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inno-setuppascalscript

Parsing output of wmic in Inno Setup

I have recently used Inno Setup for my Java software. I am writing a function to check whether a printer driver exists by calling wmic printer get name /All and reading it output. But the problem is when I am reading the text file and check if it contains a specific substring by Pos(), it always returning 0, but when I tried to test with a character it returned the true value. I'm currently using version 5.6.1 Unicode.

I have looked at Delphi Pos always returning 0 but I think it's not my case:

Here is how I did it:

function isContainedInFile(File, Substring: String): Boolean;
var 
  Lines: TArrayOfString;
  i: Integer;
  line: String;
begin
  Substring := Uppercase(Substring);
  Result := False;
  if LoadStringsFromFile(File, Lines) then 
     begin
        for i:= 0 to GetArrayLength(Lines) - 1 do
          begin
            line := Lines[i];
            if (Length(line) = 0) then
                continue;

            line := Uppercase(Trim(line));
            Log('Substring:' + Substring + ', Line:' + line + ', Pos:' + IntToStr(Pos(Substring, line)));
            if (Pos(Substring, line) <> 0) then
            begin
                Result:= True;
                break;
            end;
          end;
     end;
end;

This is how I called the isContainedInFile():

function IsBrotherDriverInstalled(): Boolean;
var
  path, brotherPath, ListPrinterPath, ListPrinter: String;
  check, index: Integer;
begin       
  ListPrinterPath := ExpandConstant('{tmp}\printerlist.tdm');
  { Save temporarily the list }
  Exec(ExpandConstant('{cmd}'), '/c wmic printer get name /All > "' + ListPrinterPath + '"', 
                      '', SW_HIDE, ewWaitUntilTerminated, check);
  { Check if the list has the printer }
  Result := isContainedInFile(ListPrinterPath, PrinterName);
  { Delete the file }
  DeleteFile(ListPrinterPath);
end;

Here is my output when the substring has length > 1:

Pos returned 0

And when the substring has length = 1:

Pos returned true value

Thanks in advance.

Solution

  • wmic uses UTF-16 encoding in its output. LoadStringsFromFile does not support UTF-16 encoding. See Inno Setup Pascal Script - Reading UTF-16 file.

    So the file is read incorrectly.

    You seem to be using Inno Script Studio IDE. Its Messages console does not print messages accurately, so it obfuscates the real problem. Had you used original Inno Setup Compiler IDE or checked a physical log file, you would see the problem straight away:

    2018-08-26 10:44:35.783   Substring:BROTHER, Line:ÿþN A M E, Pos:0
2018-08-26 10:44:35.783   Substring:BROTHER, Line:, Pos:0
2018-08-26 10:44:35.783   Substring:BROTHER, Line:S E N D   T O   O N E N O T E   2 0 1 6, Pos:0
2018-08-26 10:44:35.783   Substring:BROTHER, Line:, Pos:0
2018-08-26 10:44:35.783   Substring:BROTHER, Line:S A M S U N G   S C X - 3 4 0 0   S E R I E S   ( U S B 0 0 1 ), Pos:0
2018-08-26 10:44:35.783   Substring:BROTHER, Line:, Pos:0
2018-08-26 10:44:35.783   Substring:BROTHER, Line:M S   P U B L I S H E R   C O L O R   P R I N T E R, Pos:0
2018-08-26 10:44:35.783   Substring:BROTHER, Line:, Pos:0
2018-08-26 10:44:35.783   Substring:BROTHER, Line:M I C R O S O F T   X P S   D O C U M E N T   W R I T E R, Pos:0
2018-08-26 10:44:35.783   Substring:BROTHER, Line:, Pos:0
2018-08-26 10:44:35.783   Substring:BROTHER, Line:M I C R O S O F T   P R I N T   T O   P D F, Pos:0
2018-08-26 10:44:35.783   Substring:BROTHER, Line:, Pos:0
2018-08-26 10:44:35.783   Substring:BROTHER, Line:H P   E P R I N T   +   J E T A D V A N T A G E, Pos:0
2018-08-26 10:44:35.783   Substring:BROTHER, Line:, Pos:0
2018-08-26 10:44:35.783   Substring:BROTHER, Line:F A X, Pos:0
2018-08-26 10:44:35.783   Substring:BROTHER, Line:, Pos:0
2018-08-26 10:44:35.783   Substring:BROTHER, Line:, Pos:0

    Solutions: