Linux Shell 笔记二(循环结构)

程序12：类似java 里面的switch case
[root@localhost scripts]# cat sh12.sh
read -p "input comand:" command
case $command in
"fix")
echo "fix system"
;;
"fuck")
echo "fuck you"
;;
*)
echo "what a stupid man!ex>$0 some word"
esac
exit 0

程序13：简单简单，超级简单的一个函数
[root@localhost scripts]# cat sh13.sh
function printit()
{
echo -n "Your choice is $1"
}
#$1为控制台输入的第二个参数
printit 1;echo $1 | tr 'a-z' 'A-Z'

程序14:until do done
[root@localhost scripts]# cat sh14.sh
until [ "$yn" = "yes" ] || [ "$yn" == "YES" ]
do
read -p "please input yes/to stop this program:" yn
done

程序15：while do done
[root@localhost scripts]# cat sh15.sh
s=0
i=0
while [ "$i" != "100" ]
do
i=$(($i+1))
s=$(($s+$i))
done
echo "number of 1+2+3+...+100=$s"
程序16：for do done
[root@localhost scripts]# cat sh16.sh
s=0
for((i=1;i<=100;i=i+1))
do
s=$(($s+$i))
done
echo $s
exit 0

程序17:for do done(2)
[root@localhost scripts]# cat sh17.sh
for animal in dog cat elephant
do
echo "there are ""$animal"
done
exit 0

程序18：利用 for do done查找某一个目录下面的文件权限信息
[root@localhost scripts]# cat sh18.sh
read -p "input a directory:" dir
if [ "$dir" == "" ] || [ ! -d "$dir" ]; then
echo "The $dir is not exist in the system"
exit 1
fi
echo `ls $dir`
filelist=`ls $dir`
for filename in $filelist
do
perm="";
test -r "$dir/$filename" && perm="$perm readable"
test -w "$dir/$filename" && perm="$perm writable"
test -x "$dir/$filename" && perm="$perm execuatable"
echo "The file $dir/$filename's permission is $perm"
done