while、if、break用法及多进程用法

 

这个脚步是判断aimeserverd.nginx是否启动成功，如果失败等60秒重新启动，最多试10次。

 

/etc/init.d/aimeserverd.nginx start >> result.${date}
returnaimestat=$?

aim_num=0
while [ $aim_num -lt 10 ]
do
   if [ $returnaimestat -ne 0 ]
        then
        sleep 60
        /etc/init.d/aimeserverd.nginx start >> result.${date}
        returnaimestat=$?
        echo "aimeserverd  stat $returnaimestat">>result.${date}
        else
        break
   fi
        let aim_num+=1
done

 

脚本二

放后台下载，最多只能运行50个下载进程。

#!/bin/bash
cd /mnt/mediadisk2
for i in `seq 8 |awk  '{printf "0%d\n",$0}'`
  do
  cd /mnt/mediadisk2/$i
  for file in `cat /mnt/mediadisk2/$i.txt`
       do
       wget $file  > /dev/null 2>&1 &
       if [ $? -eq  0 ]
       then
       echo "$file is ok" >> /mnt/mediadisk2/$i.log
       pscount=$(ps -ef |grep -v "grep" | grep -c wget)
       until [ $pscount -le 50 ]
                do
                sleep 2
                   pscount=$(ps -ef |grep -v "grep" | grep -c wget)
                done
        done
done