gerp -e和grep -E的区别

1. grep -e 只能传递一个检索内容   

   grep -e pattern1 -e pattern2 filename

   例如：

   $ grep -e Tech -e Sales employee.txt  
   100  Thomas  Manager    Sales       $5,000  
   200  Jason   Developer  Technology  $5,500  
   300  Raj     Sysadmin   Technology  $7,000  
   500  Randy   Manager    Sales       $6,000 

   2.grep -E 可以传递多个内容 ，使用 | 来分割多个pattern，以此实现OR操作

   grep -E 'pattern1|pattern2' filenam

    

例如：

$ grep -E 'Tech|Sales' employee.txt  
100  Thomas  Manager    Sales       $5,000  
200  Jason   Developer  Technology  $5,500  
300  Raj     Sysadmin   Technology  $7,000  
500  Randy   Manager    Sales       $6,000