NSIS get parameter

to get -n 0 value passing as a string (no need option) to the installer, I don't quite understand what this function work?

; GetParameters
 ; input, none
 ; output, top of stack (replaces, with e.g. whatever)
 ; modifies no other variables.

Function GetParameters

  Push $R0
  Push $R1
  Push $R2
  Push $R3

  StrCpy $R2 1
  StrLen $R3 $CMDLINE

  ;Check for quote or space
  StrCpy $R0 $CMDLINE $R2
  StrCmp $R0 '"' 0 +3
    StrCpy $R1 '"'
    Goto loop
  StrCpy $R1 " "

  loop:
    IntOp $R2 $R2 + 1
    StrCpy $R0 $CMDLINE 1 $R2
    StrCmp $R0 $R1 get
    StrCmp $R2 $R3 get
    Goto 开发者_开发知识库loop

  get:
    IntOp $R2 $R2 + 1
    StrCpy $R0 $CMDLINE 1 $R2
    StrCmp $R0 " " get
    StrCpy $R0 $CMDLINE "" $R2

  Pop $R3
  Pop $R2
  Pop $R1
  Exch $R0

FunctionEnd

---

GetParameters just gets the parameters ("yourapp.exe /foo /bar" will give you "/foo /bar" etc) It basically just strips away the first token (with quote handling) Use GetOptions to get the value of a parameter.

!include "FileFunc.nsh"
!include "LogicLib.nsh"

function .onInit
${GetParameters} $0
ClearErrors
${GetOptions} $0 "-n" $1
${IfNot} ${Errors}
    MessageBox mb_ok $1
${EndIf}
functionend