Oracle - 截取指定日期的alert log

工作中DBA经常会查看alert log来检查数据库后台都记录了些什么日志，如果只想看某一天或者某段时间范围的日志，能够把这些日志从大的alert log中截取下来放到一个单独的文件中，对于查看和下载都是很有意义的事，接下来附上脚本

script.sh

#!/bin/bash
################################################################################
# this script is to get the specified date log of oracle database alert log.   #
# author: yangbao                                                              #
# usage: ./script.sh 2019-5-1 --> get the log on 2019-5-1                      #
# ./script.sh 2019-5-1 2019-5-3 --> get the log between 2019-5-1 and 2019-5-3  #
################################################################################

# 判断日期格式是否有效
check_date() {
    date -d "$1" &> /dev/null
    flag=$?
    if [ $flag -eq 1 ]; then
       echo "date is incorrect, please input the correct date formate like 2019-5-1."
       exit 1
    fi    
}

# 得到开始和结束的日期的指定格式
get_begin_time() {
    year1=`date -d "$1" +%Y`
    month1=`date -d "$1" +%b`
    day1=`date -d "$1" +%d`
    week1=`date -d "$1" +%a`
}

get_end_time() {
    year2=`date -d "$1" +%Y`
    month2=`date -d "$1" +%b`
    day2=`date -d "$1" +%d`
    week2=`date -d "$1" +%a`
}

# 判断输入的参数个数是否正确
cnt=$#
if [ $cnt -eq 0 ]; then
    echo "you must input at least one date, formate like 2019-5-1."
    exit 1
elif [ $cnt -eq 1 ]; then
    var1=$1
    check_date $var1
    get_begin_time $var1
    get_end_time $var1   
elif [ $cnt -eq 2 ]; then
    var1=$1
    var2=$2
    check_date $var1
    check_date $var2
    t1=`date -d "$var1" +%s`
    t2=`date -d "$var2" +%s`
    if [ $t1 -gt $t2 ]; then
        temp=$var1
        var1=$var2
        var2=$temp
    fi
    get_begin_time $var1
    get_end_time $var2   
elif [ $cnt -gt 2 ]; then
    echo "you input too much arguments, at most two arguments allowed." 
    exit 1
fi

# 查找alert日志所在的路径
sqlplus -s /nolog &> /dev/null << eof
set feedback off heading off verify off trimspool on timing off
set pagesize 0 linesize 300
conn / as sysdba;
spool /tmp/tmpdir.txt
select value from v\$parameter where name='background_dump_dest'; 
spool off
exit;
eof

errs=`grep 'ERROR' /tmp/tmpdir.txt | wc -l`
if [ $errs -gt 0 ]; then
    echo "query alert log direction run error, please check the /tmp/tmpdir.txt for details."
    exit 1
else
    dir=`cat /tmp/tmpdir.txt`
fi

# 得到日志开始和结束的行数
row1=`find $dir/alert_$ORACLE_SID.log | xargs grep -n "$week1 $month1 $day1" | grep "$year1" | head -n 1 | cut -d ":" -f 1`
if [ "$row1" == "" ]; then
    echo "$1 is not found in alert log"
    exit 1
fi

row2=`find $dir/alert_$ORACLE_SID.log | xargs grep -n "$week2 $month2 $day2" | grep "$year2" | tail -n 1 | cut -d ":" -f 1`
if [ "$row2" == "" ]; then
    echo "$2 is not found in alert log"
    exit 1
fi
row2=$(($row2+10))

# 截取日志
if [ $cnt == 1 ]; then
    sed -n "${row1},${row2}p" $dir/alert_$ORACLE_SID.log > ./alert_$ORACLE_SID.$var1.log
    echo "alert_$ORACLE_SID.$var1.log has created!"
elif [ $cnt == 2 ]; then
    sed -n "${row1},${row2}p" $dir/alert_$ORACLE_SID.log > ./alert_$ORACLE_SID."$var1"_to_"$var2".log
    echo "alert_$ORACLE_SID."$var1"_to_"$var2".log has created!"    
fi
exit 0

使用说明：

1.使用oracle用户执行，脚本会自动寻找alert日志的位置

2.如果只查一天的日志，如2019-5-1这天的日志，则使用./script.sh 2019-5-1

3.如果查一段时间范围的日志，如2019-5-1到2019-5-10这10天的日志，则使用./script.sh 2019-5-1 2019-5-10

4.执行完成之后会在当前目录生成一个新文件

5.输入的日期必须在alert日志中存在才会有新文件生成，否则会报错