 2.40 to 2.50 * Bug fixes * New compilation procedure for MVS and CMS CHANGES FROM 2.30 to 2.40 * Bug fixes from Bill Chatfield * Updated documentation * Added support for compiling on CMS (another IBM mainframe OS) CHANGES FROM 2.20pl2 to 2.30 * Minor bug fixes, cosmetic improvements and portability improvements * Added support for compiling on MVS (IBM mainframe) CHANGES FROM 2.20pl1 to 2.20pl2 bwb_cmd.c Fixed calling stack level logic in RETURN statement to prevent erroneous "RETURN without GOSUB" messages. bwb_cnd.c bwb_stc.c Changed continuation condition for WHILE, ELSEIF, and LOOP UNTIL to be != FALSE, not == TRUE. More in line with common commercial BASIC implementations. bwb_mth.c Fixed initialization in VAL function so that old results are not later returned as values. bwb_var.c Added parenthesis level checking to dim_getparams. Using multi-level expressions as array subscripts was causing the program to bomb. bwx_iqc.c bwx_tty.c bwb_mes.h Added second copyright notice. bwb_dio.c bwb_str.c Added support for strings longer than 255 characters. bwb_prn.c Disabled tab expansion and print width checks when not printing to a file. bwb_inp.c Fixed LINE INPUT file reads to accommodate strings of length MAXSTRINGSIZE. bwx_ncu.h bwx_ncu.c New files. Code for UNIX ncurses interface, compliments of L.C. Benschop, Eindhoven, The Netherlands. Makefile.ncu New files. Sample makefile for ncurses implementation. bwbasic.h Revised defines for MININTSIZE and MAXINTSIZE from 16-bit to 32-bit limits. Revised define for MAXSTRINGSIZE from 255 to 5000 characters. Changed string length from unsigned char to unsigned int to support strings longer than 255 characters. Added support for new ncurses package. Revised VERSION define to reflect above changes. CHANGES FROM 2.20 to 2.20pl1 bwb_cnd.c Moved init routine for bwb_while so that it would be initialized regardless of expression value, not just if TRUE. This was causing some segmentation faults in WHILE-WEND loops. bwb_elx.c Plugged gaping memory leak. Temp variable space for expression evaluation was being allocated but not freed when done (oops!). bwb_fnc.c Added check for NULL return from getenv to prevent segmentation faults. bwbasic.h Revised VERSION define to reflect above changes. CHANGES FROM 2.10 to 2.20: * Plugged numerous memory leaks, resolved memory overruns and allocation difficulties. * General cleanup and bug fixes, too many to list in detail here. The major problem areas addressed were: - RUN command with file name argument - nested and cascaded FOR-NEXT loops - PRINT USING - EOF, LOF functions - string concatenation - operator hierarchy - multi-level expression evaluation - hex constant interpretation - hex and octal constants in INPUT and DATA statements * Added a CLOSE all files feature (when no argument supplied). * Added a unary minus sign operator. * Added a MID$ command to complement the MID$ function. * Added a RENUM facility in a standalone program. * Added checking in configure for unistd.h (important on Sun systems).