my @output = map s/(.*)/    $1\n/, @small_files;

The substitution operator s returns the number of captured substrings, which is 1. It also alters the string it is bound to ($_ by default, as you are aware), but this alteration is by side-effect. Check the contents of @small_files immediately after this statement.

What you want is

my @output = map "    $_\n", @small_files;

Updated: I am taking the liberty of deleting the false part of my original answer (which is accurately quoted and accurately corrected in kyle's reply below). Thanks, kyle. What was I thinking?

In reply to Re: Newbie: parentheses, map, etc. by Narveson
in thread Newbie: parentheses, map, etc. by nefigah

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