IsEmptyDir check - NSIS Forums

PoRtAbLe_StEaLtH
16th January 2013 11:55 UTC

IsEmptyDir check
Im not an expert .. but find NSIS an intriguing language.
I love the simplicity, and small overhead.

I discover new things everyday.

For instance.. today.. i learned:

IfFileExists 

>

if used with a wildcard to detect if files exists, will always return true, due to ".", "..".

Example:


IfFileExists `$INSTDIR\Dir\*.*` 0 skip

     MessageBox MB_OK "Did not skip."

>skip:

Using Logic:

${If} ${FileExists} `$INSTDIR\Dir\*.*`

    MessageBox MB_OK "Did not skip."

>${EndIf}

Both examples will execute MessageBox, because it will detect ".", "..".

I have put together a useful script that will allow both above examples to work.

;!include logiclib.nsh


>!define IsEmptyDir `"" LL_IsEmptyDir`

!macro _LL_IsEmptyDir _a _b _t _f

   !insertmacro _LOGICLIB_TEMP

   ${EmptyDir} `${_b}` $_LOGICLIB_TEMP

   !insertmacro _= $_LOGICLIB_TEMP 1 `${_t}` `${_f}`

!macroend

>!macro EmptyDir _DIR _VAR

    Push${_DIR}

    Call EmptyDir

    Pop${_VAR}

!macroend

>!define EmptyDir `!insertmacro EmptyDir`

Function EmptyDir

>; renamed isempty from:

;http://nsis.sourceforge.net/Check_if_dir_is_empty

  # Stack ->                    # Stack: <directory>

 Exch $0                       # Stack: $0

 Push $1                       # Stack: $1, $0

 FindFirst $0 $1 "$0\*.*"

 strcmp $1 "." 0 _notempty

    FindNext$0 $1

    strcmp$1 ".." 0 _notempty

      ClearErrors

      FindNext$0 $1

      IfErrors 0 _notempty

        FindClose$0

        Pop$1                  # Stack: $0

       StrCpy $0 1

        Exch$0                 # Stack: 1 (true)

        goto _end

     _notempty:

      FindClose $0

       ClearErrors

       Pop$1                   # Stack: $0

      StrCpy $0 0

       Exch$0                  # Stack: 0 (false)

 _end:

>FunctionEnd 

>

Now you can do this:


`

    MessageBox MB_OK "Did not skip."

>${EndIf}

im sure the script can be shortened/improved..
But im not an expert..
infact.. i would truly love it if someone could improve the "isEmptyDir" script w/ Logic.

gfm688
16th January 2013 13:29 UTC

System::Call Shlwapi::PathIsDirectoryEmpty(t"$INSTDIR\Dir")i.r0
StrCmp $0 1 0 +2
MessageBox MB_OK "Directory is empty"

PoRtAbLe_StEaLtH
16th January 2013 13:48 UTC

Amazing

Originally posted by gfm688
System::Call Shlwapi::PathIsDirectoryEmpty(t"$INSTDIR\Dir")i.r0
StrCmp $0 1 0 +2
MessageBox MB_OK "Directory is empty"

Amazing. :up:

all of that code can now be shrunken to this:

!define IsEmptyDir `"" LL_IsEmptyDir`

!macro _LL_IsEmptyDir _a _b _t _f

   !insertmacro _LOGICLIB_TEMP

         System::Call Shlwapi::PathIsDirectoryEmpty(t"${_b}")i.r0 $_LOGICLIB_TEMP

   !insertmacro _= $_LOGICLIB_TEMP 1 `${_t}` `${_f}`

!macroend 

>

to call:


nsh


>${IfNot} ${IsEmptyDir} `$Dir_to_check`

     "code to execute"

>${EndIf}

Thank you gfm688.

gfm688
17th January 2013 01:28 UTC

!define IsEmptyDir `"" LL_IsEmptyDir`
!macro _LL_IsEmptyDir _a _b _t _f
!insertmacro _LOGICLIB_TEMP
System::Call `Shlwapi::PathIsDirectoryEmpty(t"${_b}")i.s`
Pop $_LOGICLIB_TEMP
!insertmacro _= $_LOGICLIB_TEMP 1 `${_t}` `${_f}`
!macroend

PoRtAbLe_StEaLtH
17th January 2013 05:28 UTC

Quote:

Anders
17th January 2013 10:18 UTC

Originally posted by gfm688
!define IsEmptyDir `"" LL_IsEmptyDir`
!macro _LL_IsEmptyDir _a _b _t _f
!insertmacro _LOGICLIB_TEMP
System::Call `Shlwapi::PathIsDirectoryEmpty(t"${_b}")i.s`
Pop $_LOGICLIB_TEMP
!insertmacro _= $_LOGICLIB_TEMP 1 `${_t}` `${_f}`
!macroend

You should change this code so it compares <> 0, BOOL can be > 1, it usually means success is non-zero...

PoRtAbLe_StEaLtH
17th January 2013 13:23 UTC

Thank you

Originally posted by Anders
You should change this code so it compares <> 0, BOOL can be > 1, it usually means success is non-zero...

How's this?


`

    !macro _LL_IsEmptyDir _a _b _t _f

   !insertmacro _LOGICLIB_TEMP

         System::Call `Shlwapi::PathIsDirectoryEmpty(t"${_b}")i.s`

    Pop $_LOGICLIB_TEMP

   !insertmacro _<> $_LOGICLIB_TEMP 0 `${_t}` `${_f}`

!macroend 

>

any recommendations for checking stack in a function/macro?

Originally Posted by gfm688 (Post 2908169) !define IsEmptyDir `"" LL_IsEmptyDir`
!macro _LL_IsEmptyDir _a _b _t _f
!insertmacro _LOGICLIB_TEMP
System::Call `Shlwapi::PathIsDirectoryEmpty(t"${_b}")i.s`
Pop $_LOGICLIB_TEMP
!insertmacro _= $_LOGICLIB_TEMP 1 `${_t}` `${_f}`
!macroend how come it works for me without popping?