http://www.perlmonks.org?node_id=985743


in reply to Uer Perl Variable in txt file

Although choroba already warned against using eval - and he is certainly right with it -, you can consider an eval-solution, if you understand the risks (and, in particular, if you have control over what goes into your file).

In this case, you could do:

use strict; use warnings; while(my $line=<FH>) { print(eval "qq($line)"); }
This solution is much simpler than doing a substitution manually, but never forget: Whoever creates file.txt, can get *any* code being executed by your program; it requires that every variable referenced in the file, exists in the scope of evaluation (and will be replaced); and finally, that, if file.txt contains parentheses, that they are balanced.

-- 
Ronald Fischer <ynnor@mm.st>