背景：使用shell脚本，使用sed将字符/替换为\。

一直报错，搜了下资料，终于好了，记录下

错误1：

#!/bin/bash

var="/media/sf_Project/self/smarty-frame/application/ApiLoveHouse/Controllers"
var=${var#*application}
string=$var | sed 's#\/#\\#g'
echo $string

错误2：

#!/bin/bash

var="/media/sf_Project/self/smarty-frame/application/ApiLoveHouse/Controllers"
var=${var#*application}
string=`$var | sed 's:\/:\\:g'`
echo $string

错误3：

#!/bin/bash

var="/media/sf_Project/self/smarty-frame/application/ApiLoveHouse/Controllers"
var=${var#*application}
string=`echo $var | sed 's:\/:\\:g'`
echo $string

正确姿势：

var="/media/sf_Project/self/smarty-frame/application/ApiLoveHouse/Controllers"
var=${var#*application}
echo $var | sed 's:\/:\\:g'
string=$(echo $var | sed 's#\/#\\#g')
echo $string

返回

[root@vbox-nginx shell_command]# ./mkdemo.sh 
\ApiLoveHouse\Controllers
\ApiLoveHouse\Controllers