From "perldoc -f grep":

Note that, because $_ is a reference into the list value, it can be used to modify the elements of the array.

Perhaps you meant  $_=~rather than $_= ? (Your script seems to work as you intended by adding the tilde :)

In reply to Re: Grep is changing the original list? by kschwab
in thread Grep is changing the original list? by iamcal

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