假设文件名是1.txt
cat 1.txt | grep bbbb | head -1 | awk 'print $1,$2,dddd'
sorry看错了你的需求,上面的只是把你需要的那一行打印出来了,应该用sed来插入,也很简单
sed -i 's/bbbb 1234/bbbb 1234 dddd/' 1.txt
试了一下,可以搞
[root@room1pc01 data]# cat aaa.txtx
aaaa
bbbb 1234
bbbb 5678
cccc
[root@room1pc01 data]# str=`grep bbbb aaa.txtx|head -1`;sed -i "/$str/s/$/ dddd/" aaa.txtx
[root@room1pc01 data]# cat aaa.txtx
aaaa
bbbb 1234 dddd
bbbb 5678
cccc