Two ways.
1. You can tell Perl to use the C preprocessor with the command line option -P. Be sure to read the limitations of the switch, as documented in perlrun.
2. Use constant folding to remove the checks at runtime. In the following, notice how the debug code is removed when (and only when) a constant expression is used in the if:
>perl -MO=Deparse -e "$DEBUG = 0; print(qq{debug\n}) if $DEBUG; print(
+qq{end\n})"
$DEBUG = 0;
print "debug\n" if $DEBUG;
print "end\n";
-e syntax OK
>perl -MO=Deparse -e "use constant DEBUG => 0; print(qq{debug\n}) if D
+EBUG; print(qq{end\n})"
use constant ('DEBUG', 0);
'???';
print "end\n";
-e syntax OK
-
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.
|
