Copyright © 2003- by Prof. Timo Salmi  
Last modified Sat 28-Jan-2017 21:03:30

Assorted NT/2000/XP/.. CMD.EXE Script Tricks
From the html version of the tscmd.zip 1cmdfaq.txt file
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This page is edited from the 1cmdfaq.txt faq-file contained in my tscmd.zip command line interface (CLI) collection. That zipped file has much additional material, including a number of detached .cmd script files. It is recommended that you also get the zipped version as a companion.

Please see "The Description and the Index page" for the conditions of usage and other such information.

61} How can one devise a command line calculator?

There are several options. A fairly trivial, but severely limited option is using the SET /A command. For example
  @echo off & setlocal enableextensions
  set /a x=4+7
  echo %x%
  endlocal & goto :EOF

The output would be

A second option is using G(nu)AWK. For example
  @echo off & setlocal enableextensions
  gawk 'BEGIN{printf"%%s\n",4/7}'
  endlocal & goto :EOF

The output would be
This option could be used to perform quite complicated calculations.

Of course, one could also have
  @echo off & setlocal enableextensions
  set find_=gawk.exe
  set found_=
  for %%f in ("%find_%") do set found_="%%~$PATH:f"
  if exist "%find_%" set found_="%find_%"
  if [%found_%]==[""] (
    echo "%find_%" not found at path or in the current folder
    goto :EOF)
  if not "%~1"=="" goto _calculate
  echo Usage: %~0 Expression
  goto :EOF
  gawk 'BEGIN{printf"%%s\n",%*}'
  endlocal & goto :EOF
or much more fully:
  @echo off & setlocal enableextensions
  if "%~1"=="" (call :ProgramTitle & call :ProgramHelp & goto _out)
  if "%~1"=="?" (call :ProgramTitle & call :ProgramHelp & goto _out)
  if "%~1"=="/?" (call :ProgramTitle & call :ProgramHelp & goto _out)
  set gawk_=GAWK.EXE
  set unxgawk_=UNXGAWK.EXE
  set found1_=
  for %%f in ("%gawk_%") do set found1_="%%~$PATH:f"
  if exist "%gawk_%" set found1_="%gawk_%"
  set found2_=
  for %%f in ("%unxgawk_%") do set found2_="%%~$PATH:f"
  if exist "%unxgawk_%" set found2_="%unxgawk_%"
  if [%found1_%]==[""] if [%found2_%]==[""] (
    call :ProgramTitle
    echo Neither %gawk_% nor %unxgawk_% found at path or in the current folder
    goto _out)
  "%gawk_%" 'BEGIN{srand();pi=3.14159265358979;printf"%%.15g\n",%*}'
  "%unxgawk_%" "BEGIN{srand();pi=3.14159265358979;printf\"%%.15g\n\",%*}"
  goto _out
  echo +-----------------------------------------------------+
  echo ^ GA.CMD Use gawk and unxgawk to perform calculations ^
  echo ^ By Prof. Timo Salmi. Last modified Wed 26-Jan-2011  ^
  echo +-----------------------------------------------------+
  goto :EOF
  echo Usage: GA Expression
  echo Examples:                          Result
  echo  GA 4 / 7 * 2.5                    1.42857142857143
  echo  GA sqrt(2)                        1.4142135623731
  echo  GA 2**4                           16
  echo  GA exp(4*log(2))                  16
  echo  GA 103 %% 10                      3
  echo  GA exp(1)                         2.71828182845905
  echo  GA log(10)                        2.30258509299405
  echo  GA sin(45*pi/180)                 0.707106781186547
  echo  GA rand()                         0.582076438973693 (e.g.)
  echo  GA int((50-10+1)*rand()+10)       [A random integer 10...50]
  echo  GA strtonum(0xFE)                 254 (unxgawk only)
  echo  GA strtonum(0376)                 254 (unxgawk only)
  echo Further options on the command line:
  echo  Dec to Hex: unxgawk "BEGIN{printf\"%%X\n\",254}"
  echo  Dec to Oct: unxgawk "BEGIN{printf\"%%o\n\",254}"
  echo  Date: unxgawk "BEGIN{printf\"%%s\n\",strftime(\"%%Y%%m%%d %%H%%M%%S\",systime())}"
  goto :EOF
  if not defined cmdbox if defined PauseIfFromDesktop pause
  endlocal & goto :EOF

A third option is using a third-party program such as FN.EXE from tsfunc17.zip (or whatever is the current version number). An example
  D:\TEST>fn sin(45*3.1415926536/180) /b

A fourth option is using QBASIC or GWBASIC, if available. For more see
  FU.BAT Poor man's function evaluator
and the MS-DOS+Win../95/98/ME FAQ tsbat.zip item "141. Can I calculate factorials in a batch? Do I need recursion?" which is sufficiently compatible with NT/2000/XP.

