BCHELP.PAS

unit BCHELP;

interface

  procedure ShowCommands;

implementation

  uses Dos, Crt;

  procedure ShowCommands;

  procedure Pause;
    var
      C: Char;
  begin
    Write ('-- More --');
    C := ReadKey;
    if C = #0 then C := ReadKey;
    WriteLn;
  end;

  begin
    WriteLn;
    WriteLn ('DOS commands:');
    WriteLn;
    WriteLn ('BREAK [on | off]       Turn BREAK on or off.');
    WriteLn ('CALL ...               Run a batch file and return to your program.');
    WriteLn ('CD/CHDIR ...           Change directory.');
    WriteLn ('CLS                    Clear the screen or the current window.');
    WriteLn ('COMMAND [/c ...]       Run COMMAND.COM.');
    WriteLn ('COPY ...               Copy file(s) (COPY is handled by COMMAND.COM).');
    WriteLn ('DEL/ERASE ...          Delete file(s).');
    WriteLn ('DIR [/p][/w]           Show a list of files in a directory.');
    WriteLn ('ECHO ...               Write text to the screen.');
    WriteLn ('EXIT                   Exit program and return to DOS.');
    WriteLn ('FOR %%C in (list)      Set the variable %%C to all items of list and');
    WriteLn ('  do ...               perform a command.');
    WriteLn ('GOTO label             Go to another line in the batch file');
    WriteLn ('                       (a label is any word after a colon ":").');
    WriteLn ('IF [NOT] EXIST ...     If the file exists, then ...');
    WriteLn ('IF ERRORLEVEL x ...    If the ERRORLEVEL is x or below x, then ...');
    WriteLn ('IF ... == ...          If the two strings are equal, then ...');
    WriteLn ('MD/MKDIR ...           Create a new directory.');
    WriteLn ('PATH ...               Set or show the PATH.');
    WriteLn ('PAUSE [...]            Wait for a keystroke.');
    WriteLn;
    Pause;
    WriteLn;
    WriteLn ('PROMPT ...             Change the DOS prompt.');
    WriteLn ('REM ...                Remark (Note: The first remark is placed at the');
    WriteLn ('                       beginning of the .COM program, so it is displayed');
    WriteLn ('                       when you TYPE the program).');
    WriteLn ('RD/RMDIR ...           Remove a directory.');
    WriteLn ('REN/RENAME ...         Rename a file or a group of files.');
    WriteLn ('SET [var=[value]]      Set an environment variable (Note: All variables');
    WriteLn ('                       are restored after running the program).');
    WriteLn ('SHIFT                  Move all parameters (%1, %2, ..) one place back.');
    WriteLn ('TYPE ...               Show the contents of a file.');
    WriteLn ('VER                    Show the current DOS version.');
    WriteLn ('VERIFY [on | off]      Set VERIFY on or off.');
    WriteLn ('VOL ...                Show the volume of a drive.');
    WriteLn;
    WriteLn ('Special characters (for the commands ECHO, PAUSE, IF and SET):');
    WriteLn;
    WriteLn ('$g    ">"              $q    "="                $s    <Space>');
    WriteLn ('$l    "<"              $h    <BackSpace>        $e    <Esc>');
    WriteLn ('$b    "|"              $_    <CR/LF>            $$    "$"');
    WriteLn ('$(n)  ASCII number');
    WriteLn;
    WriteLn ('"$" at the end of a line: No <CR>.');
    WriteLn;
    Pause;
    WriteLn;
    WriteLn ('Variables:');
    WriteLn;
    WriteLn ('Besides the environment variables you may also define up to 100');
    WriteLn ('32-bit variables to work with numbers. You can set these variables to');
