Compare two column in two different files using awk - awk

Question

I have two files as given below
file1
1|a
2|b
3|c
4|d
5|e
6|g
7|h
8|i
file2
2
3
expected output using awk in linux
1|a
4|d
5|e
6|g
7|h
8|i
Tried below but not getting expected op
awk '{k=$1 FS $2} NR!=FNR{a[k]; next} !(k in a)' file1 file2
expected output using awk in linux
1|a
4|d
5|e
6|g
7|h
8|i

Answer 1

We have to set different FS for both Input_file(s) since once Input_file is PIPE(|) delimited and other is not, could you please try following. This will only print those lines which are NOT in Input_file2 and present in Input_file1.
awk 'FNR==NR{a[$0];next} !($1 in a)' Input_file2 FS="|" Input_file1
Output will be as follows.
1|a
4|d
5|e
6|g
7|h
8|i
Explanation: Adding explanation for above command.
awk ' ##Starting awk program from here.
FNR==NR{ ##Checking condition FNR==NR which will be TRUE when Input_file2 is being read.
a[$0] ##Creating an array named a whose index is $0 here.
next ##next function is awk out of the box function which skips all further statements from here onward.
} ##Closing BLOCK for FNR==NR condition here.
!($1 in a) ##Checking condition if $1 is NOT present in Input_file1, this condition will be executed when Input_file named Input_file1 is being read.
' Input_file2 FS="|" Input_file1 ##Mentioning Input_file2 name then setting FS as pipe and mentioning Input_file1 here.