【BASH】bash shell的使用实例

?  读取文件的时间

#!/bin/bash

for file in `ls /root`

do    

stat $file>1.txt

sed -n "7p" 1.txt>2.txt

usetime= awk -F ":" ‘{print $2}‘ 2.txt

echo "time="$file $usetime

done      

?  读取文件的每行while语句。

cat afile | while read oneline

do

             echo $oneline

done

?  读取文件的每行for语句。

for i in `cat afile`

do

echo $i

done

?  自己主动加入用户

useradd test

passwd test<<eof

111111

111111

eof

?  自己主动杀死进程

ps -a | grep ‘‘ | awk ‘{print $1}‘ | xargs -i kill 9 {}

?  保留七天的文件

#! /bin/bash

for file in `ls /orabak`

do

    if [[ ${file:0:2} == "db" ]];then

          fdate=${file:10:8}

          mydate=`date +%Y%m%d -d "-7 day"`

          if [[ $fdate < $mydate ]];then

               rm -rf $file;

          else

               echo $file;

          fi

      else

          fdate=${file:12:8}

         mydate=`date +%Y%m%d -d "-7 day"`

          if [[ $fdate < $mydate ]];then

               rm -rf $file;

          else

               echo $file;

          fi

       fi

done

?  查看表的字段

su - oracle << BO

sqlplus / as sysdba<<EOF

desc user_tables;

exit;

EOF