Some of these are "better" than others, but I've yet to see one that completly eliminates the risks, though they reduce the window for failure to the point of reasonable risk.
I would (perhaps naively) think that renaming the original file (renaming should be atomic, no?) to something like "$filename.$$", then reading / munging / writing to "$filename", and only deleting "$filename.$$" when the new filehandle is closed (and thus their buffers flushed as well as Perl can make them) would completely eliminate the risk. The process could stop at any point and, at worst, you'd have a partially munged new file and the original file both existant. Assuming, of course, that you have a sufficiently paranoid filesystem.
I'm not entirely sure I'm not missing something, so please enlighten me if I am. =)
bbfu
Black flowers blossom
Fearless on my breath
-
Are you posting in the right place? Check out Where do I post X? to know for sure.
-
Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
<code> <a> <b> <big>
<blockquote> <br /> <dd>
<dl> <dt> <em> <font>
<h1> <h2> <h3> <h4>
<h5> <h6> <hr /> <i>
<li> <nbsp> <ol> <p>
<small> <strike> <strong>
<sub> <sup> <table>
<td> <th> <tr> <tt>
<u> <ul>
-
Snippets of code should be wrapped in
<code> tags not
<pre> tags. In fact, <pre>
tags should generally be avoided. If they must
be used, extreme care should be
taken to ensure that their contents do not
have long lines (<70 chars), in order to prevent
horizontal scrolling (and possible janitor
intervention).
-
Want more info? How to link
or How to display code and escape characters
are good places to start.
|