    WriteLn ('integer numbers in the range -2147483648...+2147483647.');
    WriteLn;
    WriteLn ('Variable commands:');
    WriteLn;
    WriteLn ('VAR varname [=number]   Define a new variable (if no number is specified');
    WriteLn ('                        the variable is set to 0).');
    WriteLn ('LET var = number        Set the variable to a new value.');
    WriteLn ('LET var1 = var2         Copy the value of var2 into var1.');
    WriteLn ('LET var = %1            If %1 is not a valid number, the ERRORLEVEL is set');
    WriteLn ('                        to the position of the error.');
    WriteLn ('LET var = ERRORLEVEL    Sets var to the current errorlevel.');
    WriteLn ('ADD var, x              Add the value of x to var.');
    WriteLn ('SUB var, x              Subtract the value of x from var.');
    WriteLn ('NEG var                 Change the sign of var (+/-).');
    WriteLn ('ABS var                 If var < 0 then the sign is changed.');
    WriteLn ('MUL var, x              Multiply var with x.');
    WriteLn ('DIV var, x              Integer division.');
    WriteLn;
    WriteLn;
    Pause;
    WriteLn;
    WriteLn ('Writing variable numbers:');
    WriteLn;
    WriteLn ('ECHO ... %VAR% ...      Show the number of VAR (decimal).');
    WriteLn ('ECHO %VAR:10%           Use 10 spaces for the number (like this: "       123").');
    WriteLn ('ECHO %VAR:-10%          Spaces after the number ("123       ").');
    WriteLn ('ECHO %VAR:010%          Use "0" instead of spaces ("0000000123").');
    WriteLn ('ECHO %VAR:b%            Show the binary value ("1111011").');
    WriteLn ('ECHO %VAR:X%            Show the hexadecimal value ("7B").');
    WriteLn ('ECHO %VAR:x%            The same, but use lowercase letters ("7b").');
    WriteLn ('ECHO %VAR:o%            Show the octal value (173).');
    WriteLn;
    WriteLn ('Comparing variables:');
    WriteLn;
    WriteLn ('IF %var1% = %var2% ...  If the two variables are the same then ...');
    WriteLn ('IF %var1% <> %var2% ..  If the variables are different then ...');
    WriteLn ('IF %var1% > %var2% ...  If var1 is larger than var2 then ...');
    WriteLn ('IF %var1% < %var2% ...  If var1 is smaller than var2 then ...');
    WriteLn ('IF %var1% >= %var2% ..  If var1 is larger than or equal to var2 then ...');
    WriteLn ('IF %var1% <= %var2% ..  If var1 is smaller than or equal to var2 then ...');
    WriteLn;
    WriteLn ('- You may always insert the word NOT to reverse the condition.');
    WriteLn ('- If you compare strings with <, >, <= or >=, first the length is compared.');
    WriteLn;
    Pause;
    WriteLn;
    WriteLn ('GOSUB and RETURN:');
    WriteLn;
    WriteLn ('You can create subroutines in your programs by using these commands.');
    WriteLn ('Example:');
    WriteLn;
    WriteLn ('   GoTo Start');
    WriteLn ('   :Proc1');
    WriteLn ('   ...');
    WriteLn ('   Return');
    WriteLn ('   :Start');
    WriteLn ('   ...');
    WriteLn ('   GoSub Proc1');
    WriteLn ('   ...');
    WriteLn ('   GoSub Proc1');
    WriteLn;
    WriteLn;
    WriteLn ('You can run the same procedure as often as you like without having to');
    WriteLn ('write it again.');
    WriteLn;
    WriteLn ('NOTE:  Never go to a subroutine using the GOTO command.');
    WriteLn ('       RETURN without GOSUB could cause the system to crach.');
    WriteLn;
    WriteLn;
    Pause;
    WriteLn;
    WriteLn ('Other commands:');
    WriteLn;
    WriteLn ('CRT              After this command all the output to screen is written');
