just a sidenote: (of course using eval in your context is extremely not secure, so you might want to change your code logic to include specific expressions: like if you want them to evaluate '5 < 7' then take the inputs each one alone and test them one by one to construct the expression, or something like that)
anyway 
if (eval($expression)) {
  $output = $true;
} else {
  $output = $false;
}

[download]
using eval() will not tell you what went wrong, you probably want to use the eval-BLOCK to catch errors and warnings in $@. 
eval { $expression };
$output = defined $@ ? $false : $true;

[download]
He who asks will be a fool for five minutes, but he who doesn't ask will remain a fool for life.

Chady | http://chady.net/

In reply to Re: securely evaluating an expression by Chady
in thread securely evaluating an expression by Len

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