Create the lock file if it doesn't exist. Then lock it, exclusively (such as via flock). No matter how your process dies, the lock will be released when the process is no longer running. Trying to lock the lock file will fail only if another process is already running. You don't even have to worry about a PID getting re-used. Don't have code that deletes the lock file. For monitoring convenience, after locking of the file succeeds, write your PID to the file.
This also has the major advantage of preventing a classic race condition where you end up with two instances running.
-
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.
|
