Shell 三个小程序

运行环境：Ubuntu12.04  bin/bash

1.比较两个数的大小

#!bin.bash
#script4.4.sht
echo "Enter the first integer:"
read first 
echo "Enter the second integer:"
read second
if [ "$first" -gt "$second" ]
    then 
        echo  "$first is greater than $second"
    elif [ "$first" -lt "$second" ]
then
    echo "$first is less than  $second"
fi
 

2.判断当前用户是否和输入的用户名一致

#!bin/bash
#script4.3.sht
   echo  -n  "Enter your login name: "
   read name
   if [ "$name" = "$USER" ];
   then 
       echo "Hello,$name,how are you today?"
   else
       echo "If you are not user,who are you?"
   fi

3.求若干数中的最小值

#!bin/bash
#script 4.8.sht
smallest=10000
for i in 12 5 18 58 -3 80
do 
if test $i -lt $smallest
then 
    smallest=$i
fi 
done 
echo " The smallest number is :$smallest"