File in use while open for writing

[LiquidFire]

Hi,

Recently I upgraded to the latest version of AutoIt (the one I was using was at least half a year old, not sure which one it was exactly). My code runs fine with the new version, but I noticed a change in behaviour when opening files for writing.

Some of my scripts open a log file and periodically write to it. With the latest version of AutoIt, while the file is open for writing I can't open it (even read-only) with another program.

A simple demonstration of the problem:

Local $file = FileOpen("test.txt", 1)
FileWriteLine($file, "1")
Sleep(10000) ; while it's waiting, try to open the file with e.g. notepad - it will say it's being used by another process
FileWriteLine($file, "2")
FileClose($file)

This makes it impossible to look at my log files until the script has finished running. Is there any way to open the file for writing without locking it?

The only reason I updated to the latest version was so I could use FileFlush, but that's useless if I can't look at the file at all!

Any help is appreciated.

[jchd]

There was a recent discussion about this issue. I personnally believe this is a regression due to changed flags within FileOpen. Developpers could consider looking closer to the issue if people affected would comment again on the existing (similar but not identically phrased) ticket. See this thread.

[LiquidFire]

Thanks for the response. I'll go comment on the bugs.

Do you know of any workarounds currently?

I guess I could just downgrade to 3.3.2.0 since it has FileFlush, but supposedly doesn't yet have this "bug fix".

[jchd]

That's the whole extent of my knowledge. Perhaps v3.3.2.0 will be fine for you in the interim.

[Bowmore]

You could use a text file editor/viewer that is capable of opening files in read mode that other applications have locked for writing. TextPad and UltraEdit are 2 of many that come to mind. Notepad needs to be able to lock a file before it will open it.

[LiquidFire]

Nothing seems to be able to open the file while it's opened for writing (and I need to be able to read it from a Python script, not a text editor anyway).

However, I posted a comment in the bug tracker and apparently it works again in the latest betas (since 3.3.5.3).

[picaxe]

Look at

_WinAPI_CreateFile($sFile, 2, 2, 6) ; open for read, $iAccess=r, $iShare=r+w

and

_WinAPI_SetFilePointer
_WinAPI_ReadFile

[LiquidFire]

Thanks for the suggestions, picaxe. The resulting file handle wouldn't work with AutoIt's File* functions though, would it? I think I'll just use the beta or older version where this isn't a problem, rather than rewrite my code to use WinAPI directly.

Edited February 21, 2010 by LiquidFire