无限循环？检查两台打印机是不是在线或离线 - 如果关闭则发送电子邮件

Posted 2023-03-15

【中文标题】无限循环？检查两台打印机是不是在线或离线 - 如果关闭则发送电子邮件

【英文标题】：Indefinitely Looping ? Check Two Printers if Online or Offline - Send Email if Down无限循环？检查两台打印机是否在线或离线 - 如果关闭则发送电子邮件

【发布时间】：2021-08-02 01:03:53

【问题描述】：

我有这个无限循环的脚本——有两台打印机要检查一次——printer01 和printer02。如果它们关闭或关闭，则发送电子邮件。 为什么它在第一台printer01上无限循环？

#!/bin/ksh
c=1
while [[ $c -le 3 ]]; do
STATUS=$(lpstat -printer0$c| grep 'READY' | awk 'print $3')

if [[  ! $STATUS == "DOWN" ||! $STATUS == "OFF" ]] ; then

        #create email summary and send

        today=`date +%m%d%Y`

        echo "*** START EMAIL SUMMARY ***                                    " > /lsf10/monitors/lpstat_email_$today.txt
        echo "*                                                              " >> /lsf10/monitors/lpstat_email_$today.txt
        echo "* Date - `date`                                                " >> /lsf10/monitors/lpstat_email_$today.txt
        echo "*                                                              " >> /lsf10/monitors/lpstat_email_$today.txt
        echo "* Start time   => $s_time                                      " >> /lsf10/monitors/lpstat_email_$today.txt
        echo "* Current time => `date +%H:%M:%S`                             " >> /lsf10/monitors/lpstat_email_$today.txt
        echo "*                                                              " >> /lsf10/monitors/lpstat_email_$today.txt
        echo "* Printer email message will be here for you to modify         " >> /lsf10/monitors/lpstat_email_$today.txt
        echo "* Please investigate.                                          " >> /lsf10/monitors/lpstat_email_$today.txt
        echo "*                                                              " >> /lsf10/monitors/lpstat_email_$today.txt
        echo "*** END EMAIL SUMMARY ***                                      " >> /lsf10/monitors/lpstat_email_$today.txt

        `mail -s "Mobius Printer Down Alert!" "email1,email2" < /lsf10/monitors/lpstat_email_$today.txt`
fi
c = $c + 1
done
exit

【问题讨论】：

不要在mail 命令周围加上反引号：这将执行命令，替换输出，然后尝试将输出作为命令执行。。跨度>

【参考方案1】：

考虑在每个外部命令之后添加错误检查。

您可以使用ksh -x 运行您的脚本来查看您的错误，这将打开调试模式。您也可以通过在脚本中添加set -x 来做到这一点。

您的脚本正在循环，因为变量 $c 没有按照您的想法设置。

您可能需要检查每个外部命令的退出代码 ($?)，还要检查 lpstat 返回的标准输出是否为空或任何错误，并验证邮件程序是否在 PATH 上并且可执行等等

尝试不同的方法，如下所示：

#!/bin/ksh
typeset +i c=1 
while (( c <= 2 )); do
    STATUS=$(lpstat -printer0$c| grep 'READY' | awk 'print $3')
    if [[  ! $STATUS == "DOWN" ||! $STATUS == "OFF" ]] ; then
        #create email summary and send

        today=`date +%m%d%Y`
        outfile=/tmp/lpstat_email_$today.txt  # use your own path

        echo "*** START EMAIL SUMMARY ***                                    " > $outfile
        echo "*                                                              " >> $outfile
        echo "* Date - `date`                                                " >> $outfile
        echo "*                                                              " >> $outfile
        echo "* Start time   => $s_time                                      " >> $outfile
        echo "* Current time => `date +%H:%M:%S`                             " >> $outfile
        echo "*                                                              " >> $outfile
        echo "* Printer email message will be here for you to modify         " >> $outfile
        echo "* Please investigate.                                          " >> $outfile
        echo "*                                                              " >> $outfile
        echo "*** END EMAIL SUMMARY ***                                      " >> $outfile

        `mail -s "Mobius Printer Down Alert!" "email1,email2" < $outfile`
    fi  
    let c=$(( c + 1 ))
done
exit