Detailed explanation of how to use grep to obtain MySQL error log information

#!/usr/bin/env python2.7
#-*- encoding: utf-8 -*-
 
"""
This module is used to extract abnormal or error information from the daily MySQL log author: xiaomo
email: [email protected]
"""
 
import os
import sys
import string
from datetime import *
 
# Default character decoder is utf-8
reload(sys)
sys.setdefaultencoding('utf-8') 
 
COMMON_FLAGS = ["error", "exception", "fail", "crash", "repair"]
 
def _contain_flag(cur_str):
  for flag in COMMON_FLAGS:
    if flag in string.lower(cur_str):
      return True
  return False
 
"""
Get the error_log file path of the current MySQL instance"""
def _get_mysql_error_log_path():
  log_path = ''
  grep_infos = os.popen('ps aux | grep mysql | grep "log-error"').read()
  if len(grep_infos) > 1:
    grep_infos = grep_infos.split("log-error=")
  if len(grep_infos) > 1:
    grep_infos = grep_infos[1].split(' ')
  if len(grep_infos) > 1:
    log_path = grep_infos[0]
  return log_path
 
"""
Read the line containing exception or error information in the MySQL error log"""
def _get_error_info(error_log, begin_date):
  error_infos = []
  f = open(error_log, 'r')
  lines = f.readlines()
  for line in lines:
    data_array = line.split(' ')
    if len(data_array) > 0 and len(data_array[0]) == 10:
      dt_strs = data_array[0].split('-')
      cur_date = date(int(dt_strs[0]), int(dt_strs[1]), int(dt_strs[2]))
      if cur_date >= begin_date and _contain_flag(line):
        error_infos.append(line)
  f.close()
  return error_infos
 
"""
Assemble and return mysql error log information"""
def get_mysql_errors(begin_date=date.today()-timedelta(1)):
  try:
    err_log_path = _get_mysql_error_log_path()
    if len(err_log_path) > 1:
      return _get_error_info(err_log_path, begin_date)
  except Exception,e:
    print "[get_mysql_errors]%s"%e  
  return []