!include "LogicLib.nsh"

# http://nsis.sourceforge.net/Another_String_Replace_%28and_Slash/BackSlash_Converter%29
#
; Push $filenamestring (e.g. 'c:\this\and\that\filename.htm')
; Push "\"
; Call StrSlash
; Pop $R0
; ;Now $R0 contains 'c:/this/and/that/filename.htm'
Function StrSlash
  Exch $R3 ; $R3 = needle ("\" or "/")
  Exch
  Exch $R1 ; $R1 = String to replacement in (haystack)
  Push $R2 ; Replaced haystack
  Push $R4 ; $R4 = not $R3 ("/" or "\")
  Push $R6
  Push $R7 ; Scratch reg
  StrCpy $R2 ""
  StrLen $R6 $R1
  StrCpy $R4 "\"
  StrCmp $R3 "/" loop
  StrCpy $R4 "/"  
loop:
  StrCpy $R7 $R1 1
  StrCpy $R1 $R1 $R6 1
  StrCmp $R7 $R3 found
  StrCpy $R2 "$R2$R7"
  StrCmp $R1 "" done loop
found:
  StrCpy $R2 "$R2$R4"
  StrCmp $R1 "" done loop
done:
  StrCpy $R3 $R2
  Pop $R7
  Pop $R6
  Pop $R4
  Pop $R2
  Pop $R1
  Exch $R3
FunctionEnd


# http://nsis.sourceforge.net/StrStr
#
!define StrStr "!insertmacro StrStr"
 
!macro StrStr ResultVar String SubString
  Push `${String}`
  Push `${SubString}`
  Call StrStr
  Pop `${ResultVar}`
!macroend
 
Function StrStr
/*After this point:
  ------------------------------------------
  $R0 = SubString (input)
  $R1 = String (input)
  $R2 = SubStringLen (temp)
  $R3 = StrLen (temp)
  $R4 = StartCharPos (temp)
  $R5 = TempStr (temp)*/
 
  ;Get input from user
  Exch $R0
  Exch
  Exch $R1
  Push $R2
  Push $R3
  Push $R4
  Push $R5
 
  ;Get "String" and "SubString" length
  StrLen $R2 $R0
  StrLen $R3 $R1
  ;Start "StartCharPos" counter
  StrCpy $R4 0
 
  ;Loop until "SubString" is found or "String" reaches its end
  ${Do}
    ;Remove everything before and after the searched part ("TempStr")
    StrCpy $R5 $R1 $R2 $R4
 
    ;Compare "TempStr" with "SubString"
    ${IfThen} $R5 == $R0 ${|} ${ExitDo} ${|}
    ;If not "SubString", this could be "String"'s end
    ${IfThen} $R4 >= $R3 ${|} ${ExitDo} ${|}
    ;If not, continue the loop
    IntOp $R4 $R4 + 1
  ${Loop}
 
/*After this point:
  ------------------------------------------
  $R0 = ResultVar (output)*/
 
  ;Remove part before "SubString" on "String" (if there has one)
  StrCpy $R0 $R1 `` $R4
 
  ;Return output to user
  Pop $R5
  Pop $R4
  Pop $R3
  Pop $R2
  Pop $R1
  Exch $R0
FunctionEnd