Try this It will save the "old" file to file with *.old as an extension and new file with original name with your modifications 
local $^I = '.old';
local @ARGV = ( 'your_file_name' );
my $find = "20150518";
my $replace = "18 May 2015";
while ( <>){
    s/$find/$replace/g;
        print;
}

[download]

In reply to Re: using s///g; by taiko
in thread using s///g; by ravi45722

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