If you have enough memory to read the entire file, this is probably faster: 
{
  local *ARGV;
  @ARGV = "yourfilenamehere";
  local $/;
  local $^I = ".bak"; # or "" if you don't want the backup
  $_ = <ARGV>;
  # truncate $_ as you wish: it's the entire file
  print;
}

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Note that neither your code nor mine works in a multi-thread/process environment. Not enough flocking. {grin}

-- Randal L. Schwartz, Perl hacker
Be sure to read my standard disclaimer if this is a reply.

In reply to •Re: Truncate the front of a file by merlyn
in thread Truncate the front of a file by flocto

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