shell学习

学习shell编程，简单的写了一个shell脚本。

这里有一个简单的shell教程：

 

#!/bin/bash
# this is shell script test file ,just for study

#1. if and test
if test -f shell.sh
then
    echo -e "\n Hello shell \n"
else
    echo -e "\n No shell.sh file \n"
fi

#another test
if [ -f shell.sh ]
then
    echo -e "\n Hello shell \n"
else
    echo -e "\n No shell.sh file \n"
fi

#2. for loop and echo
for var in 1 2 3 "bash shell "
do
    echo -n $var
done
echo -e

for var in 1 2 3 "bash shell" # -n -e diff
do
    echo -e $var
done

for var in 1 2 3 "bash shell" # -n -e diff
do
    printf $var
done
echo -e

#3. while
while [ "$0 != "untuntu" " ]
do
    echo -e "while loop"
    break
done

#4. input
echo -n "Please input usename :"
read usename

echo -n "Please input password :"
read password

case $password in
    y|yes|Y|YES) echo -e "$usename login";;
    n|no|N|NO) echo -e "password error";;
    *) echo -e " "
esac

#5. math and compare
#-eq 等于 -ne 不等于 -gt 大于
#-lt 小于 -le 小于等于 -ge 大于等于

sum=0
i=0
while [ $i -le 100 ]
do
    let sum=$sum+$i
    let i=i+1
done
echo -e "sum=$sum"