#!/usr/bin/perl

undef $/;

&doStuff();
&foo();

sub doStuff {
   # want to read the file as a single string....
   open TMP, "<somefile.txt";
   my @file = <TMP>;
   close TMP;
   # do more stuff with that file...
}
sub foo {
   ## here i would want to read the file line-by-line
   
   $/ = '\n';
   open TMP, "<otherfile.txt";
   my @file = <TMP>;
   close TMP;


}