I'm working with an application that has recently started generating very large log files (probably due to some yucky unchecked recursion? in one or more places in the code - it's not Perl :) ). The app is running in a windows environment, and the files get so big (>3GB) that the various windows ports of 'tail' that we use refuse to open them -- eg, 
tail: bigfile.log: Invalid argument
Assertion failed: valid_file_spec (f), file tail.c, line 700

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So I stepped in and slogged out some Perl to get the last 1000 lines of the file: 

open (FILE,"<bigfile.log");
while ($line = <FILE>) {
  $count++;
}
$numlines = $count;
$count = 0;
close FILE;

open (FILE,"<bigfile.log");
open (SMALLERFILE,">smallerfile.log");
while ($line = <FILE>) {
  $count++;
  if ($count > $numlines - 1000) {
    print SMALLERFILE $line;
  }
}
close FILE;
close SMALLERFILE;

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It works (it takes forever), but there's got to be a better way... :) I looked through the docs haven't had much luck. Any suggestions?

In reply to breaking up very large text files - windows by antichef

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