计算bash脚本中的时差

Question

我需要计算RMAN start和RMAN End之间的时差。日志就像这样

-rw-r----- oracle/dba 2017-03-11 21:56:35 storage/backup/daily/ALG_PDB_2drut5jf.alg
-rw-r----- oracle/dba 2017-03-11 21:56:34 storage/backup/daily/ALG_PDB_2erut5jf.alg
-rw-r----- oracle/dba 2017-03-11 21:56:07 storage/backup/daily/ALG_PDB_2frut5jf.alg
-rw-r----- oracle/dba 2017-03-11 21:56:29 storage/backup/daily/ALG_PDB_2grut5jv.alg
-rw-r----- oracle/dba 2017-03-11 21:39:14 storage/backup/daily/BKPPDB_28rut42s.F_bkp
-rw-r----- oracle/dba 2017-03-11 21:47:28 storage/backup/daily/BKPPDB_29rut42s.F_bkp
-rw-r----- oracle/dba 2017-03-11 21:42:41 storage/backup/daily/BKPPDB_2arut42s.F_bkp
-rw-r----- oracle/dba 2017-03-11 21:55:33 storage/backup/daily/BKPPDB_2brut4k8.F_bkp
-rw-r----- oracle/dba 2017-03-11 21:55:36 storage/backup/daily/c-2819904582-20170311-00
-rw-r----- oracle/dba 2017-03-11 21:56:42 storage/backup/daily/c-2819904582-20170311-01
-rw-r----- oracle/dba 2017-03-11 21:56:41 storage/backup/daily/control_PDB_2hrut5kp.ctl

我编写了一个脚本，首先根据第4列对列进行排序，即时间，下面是脚本

#!/bin/bash -x
if [ -f /storage/backup/weekly/DB-Backup-$(date -d "yesterday" '+%a-%d%m%y').tgz ]
 then

export StartMin=$(tail -30 /storage/backup/weekly/DailyCompressionLog|grep "^-\|^ -" |sort -k5|awk '{print $5}' |awk -F ":" '{print $2}'|awk 'NR==1; END{print}'|awk 'FNR==1 {print $1}')
export EndMin=$(tail -30 /storage/backup/weekly/DailyCompressionLog|grep "^-\|^ -" |sort -k5|awk '{print $5}' |awk -F ":" '{print $2}'|awk 'NR==1; END{print}'|awk 'FNR==2 {print $1}')

export StartHour=$(tail -30 /storage/backup/weekly/DailyCompressionLog|grep "^-\|^ -" |sort -k5|awk '{print $5}' |awk -F ":" '{print $1}'|awk 'NR==1; END{print}'|awk 'FNR==1 {print $1}')
export EndHour=$(tail -30 /storage/backup/weekly/DailyCompressionLog|grep "^-\|^ -" |sort -k5|awk '{print $5}' |awk -F ":" '{print $1}'|awk 'NR==1; END{print}'|awk 'FNR==2 {print $1}')

echo "Backup for `date -d "yesterday" '+%a-%d%m%y'`" >> /storage/backup/weekly/MonthlyCompressionLog
echo -e "RMAN Backup Started at $StartHour":"$StartMin" >> /storage/backup/weekly/MonthlyCompressionLog
echo -e "RMAN Backup Ended   at $EndHour":"$EndMin" >> /storage/backup/weekly/MonthlyCompressionLog
echo -e "Time taken to Complete Backup Job Hours:Mins $((EndHour-StartHour))":"$((EndMin-StartMin))" >> /storage/backup/weekly/MonthlyCompressionLog

echo -e "-------------------------------------------------------\n" >> /storage/backup/weekly/MonthlyCompressionLog

当脚本工作时（成功）

如果结束时间大于StartTime

脚本失败时

在当前状态下，如果开始时间大于结束时间，在这种情况下，Endhour将大于StartHour

场景::让我们说如果RMAN在14:56开始并在15:02完成，在这种情况下，从开始到结束的总时间仅为00:06 Min但脚本将显示1：-54

任何想法......

Answer 1

不是单独计算小时数和分钟数，而是计算自开始和结束午夜以来的分钟数，并使用它来执行算术。

类似于：

StartNumMins=$(( $StartHour * 60 + $StartMin ))
EndNumMinutes=$(( $EndHour * 60 + $EndMin ))

MinutesDiff=$(( $EndNumMinutes - $StartNumMins ))

DiffHours="0$(($MinutesDiff / 60))"
DiffMins="0$(($MinutesDiff % 60))"

echo "Diff is $MinutesDiff minutes, which is ${DiffHours:-2}:${DiffMins:-2}"

产生：

Diff is 6 minutes, which is 00:06

当然，如果您的过程跨越午夜，那么您必须考虑开始/结束日期，而不仅仅是时间。有几个选项可以做到这一点（例如使用GNU＆＃39;日期＆＃39;如果您可以使用它 - 例如。请参阅Convert an ISO date to seconds since epoch in linux bash），但是那个＆＃39;另一个问题。