[SOLVED] awk array is created but elements are missing

awk array is created but elements are missing

I have this sample file

userX   2020    start   id1
userY   2005    stop    id2
userZ   2006    start   id3
userT   2014    stop    id1
userX   2010    stop    id1

I want to create an array where year value $2 is element for every unique user-id pair $1$4 with given condition $3=="stop". For example arr[userXid1]=2010 and arr[userTid1]=2014

my code:

awk '{if($3=="stop") arr[$1$4]=$2} END{print arr[userXid1]}' log

expected output:

But this prints empty line. when I print length(arr) it gives 3 which makes sense. but $2 values are not there and I can't figure out why. Any help is appreciated.

awk '{if($3=="start") arrstart[$1,$4]=$2; else if($3=="stop") arrstop[$1,$4]=$2 fi; next} END{for(i in arrstop) if(arrstart[i]>arrstop[i]) print i}' SUBSEP=':' log

addition: final code, nothing to do with question.

Solution

You may use this awk:

awk '$3 == "stop" {arr[$1,$4] = $2} END {print arr["userX","id1"]}' file

2010

To print all unique values use:

awk '$3 == "stop" {arr[$1,$4] = $2}
END {for (i in arr) print i, arr[i]}' SUBSEP=':' file

userY:id2 2005
userT:id1 2014
userX:id1 2010