Could you help me change this into a bash script?

[jasong]

The following is a script used for a project called '3x+1' which is studying the Collatz Conjecture. It is a .vbs script.

What I'd like to be able to do is turn it into a script that can be run under a bash prompt that calls on Wine to run the Windows executable.

What the program basically does is take the range given it, which is from the 'Const blockstart' number to that number plus the 'Const blockinterval' number. Basically, these numbers multiplied by 10^12 are considered to be the range.

These numbers are changed to whatever is needed by the user. When the script is run, it looks for a log file to see if the program's been run previously. If it has, then it just starts the next "chunk" in that range. A chunk is basically a range of numbers from one multiple of 2^34 to the next multiple of 2^34. Technically, though the ranges are reserved in multiples of 10^12, they are completed in ranges of 2^34. Not sure if the rounding at the very beginning is always to the nearest multiple of 2^34, rounded up, or rounded down. It's in the script somewhere.

The main goal of this script is to (1)determine what needs to be completed, (2) add the normal arguments to the script: idle process, a special command to make sure it's started properly, tell it what it needs to start at and where it needs to end(which is described as how many chunks need to be completed), and I'm not sure what else. (3) Lastly, it needs to send out the command, which in this case involves Wine.

Any help is appreciated. (Even pseudocode that classifies the stuff in the .vbs script in such a way that Googling for the solution gets tremendously easier.

I do want to become a computer programmer, but in this case the learning curve is a bit steep.

option explicit



' ---- Change this constant for a new block! ----

Const blockstart = 58860

Const blockinterval = 20

' --------------------------------------



Const exefilename = "w422f.exe"



dim NTSystem, shell, fso, cmdfilename, logfilename



On Error Resume Next



set shell = wscript.createobject("wscript.shell")

set fso = wscript.createobject("scripting.filesystemobject")

logfilename = "w" & cstr(blockstart) & ".log"



NTSystem = RunningOnNT 

If NTSystem Then

  cmdfilename = "wondrous.cmd"

Else

  cmdfilename = "wondrous.bat"

End If



makecmdfile NTSystem

If err.Number <> 0 then

  msgbox err.description, vbexclamation, wscript.scriptname

else

  shell.run cmdfilename

end if



wscript.quit



'------------------------------

Sub makecmdfile(Byval NTSystem) 



dim ts

dim i, ch, lastline, s1, s2, s3

dim start, finish

dim startcount, finishcount, loopcount

dim Message, procspeed, calcdays



On error resume next

set ts = fso.opentextfile(logfilename)

if err <> 0 then   ' -- New block, start from scratch

  start = blockstart & "000000000000"

  If not NTSystem Then

    Message = "Warning: you are starting the program on a non-NT system." & VBNewLine

    Message = Message & "Since the program can not be started in idle priority" & VbNewLine

    Message = Message & "performance of normal applications on your system could be affected" 

    Message = Message & " (this message wil disappear automatically in 60 seconds)" 

    Shell.Popup Message, 60, "Class Record Search", VBExclamation

  End If

  ShowDuration 

else               ' -- Read last number from file

  do

    s1 = ts.readline

    If Len(Trim(s1)) > 0 Then

      lastline = s1

    End If

  loop until ts.atendofstream

  s2 = ""

  for i = 1 to len(lastline)

    ch = mid(lastline,i,1)

    if isnumeric (ch) then

      s2 = s2 & ch

    end if

    if not isnumeric(ch) and ch <> "," and len(s2) > 0 then

      exit for

    end if

  next 

  ts.close

  start = s2

end if

on error goto 0



  ' ---- Calculate new loopcount

finish = (clng(blockstart) + clng(blockinterval) ) * 1.0e+12

startcount  = int( cdbl(start ) / (2.0^32) )

finishcount = int( cdbl(finish) / (2.0^32) )

loopcount = finishcount - startcount + 2



  ' ---- Create batchfile

set ts = fso.createtextfile(cmdfilename, True)

if loopcount > 0 then

  s3 = "start /min "

  If NTSystem Then

    s3 = s3 & " /low " 

  End If

  s3 = s3 & exefilename & " /o /c" & cstr(loopcount) & " /f" & logfilename & " " & start

  ts.writeline s3

end if

ts.close



end sub



Function RunningOnNT

  Dim NTVersionKey, v

  NTVersionKey = "HKLM\Software\Microsoft\Windows NT\CurrentVersion\CurrentVersion"

  On Error Resume Next

  Err.Clear

  v = shell.RegRead(NTVersionKey)

  RunningOnNT = (Err.Number = 0)

End Function



Sub ShowDuration

  ' -- Show info about length of calculation

  Dim Message, procspeed, calcdays

  On Error Resume Next

  procspeed = shell.regread("HKLM\hardware\description\system\centralprocessor\0\~Mhz")  

  If Err.Number = 0 then

    calcdays = cint (920.0 * blockinterval / procspeed)

    Message = "Calculation time on this machine will probably take around "

    Message = Message & calcdays & " days" & vbNewLine

    Message = Message & " (this message wil disappear automatically in 30 seconds)" 

    Shell.PopUp Message, 30, "Class Record Search", VBInformation

  Else

    Err.Clear

  End if

End Sub



' ---- end of script ----

[Ken_g6]

Well, this chunk:

' -- Read last number from file

  do

    s1 = ts.readline

    If Len(Trim(s1)) > 0 Then

      lastline = s1

    End If

  loop until ts.atendofstream

  s2 = ""

  for i = 1 to len(lastline)

    ch = mid(lastline,i,1)

    if isnumeric (ch) then

      s2 = s2 & ch

    end if

    if not isnumeric(ch) and ch <> "," and len(s2) > 0 then

      exit for

    end if

  next 

  ts.close

  start = s2

looks to be equivalent to:

start = `tail -1 $logfilename | sed -e "s/^[^0-9,]*//;s/[^0-9,].*$//;s/,//g"`

Ain't regular expressions grand?

Of course, with the amount of math done in other places, you might want to use a different scripting language instead. Might I suggest Perl, where I believe that line would work almost identically? In Perl:

$start = `tail -1 $logfilename`;
$start =~ s/^[^0-9,]*//;
$start =~ s/[^0-9,].*$//;
$start =~ s/,//g";

is even better, since sed (Perl's older brother) isn't used.