如何在egrep中使用varible作为搜索字符串

Question

我想使用egrep从文件执行多字符串搜索，但是使用变量来存储搜索字符串值。这将帮助我以编程方式更改搜索字符串。例如： -

SEARCHSTRING='typesetting industry|printer took|specimen'
cat /tmp/input.file|egrep $SEARCHSTRING > /tmp/output.file

input.file内容：

*Lorem Ipsum is simply dummy text of the printing and typesetting industry.  
Lorem Ipsum has been the industry's standard dummy text ever since the  
1500s, when an unknown printer took a galley of type and scrambled it to  
make a type specimen book. It has survived not only five centuries,   
but also the leap into electronic*  

output.file内容（预期）：

*Lorem Ipsum is simply dummy text of the printing and typesetting industry.  
1500s, when an unknown printer took a galley of type and scrambled it to  
make a type specimen book. It has survived not only five centuries,*   

请帮忙

Answer 1

双引号变量，也使用grep -E而不是egrep

egrep  "$SEARCHSTRING" inputfile
Lorem Ipsum is simply dummy text of the printing and typesetting industry.
1500s, when an unknown printer took a galley of type and scrambled it to
make a type specimen book. It has survived not only five centuries,