On a system that has GNU mv (and perhaps other implementation of mv have the -u option as well), I'd do: 
    system mv => '-u', "B/ABC.txt", "A/ABC.txt" and die;

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Perl, after all, is a glue language, and there's nothing wrong with reusing code.

Luckely, GNU fileutilities (which includes mv) have been ported to almost any platform Perl runs on (and then some).

In reply to Re: Function to replace a old file with newer version by JavaFan
in thread Function to replace a old file with newer version by hiradhu

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