Here's yet another way, demonstrated from the shell:
Make the pipe, and...
$ mkfifo logpipe
$ perl -e 'open PIPE, "< logpipe"; { select 1<<fileno(PIPE),undef,unde
+f,undef; print <PIPE>;redo}' &
... start a simple server in the background.
select makes it sleep till
PIPE is readable.
redo in a bare block loops forever. Kick the tires:
$ echo foo >logpipe
foo
$ echo far >logpipe
$ far
echo fie >logpipe
fie
$
The asynchronous operation of the server is shown in the staggered output. Clean up with
$ fg
perl -e 'open PIPE, "< logpipe"; {select 1<<fileno PIPE,undef,undef,un
+def;print <PIPE>;redo}'
# do a Ctrl-C here
$
I think this is the Right Way® to handle your log file problem. Sleeping till there is something to read will save a lot of load on the host.
Update: Changed to use mkfifo instead of mknod, and repaired a pasto in the timeout arg of select.
After Compline,
Zaxo
-
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.