C高级--day3(shell中的输入、命令置换符、数组、算数运算、分支结构)

 

#!/bin/bash
p=`ls ~/ -l | grep "^-" | wc -l`
q=`ls ~/ -l | grep "^d" | wc -l`
echo "普通文件个数：$p"
echo "目录文件个数：$q"

#!/bin/bash
read file
pos=`expr index $file \.`
str=`expr substr $file $((pos+1)) 2`
if [ $str == "sh" ]
thenif [ -x $file ]then echo "$file是脚本文件"bash $fileelsechmod u+x $filefi
elseecho "$file不是脚本文件"
fi

 

#!/bin/bash
read file1 file2
if [ $file1 -nt $file2 ]
thenecho "file1比file2更新"
elif [ $file1 -ot $file2 ]
then  echo "file2比file1更新"
fi

#!/bin/bash
read user
name=`grep -q $user /etc/passwd`
if [ $? -eq 0 ]
thenecho "$user用户存在"
elseecho "$user用户不存在"sudo adduser $user
fi

  

 

#!/bin/bash
read score
if [ $score -gt 90 -a $score -le 100 ]
thenecho "A等级"
elif [ $score -gt 80 -a $score -le 90 ]
then echo "B等级"
elif [ $score -gt 70 -a $score -le 80 ]
then echo "C等级"
elif [ $score -gt 60 -a $score -le 70 ]
then echo "D等级"
elif [ $score -gt 0 -a $score -le 60 ]
then echo "不合格"
elseecho "输入的成绩不合法，请重新输入"
fi

 

#!/bin/bash
name=`whoami`
arr=( $name `id -u $name` `echo $PATH`)
echo ${arr[*]}

 

 

#!/bin/bash
num=`ls -d /etc/[Pp]* | wc -l`
echo $num