    WriteLn ('                 directly to the video buffer.');
    WriteLn ('DOS              Use DOS routines to handle output to screen.');
    WriteLn ('SETCOLOR n       Change the attribute. Only if CRT procedures are installed.');
    WriteLn ('                 (valid attributes are 0..255 or $00..$FF)');
    WriteLn ('MOVETO x, y      Change the position of the cursor.');
    WriteLn ('SETWINDOW x1,    Define a window (Use this command before CLS, FILLWINDOW,');
    WriteLn ('  y1, x2, y2     FRAMEWIN, MENU, SCROLL). Default: 1, 1, 80, 25.');
    WriteLn ('SCROLL n         Scroll the current window n lines up (or down: n < 0).');
    WriteLn ('FRAMEWINDOW      Draw a frame in the current window.  Chars is either');
    WriteLn ('  chars, title   DOUBLEFRAME or SINGLEFRAME or the characters to be used');
    WriteLn ('                 in the frame, eg. ÉÍ»ººÈͼ.  Title is any text.');
    WriteLn ('FILLWINDOW n     Fills the window with one character (n = 0..255)');
    WriteLn ('CHECKANSI        Set the errorlevel to 1 if ANSI.SYS is installed.');
    WriteLn ('GETSCREEN        Save the contents of the entire screen in memory.');
    WriteLn ('PUTSCREEN        Restores the last screen saved by GETSCREEN or LOADSCREEN');
    WriteLn ('SAVESCREEN file  Save a screen to the disk.');
    WriteLn ('LOADSCREEN file  Load a screen from the disk into memory (use PUTSCREEN to');
    WriteLn ('                 display it).');
    WriteLn ('COUNTPARAMS      Set the errorlevel to the number of parameters.');
    WriteLn;
    Pause;
    WriteLn;
    WriteLn ('Menus:');
    WriteLn;
    WriteLn ('MENU [c1,] [c2,] [c3,] "[" ~O~ption1 "/" O~p~tion2 [/...] "]" [";"]');
    WriteLn;
    WriteLn ('    c1           Attribute of highlighted bar.');
    WriteLn ('    c2           Attribute of hot keys.');
    WriteLn ('    c3           Attribute of hot key in highlighted bar.');
    WriteLn ('    ~X~          Hot key.');
    WriteLn ('    ";"          Return if the user presses <-- or --> (errorlevel 254, 255).');
    WriteLn;
    WriteLn ('If the user presses a hot key or <Enter>, the errorlevel will be set to the');
    WriteLn ('number of the option. If <Esc> is pressed the errorlevel is set to 0.');
    WriteLn ('Example:');
    WriteLn;
    WriteLn ('    Cls');
    WriteLn ('    SetWindow 10, 5, 20, 9');
    WriteLn ('    FrameWindow SingleFrame, Menu ');
    WriteLn ('    SetWindow 11, 6, 19, 8');
    WriteLn ('    Menu $70, $0F, $70, [ ~E~dit / ~R~un / ~Q~uit ]');
    WriteLn ('    if ErrorLevel 3 GoTo Quit');
    WriteLn ('    if ErrorLevel 2 GoTo Run');
    WriteLn ('    ...');
    WriteLn;
    Pause;
    WriteLn;
    WriteLn ('Keyboard commands:');
    WriteLn;
    WriteLn ('ASK ["prompt"], keylist     Set the errorlevel to the position in the list.');
    WriteLn ('ASKYN ["prompt"]            Yes: errorlevel = 1, No errorlevel = 0.');
    WriteLn ('GETKEY                      Set the errorlevel to the ASCII value of a');
    WriteLn ('                            keystroke.');
    WriteLn ('GETKBFLAGS                  Set the errorlevel to the keyboard flags byte.');
    WriteLn ('SETKBFLAGS <var>            Change the keyboard flags.');
    WriteLn ('SETBIT n <var>              Set bit n of <var> to 1.');
    WriteLn ('RESETBIT n <var>            Set bit n of <var> to 0.');
    WriteLn ('GETBIT n <var>              Set the errorlevel to the value of bit n of <var>.');
    WriteLn;
