基于匹配模式的字符串替换

给字符串赋值

$ str="android" 

1 替换字符串

$ echo ${str/a/A}

Android

$ echo ${str/d/D}

anDroid

2 替换全部字符

$ echo ${str//d/D}

anDroiD

3 替换首字符

$ echo ${str/#a/google designs } 
google designs ndroid

4 替换尾字符

$ echo ${str/%d/d make by google}

android make by google