Determining if a file is open

[jswingchun]

Is there a way for a script to determine if a file is open (not busy) without using lsof in a shell script? I have searched the forum and found some handy lsof shells that pointed me in that direction. It works, but watching Activity Monitor, the lsof process spikes up to 97% of the CPU every time it runs! That is even when I am searching only a single directory. I know that the “info for file” command reports back busy status, but open files are not busy files.

Here is the lsof script I am running now, maybe something could be done to make it less processor intensive.

set source_folder to (alias "TheVolume:ThePath:TheFile:")
set var to false
repeat until var = true
	try
		set the_files to (do shell script "lsof -F n +D " & (quoted form of POSIX path of source_folder))
	on error the_error
		if the_error = "The command exited with a non-zero status." then
			set var to true
			display dialog "The Document is closed"
		else
			set the_files to the_error
		end if
	end try
	delay 1
end repeat

Thanks!
jim

[mark_hunte]

looking at man page for Isof

+D
is for drilling down a whole directory and looking at every file etc.

Further note: lsof may process this option slowly and require
a large amount of dynamic memory to do it. This is because it
must descend the entire directory tree, rooted at D, calling
stat(2) for each file and directory, building a list of all
the files it finds, and searching that list for a match with
every open file. When directory D is large, these steps can
take a long time, so use this option prudently.

are you sure you should not be using

+d

Not +D

+d stops Isof following symbolic links, which maybe what you wanted.

+d s This option causes lsof to search for all open instances of
directory s and the files and directories it contains at its
top level. This option does NOT descend the directory tree,
rooted at s. The +D D option may be used to request a
full-descent directory tree search, rooted at directory D.

            Processing  of  the  +d  option does not follow symbolic links
            within s unless the -x or -x  l option is also specified.  Nor
            does  it  search for open files on file system mount points on
            subdirectories of s unless the -x or  -x   f  option  is  also
            specified.

[jswingchun]

Thanks for the reply. You are correct, I didn’t need the +D. That’s what I get since I don’t know what I’m are doing and I copy stuff off other posts. The folder I was checking with lsof is only one level deep anyway. It still used 97% of the CPU even when I took out the +R, so back to the drawing board.