使用NSIS安装软件时，如何通过从目标文件夹获取路径来检查驱动器中的空间

Question

How to check the space in the drive by taking the path from the Destination Folder When installing the software.

I am able to check the space of the specific drive (for eg, "C") using the below code snippet.

But I want to take the drive or path from the Destination folder dynamically and check the space of the drive whether there is enough space or not.

!define sysGetDiskFreeSpaceEx 'kernel32::GetDiskFreeSpaceExA(t, *l, *l, *l) i'    
function CheckSpaceFunc
      IntCmp $2 0 ignorequota
      ; obey quota
      System::Call '${sysGetDiskFreeSpaceEx}(r1,.r2,,.)'
      goto converttokb
      ; ignore quota
      ignorequota:
      System::Call '${sysGetDiskFreeSpaceEx}(r1,.,,.r2)'
      converttokb:
      ; convert the large integer byte values into managable kb
      System::Int64Op $2 / 1024
      Pop $2
      ; check space
      System::Int64Op $2 > $0
      Pop $2
    functionend


    Section "TestApp"

      SectionIn RO


      StrCpy $0 40000 ; kb u need
      StrCpy $1 'c:' ; check drive c: for space
      Call CheckSpaceFunc
      IntCmp $2 1 okay
      MessageBox MB_OK "Error: Not enough disk space"
      okay:

    SectionEnd

Could anyone please help me

Answer 1

The built-in directory page ( Page Directory or !insertmacro MUI_PAGE_DIRECTORY ) will perform the free space check for you and takes care of all the details.

It might be tempting to just do StrCpy $1 $InstDir 3 to get the drive letter and perform the check yourself but this can give you the wrong result because NTFS supports mounting other volumes as a folder .

GetDiskFreeSpaceEx does support directory paths but I believe the path has to exist so if you want to use $InstDir before $InstDir has been created then you must chop off subfolders until GetDiskFreeSpaceEx succeeds (or you only have a invalid drive letter left of the path).

Your !define should also be changed from GetDiskFreeSpaceExA to GetDiskFreeSpaceEx because it uses the t string type. This will make it Unicode compatible.