Почему (свободное_пространство + использованное_пространство)! = Общий_размер в df? [дубликат]

Полагаю, ваш файл журнала выглядит так?

example.log:

[09:44:22] [main] ERROR [url/location] - A ONE LINE ERROR
[09:44:22] [main] ERROR [url/location] - A MULTI LINE ERROR 
    with whitepace indention
[09:44:22] [main] ERROR [url/location] - A MULTI LINE ERROR 
       with tab indention
[09:44:22] [main] SOMETHING DIFFERENT
[09:44:22] [main] SOMETHING DIFFERENT
       with tab indention
[09:44:22] [main] WARN [url/location] - ANOTHER ONE LINE WARN

По общему признанию, он не однострочный и написан на Perl, но он должен выполнять свою работу:

logsifter.pl:

#!/usr/bin/perl
use warnings;
use strict;

my $buffer="";

while(my $line= <>){
  chomp $line;
  if($line=~/ERROR|INFO|WARN/){
    print "$buffer\n" if $buffer;
    $buffer = $line;
  }
  elsif($line=~/^\s+(.*)$/){
    $buffer .= $1 if $buffer;
  }
  else{
    if($buffer){
      print "$buffer\n";
      $buffer ="";
    }
  }
}

print "$buffer\n";

call это вроде:

perl logsifter.pl < example.log
 [09:44:22] [main] ERROR [url/location] - A ONE LINE ERROR
 [09:44:22] [main] ERROR [url/location] - A MULTI LINE ERROR with whitepace indention
 [09:44:22] [main] ERROR [url/location] - A MULTI LINE ERROR with tab indention
 [09:44:22] [main] WARN [url/location] - ANOTHER ONE LINE WARN