Re: Re: Re: Update in-place with temporary file and flocking

I can not see a second read-write sequence. The operations are the same for both examples.

Boris

Comment on Re: Re: Re: Update in-place with temporary file and flocking

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Re: Re: Re: Re: Update in-place with temporary file and flocking by geohar (Acolyte) on Feb 18, 2004 at 20:00 UTC
I may have misread/understood your code, but in order to be able to open and lock file1 wouldn't it have to be: `copy "file1", "file2"; # instead of move my $fh = new IO::File("file1","w") flock($fh,LOCK_EX) or die "can't get lock"; my $fh2 = new IO::File("file2","r"); #read fh2 write to $fh flock($fh,LOCK_UN); # perhaps delete file2` [download] With the rename, even if we could create a file1 to subsequently lock, wouldn't there'd be a small gap where a program could attempt to get read access to file1 and find it not there...	[reply] [d/l]

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Re: Re: Re: Re: Update in-place with temporary file and flocking
by geohar (Acolyte) on Feb 18, 2004 at 20:00 UTC

copy "file1", "file2"; # instead of move
my $fh = new IO::File("file1","w")
flock($fh,LOCK_EX) or die "can't get lock";
my $fh2 = new IO::File("file2","r");
#read fh2 write to $fh
flock($fh,LOCK_UN);
# perhaps delete file2
[download]

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[d/l]