perl -p -i.bak -e 's/\$Log/\$History/gi' *

##</code><code>##

 $InputArray is a scalar not an Array.

##</code><code>##

#!/usr/bin/perl
use File::Find;
my @dirs = @ARGV;
@ARGV = ();
File::Find::find(
  {
    wanted => sub { push @ARGV, $File::Find::name if -f }
  },
  @dirs
);
local $^I;
while ( defined( $_ = <ARGV> ) ) {
  s/\$Log:/\$History:/gi;
  print;
}