    WriteLn ('Keyboard flag bits:');
    WriteLn;
    WriteLn ('76543210');
    WriteLn ('.......1      Right Shift key pressed');
    WriteLn ('......1.      Left Shift key pressed');
    WriteLn ('.....1..      Ctrl key pressed');
    WriteLn ('....1...      Alt key pressed');
    WriteLn ('...1....      ScrollLock on');
    WriteLn ('..1.....      NumLock on');
    WriteLn ('.1......      CapsLock on');
    WriteLn ('1.......      Insert mode on');
    WriteLn;
    Pause;
    WriteLn;
    WriteLn ('INPUT <Env-var>      Input any environment variable (from the keyboard).');
    WriteLn ('GETX <var>           Store the cursor position in a variable.');
    WriteLn ('GETY <var>           Store the cursor line in a variable.');
    WriteLn ('GETCURSOR <var>      Store the cursor size in a variable.');
    WriteLn ('SETCURSOR <var>      Set the size of the cursor (Default $0B0C,');
    WriteLn ('                     Block cursor: $001F, No cursor: $1F00).');
    WriteLn ('DISKFREE <var>       Get the free space on a disk into a variable.');
    WriteLn ('UPPERCASE <env-var>  Change all letters in a variable to capitals.');
    WriteLn ('LOWERCASE <env-var>  Change the capitals into lowercase letters.');
    WriteLn ('GETDRIVE <env-var>   Set an environment variable to the current drive.');
    WriteLn ('GETDIR <env-var>     Set a variable to the current directory.');
    WriteLn ('GETDAY <env-var>     Set a variable to the day of the week.');
    WriteLn ('GETDATE <env-var>    Set a variable to the current date.');
    WriteLn ('GETTIME <env-var>    Set a variable to the current time.');
    WriteLn ('GETLENGTH <env-var>  Set the errorlevel to the length of the var.');
    WriteLn ('CHECKERRORS ON|off   if on the program will stop and ask the user.');
    WriteLn ('                     wether to continue or not. If off, the');
    WriteLn ('                     error number is stored in the ERRORLEVEL.');
    WriteLn ('Example:');
    WriteLn;
    WriteLn ('   CheckErrors OFF');
    WriteLn ('   ChDir %1');
    WriteLn ('   if ErrorLevel 1 Echo THERE IS NO DIRECTORY NAMED "%1".');
    WriteLn;
    Pause;
    WriteLn;
    WriteLn ('BEEP                Make a short sound.');
    WriteLn ('IF KEYPRESSED ...   If the user has pressed any key on the keyboard then ...');
    WriteLn ('GETRANDOM           Set the errorlevel to a random number (0..255).');
    WriteLn ('WRITECHAR n1 [,n2]  Write 1 (or n2) character(s) with ASCII code n1.');
    WriteLn ('INLINE n1, n2, ...  Use machine language in your programs (Hex numbers only).');
    WriteLn;
    WriteLn ('Example:');
    WriteLn;
    WriteLn ('    REM This will print the screen (int 5):');
    WriteLn ('    INLINE cd 05');
    WriteLn;
    WriteLn ('An INLINE procedure may destroy the values of the registers AX, BX, CX, DX,');
    WriteLn ('SI, DI and BP. The other registers must be restored.');
    WriteLn;
    WriteLn ('There are two ways to run any program:');
    WriteLn ('- Type only the name. A copy of COMMAND.COM is loaded and searches all');
    WriteLn ('  directories of the PATH for the program. If the program is not found,');
    WriteLn ('  you will get the message "Bad command or filename".');
    WriteLn ('- Type the full pathname and extension ("C:\UTIL\BC.EXE"). Use this');
    WriteLn ('  method if you want to know what errorlevel is left by the program.');
    WriteLn;
    WriteLn ('                --  e-mail: mike@wieringsoftware.nl  --');
    WriteLn;
    Halt(0);
  end;

end.