String 转换输入文件中的字符串

我在Unix上有一个文本文件

file1.txt

。我想生成另一个文件

file2.txt

，在该文件中，我更改了具有此格式的所有行组（取自多项选择题考试）

到

我怎么能这么做

编辑：例如

What is the value of three plus five?
a. six
b. seven
c. eight

This line is not so relevant.
blah blah

What is the capital of England?
a. London
b. Birmingham
c. New York

应将其转换为

What is the value of three plus five?
six seven eight

This line is not so relevant.
blah blah

What is the capital of England?
London Birmingham New York    

---

这一行应该适合您：

 awk '{if($0~/^[a-z]\. /){gsub(/^[a-z]\. /,"");printf "%s ",$0;s=1;next;}else{if(s)print "";print $0;s=0}}' file1

试验

---

你的输入完成了吗？那么文件2将只包含一行？把所有的[…]连在一起？file1中的“组”看起来如何？@Kent抱歉，我的描述似乎不清楚。请看我的例子。

What is the value of three plus five?
six seven eight

This line is not so relevant.
blah blah

What is the capital of England?
London Birmingham New York    

 awk '{if($0~/^[a-z]\. /){gsub(/^[a-z]\. /,"");printf "%s ",$0;s=1;next;}else{if(s)print "";print $0;s=0}}' file1

kent$  cat exam
What is the value of three plus five?
a. six
b. seven
c. eight

This line is not so relevant.
blah blah

What is the capital of England?
a. London
b. Birmingham
c. New York

kent$  awk '{if($0~/^[a-z]\. /){gsub(/^[a-z]\. /,"");printf "%s ",$0;s=1;next;}else{if(s)print "";print $0;s=0}}' exam
What is the value of three plus five?
six seven eight 

This line is not so relevant.
blah blah

What is the capital of England?
London Birmingham New York