Many functions in Perl can be called with a variable number of arguments. For example, split:

split /PATTERN/,EXPR,LIMIT
split /PATTERN/,EXPR
split /PATTERN/

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In this case, Perl will assume some default values for the arguments you don't specify. In the case of open, you can do:

open FILEHANDLE,EXPR
open FILEHANDLE,MODE,EXPR
open FILEHANDLE,MODE,EXPR,LIST
open FILEHANDLE,MODE,REFERENCE
open FILEHANDLE

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As you can see, there's more than one way to do it :^). You're being advised to use the three argument form of open, which normally reads like this:

open $fd, '<', 'input_file'    or die "open: $!";    ## <-- you should always check for errors.
my $input = do {local %/; <AA>;};

As for this, first take a look to Coping with scoping to understand what local means.

--
David Serrano

In reply to Re^5: What is the right way of concatenating strings by Hue-Bond
in thread What is the right way of concatenating strings by cool

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