Hi, Can someone help me figure out how to do nested variable resolves and evaluation of numeric operations? I am trying to make a system that stores formulas and variable values in an external file, and i want my perl script to pull in the values and the formulas, and then evaluate the formula with the variables having their values substituted into the formula. A small, representative, and problematic piece of code follows:

my $x = 3;
my $y = "2 * $x";
my $z = eval {$y};

print '$z is: ', $z, "\n";
print 'eval of $z is: ', eval{$z}, "\n";
print 'eval of "2 * 3" is: ', eval '2 * 3', "\n";
[download]

What I want is for the 2nd print statement to evaluate to the value '6', which the 3rd print statement does. Below is what I get:

$z is: 2 * 3
eval of $z is: 2 * 3
eval of "2 * 3" is: 6

Again, can someone help me figure out how to do nested variable resolves and evaluation of numeric operations? Thanks, Matt

---

---

• 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.