Java routine constructs Perl logical expression from user input to be used in another system. Java application calls a small Perl script to validate the expression. These logical expressions contain =~ type comparisons. The validation of the proper use of a dollar sign ($) inside the regular expression is being complicated by Perl variable expansion. The Perl validation routine does detect an improper use of a $ in a regular expression when the variable substitution doesn't find a defined variable, but it misses those cases when it does, i.e., $$, $1, $2, etc. For example this is an improper regular expression /^Money$1/ the dollar should have been escaped, but Perl thinks it's fine after substituting the command line variable into it.

I need a way to disable the variable expansion, while preserving the interpretation of regular expression metacharacters.

In reply to Disabling Variable Expansion in regular expressions. by Anonymous Monk

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