使用awk处理带标签文本

使用awk处理带标签文本

 

 假设有"123<em>abc</em>456<em>def</em>789<em>ghi</em>"这么一个字符串

题中的字符串，要截取长度5，则返回的字符串应该为:123ab,要截取长度8，应返回123<em>abc</em>45。

附：

1 <em>和</em>标记不得计算在长度之内。

2 截取后的字符串，要保留原有<em>标签，不过如果最后有一个标签没有闭合，则去掉其开始标签。

 

代码：如下

#!/bin/bash

a='123<em>abc</em>456<em>def</em>789<em>ghi</em>'

echo "test text is '$a'"

read -p "please input a number little than `echo $a|awk '{gsub("<em>|</em>","",$0);printf length($0)}'`: " num

 

echo $a | awk -vnum="$num" -vFS='</em>' '{for(i=1;i<=NF;i++){orisum=sum;sum+=length($i)-4;if(sum<=num){strlist=strlist ~ /./ ? strlist""FS""$i : $i}else{sub("<em>","",$i);strlist=strlist ~ /./ ? strlist""FS""substr($i,1,num-orisum) : substr($i,1,num-orisum);break}}print strlist}'

 

测试结果：

 

[root@localhost ~]# bash 1.sh 

test text is '123<em>abc</em>456<em>def</em>789<em>ghi</em>'

please input a number little than 18: 2

12

[root@localhost ~]# bash 1.sh 

test text is '123<em>abc</em>456<em>def</em>789<em>ghi</em>'

please input a number little than 18: 5

123ab

[root@localhost ~]# bash 1.sh 

test text is '123<em>abc</em>456<em>def</em>789<em>ghi</em>'

please input a number little than 18: 7

123<em>abc</em>4

[root@localhost ~]# bash 1.sh 

test text is '123<em>abc</em>456<em>def</em>789<em>ghi</em>'

please input a number little than 18: 10

123<em>abc</em>456d

[root@localhost ~]# bash 1.sh 

test text is '123<em>abc</em>456<em>def</em>789<em>ghi</em>'

please input a number little than 18: 9

123<em>abc</em>456

[root@localhost ~]# bash 1.sh 

test text is '123<em>abc</em>456<em>def</em>789<em>ghi</em>'

please input a number little than 18: 14

123<em>abc</em>456<em>def</em>78

[root@localhost ~]# bash 1.sh 

test text is '123<em>abc</em>456<em>def</em>789<em>ghi</em>'

please input a number little than 18: 17

123<em>abc</em>456<em>def</em>789gh

[root@localhost ~]# bash 1.sh 

test text is '123<em>abc</em>456<em>def</em>789<em>ghi</em>'

please input a number little than 18: 18

123<em>abc</em>456<em>def</em>789<em>ghi</em>

[root@localhost ~]#