String arrays, sort of

[DrBonzo]

Several times, I've wanted to do the same body of script code, just changing one string. Without some sort of string array, I've just made the body a function and called it several times.

It finally occurred to me, looking at StrStr, that if I just had a special delimiter character, I could get the same effect by separating the string elements with that delimiter. So here's an implementation using "$\n" as the delimiter. I hope someone finds it useful:

-------- PerLine.nsh

code:


!include LogicLib.nsh



;;;;;;;

;

;  global vars for loop

;

var /global PerLineArray

var /global PerLineCount

var /global PerLineChars



!macro _PerLine lineArray loopVar

    StrCpy $PerLineArray ${lineArray}

    StrLen $PerLineChars $PerLineArray

    StrCpy $PerLineCount 1

    ${DoWhile} $PerLineChars > 1

        Push $PerLineArray

        Call leadingLine

        Pop ${loopVar}

        Push $r0

        StrLen $r0 ${loopVar}

        IntOp $r0 $r0 + 1

        StrCpy $PerLineArray $PerLineArray "" $r0

        Pop $r0

        StrLen $PerLineChars $PerLineArray

!macroend

!define PerLine `!insertmacro _PerLine`



;;;;;;;;;;

;

;  usage, for example:

;

;   StrCpy $1 1 ;  line number

;   StrCpy $2 ""    ; accumulating message

;   ${PerLine} "line1$\nline2$\n$line3" $line

;       ;  body does something with $line 3 times

;       StrCpy $2 "$2$\n$1 - $line"

;       IntOp $1 $1 + 1

;   ${Loop}

;   MessageBox MB_OK $2

;



;;;;;;;;;;

;

;  helper function to strip off leading line

;

Function LeadingLine

	 ;  input - top of stack contains string, possibly containing "$\n"

	 ;  output - top of stack contains string up to 1st "$\n"

	 ;  r0 - working copy of input & result

	 ;  r1 - char index

	 ;  r2 - length of input

	 ;  r3 - nth char of input

	 Exch $r0

	 Push $r1

	 Push $r2

	 Push $r3

	 StrCpy $r1 0

	 StrLen $r2 $r0

   _leadLoop:

	 IntCmp $r1 $r2 _leadDone

	 StrCpy $r3 $r0 1 $r1

     StrCmp $r3 "$\n" _leadDone

     IntOp $r1 $r1 + 1

     Goto _leadLoop



   _leadDone:

	 StrCpy $r0 $r0 $r1

	 Pop $r3

	 Pop $r2

	 Pop $r1

	 Exch $r0



FunctionEnd

[Afrow UK]

This is one way but it is much easier (and cleaner) to use a plug-in (such as NSISArray) or use INI files/registry to store multiple values (i.e. by index or value name). You do not need to worry about the delimiter being in your array elements then.

Stu