如何实现打印关键字所在行及其上一行

lil33

sed -n 'n;/nihao/p'

grep nihao -B1 yourfile

都可行，谢谢各位老大

where27

回复 1# lil33

1. awk '/nihao/{print t"\n"$0}{t=$0}' file

复制代码

infernor

sed -n 'N;/nihao/P'

这种貌似有点小问题
[infernor@redhat sh]$ cat urfile
nihaodddd
ddddddd
dddddddddddddd
sfse2ijefjsjk..sfs..
weoiruoi121321sfioois
123213nihao2dsfjslk
sdfjsjfdslksj
sdjflksjdlfjsdjfksjlkfjlds
nihaoewiw112931
ksjfdlkdsj

[infernor@redhat sh]$ sed -n 'N;/nihao/p' urfile
nihaodddd
ddddddd
weoiruoi121321sfioois
123213nihao2dsfjslk
nihaoewiw112931
ksjfdlkdsj