A fifth option is letting the CMD.EXE script build a Visual Basic Script (VBScript)
  @echo off & setlocal enableextensions
  :: Usage

  set help_=
  if "%~1"=="" set help_=true
  if "%~1"=="?" set help_=true
  if "%~1"=="/?" set help_=true
  if defined help_ (
    echo ^| CA.CMD Perform Visual Basic calculations          ^|
    echo ^|        in the XP command line window              ^|
    echo ^| By Prof. Timo Salmi, Last modified Tue 3-Jun-2008 ^|
    echo +---------------------------------------------------+
    echo Usage: %~f0 Expression
    echo.                                       Result
    echo Examples: CA 4 / 7 * 2.5               1.42857142857143
    echo           CA Round^(Sqr^(2^),3^)       1.414
    echo           CA 2^^^^4                    16 [Note the need of double carets ^^]
    echo           CA 103 Mod 10                3
    echo           CA 103 \ 10                  10
    echo           CA Exp^(1^)                  2.71828182845905
    echo           CA Log^(10^)                 2.30258509299405
    echo           CA Sin^(45*Pi/180^)          0.707106781186547
    echo           CA CDbl^(Rnd^)               0.575344264507294
    echo           CA Int^(^(50-10+1^)*Rnd+10^) [A random integer 10...50]
    echo           CA Hex^(254^)                FE
    echo           CA Oct^(254^)                376
    echo           CA 20/4=5                    -1 ^(i.e. true^)
    echo           CA Date-1                    Date yesterday
    if not defined cmdbox if defined PauseIfFromDesktop pause
    goto :EOF)
  :: File paths

  set temp_=%temp%
  if defined mytemp set temp_=%mytemp%
  if not exist "%temp_%\" (
    echo Working folder %temp_% not found
    echo You may have to recreate it
    goto :EOF
  set vbscalc_=%temp_%\vbscalc.vbs
  set result_=%temp_%\result.txt
  :: Build a Visual Basic Script

  echo Randomize>"%vbscalc_%"
  echo Const pi=3.14159265358979>>"%vbscalc_%"
  echo WScript.Echo Eval("%*")>>"%vbscalc_%"
  :: Run it with Microsoft Windows Script Host Version 5.6

  cscript //nologo "%vbscalc_%">"%result_%"
  :: The result from the optional output file

  type "%result_%"
  for %%f in ("%vbscalc_%" "%result_%") do (
    if exist %%f del %%f)
  endlocal & goto :EOF

The other input/output options include e.g.
  C:\_D\TEST>CA Year(Now)

  C:\_D\TEST>CA Month(Now)

  C:\_D\TEST>CA Day(Now)

  C:\_D\TEST>CA Weekay(Now)
  2 (Stands for Monday)

  C:\_D\TEST>CA WeekDayName(Weekday(Now), True)
  Mon (The True stands for abbreviate)

  C:\_D\TEST>CA Chr(60)

  C:\_D\TEST>CA Asc("a")
  C:\_M\TEMP\vbscalc.vbs(3, 25) Microsoft VBScript compilation error: Expected ')'

As you can observe the case of trying to return the ANSI character code corresponding to the first letter in a string produces an error. However, we can easily write a simple special solution to get the codes:
  @echo off & setlocal enableextensions
  >"%temp%\tmp$$$.vbs" echo WScript.Echo Asc("%~1")
  cscript //nologo "%temp%\tmp$$$.vbs"
  for %%f in ("%temp%\tmp$$$.vbs") do if exist %%f del %%f
  endlocal & goto :EOF

The output could be e.g.

References/Comments: (If a Google message link fails try the links within the brackets.)
  Google Groups Mar 24 2004, 2:34 am [M]
  Google Groups Apr 27 2010, 8:12 pm [M]
  Number converter - hex, octal, binary | Coder’s Toolbox