1. uids.txt
111
222
333
2. log.txt
aaa 111
qqq 333
www 777
fff 888
ggg 444
ppp 111
3. 脚本
awk 'NR==FNR{ uids[$1]=$1 } NR>FNR { if(($2 in uids)) {print $0} }' uids.txt log.txt
4. 结果
aaa 111
qqq 333
ppp 111
6. 拓展阅读：
http://bbs.chinaunix.net/forum.php?mod=viewthread&tid=2307853&page=1#pid15547885
