Shell脚本来自第一个indexof substring

Question

我想在bash中完成以下伪代码的等价物(a和b都是我脚本的输入):

String a = "some long string";
String b = "ri";
print (a.substring(a.firstIndexOf(b), a.length()); //prints 'ring'

我怎样才能在shell脚本中执行此操作？

Answer 1

你可以做:

$ a="some long string"
$ b="ri"
$ echo $a | grep -o "$b.*"
ring

Answer 2

尝试:

    $ a="some long string"
    $ b="ri"

    $ echo ${a/*$b/$b}
    ring

    $ echo ${a/$b*/$b}
    some long stri