使用awk进行字符串匹配

Question

I have a tab separated file that has rows like this:

field1 field2 field3 field4 field5 field6
1 abc 2 word:add,word:remove text string
2 xyz 2 word:replace,word:modify msg string
3 lmn 1 word:add msg numeric
4 cncn 2 phone:add,phone: remove msg numeric
5 lmn 2 word:add msg text

I want to write an awk program/oneliner that gives me the rows where

field3 ==2 and field4 contains either "add" or "remove"

In other words it should have first filtered out these and,

1 abc 2 word:add,word:remove text string
2 xyz 2 word:replace,word:modify msg string
4 cncn 2 phone:add,phone:remove msg numeric
5 lmn 2 word:add msg text

In the second step should have filtered out these

1 abc 2 word:add,word:remove text string
4 cncn 2 phone:add,phone:remove msg numeric    
5 lmn 2 word:add msg text

I can get the first step right using : cat test.tsv | awk -F '\\t' '$3 == 2' cat test.tsv | awk -F '\\t' '$3 == 2'

How do I match the substrings for the second part? Thanks in advance

Answer 1

You could match the field using ~ :

awk -F '\t' '$3==2 && $4 ~ /add|remove/' filename

would produce the desired result:

1 abc 2 word:add,word:remove text string
4 cncn 2 phone:add,phone: remove msg numeric
5 lmn 2 word:add msg text

Quoting from the manual:

   ~ !~        Regular  expression match, negated match.  NOTE: Do not use
               a constant regular expression (/foo/) on the left-hand side
               of  a  ~  or !~.  Only use one on the right-hand side.  The
               expression /foo/ ~ exp has  the  same  meaning  as  (($0  ~
               /foo/) ~ exp).  This is usually not what was intended.