NSIS-尝试比较两个字符串时出错

Question

I'm trying to compare a string with a variable with have exactly the same value and isn't working.
The flow is:
1. Open a file that has just one line of Node.Js version;
2. Read the line and save into $NODE_VERSION
3. Close file
4. Check if $NODE_VERSION is equal "v8.11.3" -- and this always returns false.

I had already:
1. Create another variable and set in hardcoded the same values for both and compare.
2. Compare the $NODE_VERSION with the string "v8.11.3"
3. Compare "1" = "1" and works.
4. Use If/EndIf
5. Use StrCmp

Var /GLOBAL NODE_VERSION<br/>
Function .onInit<br/>
  ExecWait "node --version > C:\Windows\nodeversion.txt"<br/>
  ClearErrors<br/>
  FileOpen $0 "C:\Windows\nodeversion.txt" r<br/>
  IfErrors done<br/>
  FileRead $0 $NODE_VERSION<br/>
  FileClose $0<br/>
  StrCmp $NODE_VERSION "v8.11.3" 0 nobla<br/>
       Messagebox MB_OK "not true, or maybe"<br/>
  nobla:<br/>
 Messagebox MB_OK "not true"<br/>
 Messagebox MB_OK $NODE_VERSION<br/>

  ${If} $NODE_VERSION == "v8.11.3"<br/>
    Call uninstallNode<br/>
    Goto FinishInit<br/>
  ${EndIf}<br/>

I want to get into a true statement

Answer 1

FileRead includes newline-characters in the returned string and you must remove them when you are looking for a exact string match.

!include "LogicLib.nsh"
!include "StrFunc.nsh"
${StrTrimNewLines} ; Tell StrFunc.nsh to define this function for us

Section
FileOpen $0 "$windir\nodeversion.txt" r
FileRead $0 $1
${StrTrimNewLines} $1 $1
FileClose $0
MessageBox mb_ok "Line 1=|$1|"
${If} "v8.11.3" == "$1"
  ; ...
${EndIf}
SectionEnd