Suggestion: IfFileInUse

gLes
3rd June 2003 14:47 UTC

Suggestion: IfFileInUse
Hi there!

Above you see the thing I'm really missing from NSIS. I know I could do it with a little *hard* coding (at least for me), but it would be much better if I could use this function like this:

IfFileInUse file_to_check_for jump_if_inuse [jump_otherwise]

Just like the IfFileExists function. Actually the two function should be combined. I imagine the code (the *real* code like this):

function IfFileInUse(F: PChar): Boolean;
begin
  Result := False; //Initial result
  if FileExists(F) then //Check if file exists, and if so, then check whether it's in use
    Result := CreateFile(F, GENERIC_WRITE, 0, nil, OPEN_EXISTING, 0, 0) = INVALID_HANDLE_VALUE;
end;

Sorry, but since I only know Delphi Pascal my imagination can't do better either ;)

Best regards,
gLes

kichik
3rd June 2003 18:39 UTC

It's not hard coding at all:

ClearErrors
FileOpen $0 "path" "a"
FileClose $0
IfErrors locked notlocked

gLes
3rd June 2003 19:57 UTC

Doh! But wouldn't it be easier to do it my way?:)

Joost Verburg
3rd June 2003 20:47 UTC

That will increase the overhead. This is easy enough (if you want to make it even easier, create a macro).

gLes
3rd June 2003 21:21 UTC

How that look like?:)

Joost Verburg
3rd June 2003 21:56 UTC

!macro IfFileInUse FILE GOTONOTLOCKED GOTOLOCKED

ClearErrors

Push $R0

  FileOpen $R0 "${FILE}" "a"
  FileClose $R0

Pop $R0

IfErrors "${GOTONOTLOCKED}" "${GOTOLOCKED}"

!macroend

Usage:

!insertmacro IfFileInUse "c:\bla.txt" notlocked locked

Joel
3rd June 2003 22:08 UTC

Maybe I'll be cool if there is an instruction like the one:


IfFileExists

Simple, easy and handy :)

gLes
3rd June 2003 22:08 UTC

Thx. :)

Joost Verburg
3rd June 2003 22:18 UTC

Lobo Lunar, that will increase the installer overhead. I think a macro is simple enough.

bradkohl
11th December 2007 07:27 UTC

I don't think that's a reasonable solution to the problem at all. What happens if the file is a 30 MB data file?

kichik
11th December 2007 09:28 UTC

How does the size affect anything?

And with LogicLib this is even easier.

!macro _FileInUse _a _b _t _f
  !insertmacro _LOGICLIB_TEMP
  ClearErrors
  FileOpen $_LOGICLIB_TEMP `${_b}` "a"
  FileClose $_LOGICLIB_TEMP
  IfErrors `${_t}` `${_f}`
!macroend

!define FileInUse `"" FileInUse`

${If} ${FileInUse} $INSTDIR\file
  DetailPrint "in use"
${EndIf}

bradkohl
11th December 2007 10:45 UTC

It all depends on the system and file but in my experience the larger the file the longer fileopen takes, I just think there could be a better way.

bradkohl
11th December 2007 11:02 UTC

oh I didn't see the "a" my bad