linux - java string regex head not contains -

i have string :

[root@slave1 ~]# test -d /root/workspace/servers || echo not found [root@slave1 ~]# test -d /root/workspace/servers || echo not found not found [root@slave1 ~]# test -d /root/workspace/servers || echo not found [root@slave1 ~]# test -d desktp || echo not found not found 

and want find word not found without echo @ first

as can see , in string , there 2 match

how can ??

use negative lookbehind.

"(?<!\\becho )not found(?=\\s|$)" 

you use same regex in grep.

grep -op '(?<!\becho )not found(?=\s|$)' file 

(?<!\becho ) - don't lookafter echo<space>

not found(?=\s|$) - match not found strings must followed space or line end.