找出指定分隔符中间的字符串

【问题】

Hi friends, I want to ask a question:
how can I extract all the text between two given strings str1 and str2? The returned results should be seperated by something such as a space line.
For example, my "input.txt" is:
abdeb .....  str1 aaaaaaaaaaaaaaaaa str2 bbbbbbbbbbbb str1 cccccccccccccccccc str2 ddddddddddddddddd ....

Then my output.txt should be:
aaaaaaaaaaaaaaaaa
cccccccccccccccccc 
Note that the text between str1 and str2 could be any length.
I think regular expression and egrep should be able to achieve this, but I am not familar with them. Hope anyone can help. Thanks! 

【回答】

       正则表达式可以解决这种问题,只是对于初学者来说太抽象不太容易掌握。这种较简单的情况也可以试试采用SPLSPL既支持正则表达式,也支持直观的函数,比如:pos(取位置)、mid(按位置截取)。比如这个问题的脚本如下:


A

1

=file("D:\\input.txt").read().split("str2")

2

=A1.select(pos(~,"str1"))

3

=A2.(mid(~,pos(~,"str1")+4))

4

=file("D:\\output.txt").write(A3)

A1:读取文本串,并按照”str2”分隔成序列

A2:选取含有”str1”子串的成员

A3:从A2的每个成员中截取”str1”后面的字符串

A4:将A3写入output.txt