if条件下的命令[重复]

【问题标题】：Commands within if condition [duplicate]if条件下的命令[重复]
【发布时间】：2016-07-29 19:06:06
【问题描述】：

我是脚本新手

谁能帮我解决我下面的脚本出了什么问题。我收到一个错误。

if `tail -2 jeevagan/sample/logs.txt | head -1 | grep "Start Outputing Report"` = TRUE && `tail -1 jeevagan/sample/logs.txt | grep "Start Outputing Report"` = TRUE

then
        echo "report error"
else
        echo "report good"
fi

在日志文件中，我有如下日志：

2016-04-07 06:57:36,248 INFO : Finished Outputing Report:, Format:EXCEL, Locale: en_IN
2016-04-07 07:06:52,812 INFO : Start Outputing Report:, Format:EXCEL, Locale: en_IN
2016-04-07 06:52:56,451 INFO : Finished Outputing Report:, Format:EXCEL, Locale: en_IN
2016-04-07 06:52:56,451 INFO : Finished Outputing Report:, Format:EXCEL, Locale: en_IN
2016-04-07 07:06:52,812 INFO : Start Outputing Report:, Format:EXCEL, Locale: en_IN
2016-04-07 07:06:52,812 INFO : Start Outputing Report:, Format:EXCEL, Locale: en_IN
2016-04-07 07:06:52,812 INFO : Start Outputing Report:, Format:EXCEL, Locale: en_IN

【问题讨论】：

标签： linux shell scripting command

【解决方案1】：

来自我的 solaris 系统上的“man bash”：

command1 && command2
command2 is executed if, and only if,  command1  returns  an
exit status of zero.

要检查退出状态，请运行命令，然后

echo $?

所以

tail -2 log.txt | head -1 | grep "Start Outputing Report"

返回 0

所以你可以像这样把它们串在一起

tail -2 log.txt | head -1 | grep "Start Output" && tail -1 log.txt | grep "Start Output" && echo "report error"

或编写类似的脚本

tail -2 log.txt | head -1 | grep "Start Output" && tail -1 log.txt | grep "Start Output" 

return=$?

if [[ $return == 0 ]]; then
    echo "report error"
else
    echo "report good"
fi

【讨论】：