regex – perl Regular Expression按关键字查找Java StackTrace

我需要通过关键字从logfile grep完整的堆栈跟踪.

这段代码工作正常,但是对于大文件来说速度慢(比文件慢一点).
我认为提高正则表达式找到关键字的最佳方法,但我无法完成它.

#!/usr/bin/perl

use strict;
use warnings;

my $regexp;
my $stacktrace;
undef $/;

$regexp = shift;
$regexp = quoteMeta($regexp);

while (<>) {
  while ( $_ =~ /(?<LEVEL>^[E|W|D|I])\s
                 (?<TIMESTAMP>\d{6}\s\d{6}\.\d{3})\s
                 (?<THREAD>.*?)\/
                 (?<CLASS>.*?)\s-\s
                 (?<MESSAGE>.*?[\r|\n](?=^[[E|W|D|I]\s\d{6}\s\d{6}\.\d{3}]?))/gsmx ) {
    $stacktrace = $&;
    if ( $+{MESSAGE} =~ /$regexp/ ) {
      print "$stacktrace";
    }
  }
}

用法：./ grep_log4j.pl< pattern> <文件>

示例：./ grep_log4j.pl Exception sample.log

我认为$stacktrace = $&amp ;;因为如果删除此字符串并只是打印所有匹配的行脚本工作得很快.
用于打印所有匹配项的脚本版本：

#!/usr/bin/perl

use strict;
use warnings;

undef $/;

while (<>) {
  while ( $_ =~ /(?<LEVEL>^[E|W|D|I])\s
                 (?<TIMESTAMP>\d{6}\s\d{6}\.\d{3})\s
                 (?<THREAD>.*?)\/
                 (?<CLASS>.*?)\s-\s
                 (?<MESSAGE>.*?[\r|\n](?=^[[E|W|D|I]\s\d{6}\s\d{6}\.\d{3}]?))/gsmx ) {
    print_result();
  }
}

sub print_result {
    print "LEVEL: $+{LEVEL}\n";
    print "TIMESTAMP: $+{TIMESTAMP}\n";
    print "THREAD: $+{THREAD}\n";
    print "CLASS: $+{CLASS}\n";
    print "MESSAGE: $+{MESSAGE}\n";
}

用法：./ grep_log4j.pl< file>

示例：./ grep_log4j.pl sample.log

Lo4j模式：％-1p％d％t /％c {1} – ％m％n

日志文件示例：

I 111012 141506.000 thread/class - Received message: something
E 111012 141606.000 thread/class - Failed handling mobile request
java.lang.NullPointerException
  at javax.servlet.http.HttpServlet.service(HttpServlet.java:710)
  at java.lang.Thread.run(Thread.java:619)
W 111012 141706.000 thread/class - Received message: something
E 111012 141806.000 thread/class - Failed with Exception
java.lang.NullPointerException
  at javax.servlet.http.HttpServlet.service(HttpServlet.java:710)
  at java.lang.Thread.run(Thread.java:619)
D 111012 141906.000 thread/class - Received message: something
S 111012 142006.000 thread/class - Received message: something
I 111012 142106.000 thread/class - Received message: something
I 111013 142206.000 thread/class - Metrics:0/1

我的正则表达式你可以在http://gskinner.com/RegExr/上找到log4j关键字：

解决方法

您正在使用：

$/ = undef;

这使得perl将整个文件读入内存.

我会像这样逐行处理这个文件(假设堆栈跟踪与跟踪上方的消息相关联)：

my $matched;
while (<>) {
  if (m/^(?<LEVEL>\S+) \s+ (?<TIMESTAMP>(\d+) \s+ ([\d.])+) \s+ (?<THREADCLASS>\S+) \s+ - \s+ (?<REST>.*)/x) {
    my %captures = %+;
    $matched = ($+{REST} =~ $regexp);
    if ($matched) {
      print "LEVEL: $captures{LEVEL}\n";
      ...
    }
  } elsif ($matched) {
    print;
  }
}

这是解析多行块的一般技术.
以下循环一次读取一行STDIN,并将日志文件的完整块提供给子例程进程：

my $first;
my $stack = "";
while (<STDIN>) {
  if (m/^\S /) {
    process($first,$stack) if $first;
    $first = $_;
    $stack = "";
  } else {
    $stack .= $_;
  }
}
process($first,$stack) if $first;

sub process {
  my ($first,$stack) = @_;
  # ... do whatever you want here ...
}

regex – perl Regular Expression按关键字查找Java StackTrace

解决方法

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