awk search syntax

Shell Programming and Scripting
1

I need help with understanding awk search feature.

Here I am trying to search by 4th field in this file:

$ cat xx
471013,A20,asd,100,FEATURE UNKNOWN
171014,A22,sdf,101,FEATURE WITH SUB-ELEMENT
172822,20X,xcv,102,SUB-ELEMENT
101102,22X,asd,103,CODED

When I try the search feature I get nothing:

$ awk -F, '/$4 ~ "101"/{print}' xx        

$

When I just use IF statement it works as expected:

$ awk -F, '{ if($4 == 101)print; }' xx
171014,A22,sdf,101,FEATURE WITH SUB-ELEMENT
$

Please help me understand what do I do wrong in using the search // syntax
Thanks

2

Hi
This way you won't succeed too

awk -F, '{ if(/$4 ~ "101"/)print; }' xx
3

In awk , /.../ is (sort of) a regex constant. man awk :

So, your expression /$4 ~ "101"/ will try to match exactly this string : $4 ~ "101" - which it won't find in your sample file.
Try

awk -F, '$4 ~ /101/' xx

which might do exactly what you targeted for.

2 Likes
4

Thank you RudiC