grep：输出两个匹配

Question

以下命令仅返回file2中的匹配项。

grep -f file1 file2 

如何从file2的第二个匹配之后的第一个文件（file1）打印匹配行？

Answer 1

awk 'NR==FNR{res[$0]; next} 
{ 
    found = 0 
    for (re in res) { 
     if ($0 ~ re) { 
      print "found:", re 
      found = 1 
     } 
    } 
} 
found 
' file1 file2