I've been working on a script that accepts some command line parameters from the user. The first few lines in the program setup the constants I want to use in the rest of the program.
# Because of my C++ background
use constant PROJECT => $ARGV[0];
use constant ARCHIVE => $ARGV[1];
# debuggging
print "PROJECT value = " . PROJECT . "\n";
print "ARCHIVE value = " . ARCHIVE . "\n";
Later on in the program, I want to make a decision about the parameters, so I created the following if statment:
if( ARCHIVE eq "") {
warn( "No archive file was supplied.\n");
exit 1201;
}
Without specifying an ARCHIVE name, I would expect the script to die. It doesn't. So I started reading my trust Camel book on use constant. It said that constant is evaluated at compile time. That makes a lot of sense but my debug output shows:
PROJECT value = P:\Software
ARCHIVE value =
Why is perl able to set the PROJECT value, but can't work with the lack of an ARCHIVE value? Is this an error with my copy of Perl (ActiveState 5.6.1)?
-
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.
|