shell 编程之 在解压文件时terminal 中动态显示指定符号

 话不多说，直接源码：

#!/bin/bash
# Version:      2014-10-31      test for shell
# Author:       qustdjx         http://blog.youkuaiyun.com/qustdjx 

TAR=(linux-2.6.35.4 patch-2.6.35 image rootfs-2.6.35 application)
top_dir=/usr/test

echo 'please wait for a while, it will take some time'
for (( x=0; x<=4; x++)) do
	echo "Extracting ${TAR[$x]}.tar.gz"
	tar --directory=$top_dir -zxf ${TAR[$x]}.tar.gz&
	pid=`echo $!`
	str="| / - \\"
	count=1
	while [ -d /proc/$pid ]
	do
		if [ $count == 4 ]; then
			count=1
		fi
		echo -e -n "\r"`echo $str | awk '{print $'$count'}'`
		count=`expr $count + 1`
		sleep 1
	done
	echo -e -n '\r'
done
echo 'untar sucessful!!'

运行之前确保，/usr/test 目录存在

root@ubuntu:~/test/# ./test.sh 
please wait for a while, it will take some time
Extracting linux-2.6.35.4.tar.gz
Extracting patch-2.6.35.tar.gz
Extracting image.tar.gz
Extracting rootfs-2.6.35.tar.gz
Extracting application.tar.gz
untar sucessful!!
这时你会看到 str 变量中的内容循环显示“|” “/” “-”，是不是有动态之感！！！（除此，你要解压的文件容量要大点，不然不用等待了）