The following line copies files from one directory to the other only if it is newer. 
system("cp -u $copy_from $copy_to");

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I'm curious to know what the "right" way of doing this is, without relying on the 'system' command. File::Copy doesn't do it. Yeah, it'd be easy enough to roll my own but it just seems strange that I should have to. I'm curious to know where the lazy way might lie.

Also, just how "wrong" is it to use the 'system' command. Not portable and no easy way to verify success of the command. Anything else?

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In reply to Duplicating the 'cp' command's '-u' switch by nysus

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