comparing variables in awk array

Shell Programming and Scripting
1

Hi,

I am trying to sort and display the below(like) input using awk command:

Input:
------
0;A
4;A
5;A
33;A
45;A
0;B
4;B
5;B
33;B
45;B

Output (desired):
-------

A 0;4;5;33;45
B 0;4;5;33;45

I am using awk -F\; 'END { for (k in arr) print k FS arr[k] }{ arr[$2] = arr[$2] ? arr[$2] FS $1 : $1 }' file name to get the output. the output which i get after runnin this command is

A ;4;5;33;45 -- '0' is missing
B ;4;5;33;45 -- '0' is missing

i think awk is not displaying 0 for the first time when it compares it with the next element in the array.

Can any one of you help me out to find the solution for this.

2

so you are sorting the file first then giving it to the awk???

3

yes..the input which i have given is the sorted one...

4

then this will do ..

awk -F";" '{A[$2]=A[$2]$1FS}END{for(i in A){print i" "A}}' filename
5

It is wierd!

This also seems to work:

awk -F\; 'END { for (k in arr) print k FS arr[k] }{ arr[$2] = arr[$2] ? arr[$2] FS $1 : $1 "" }'

Seems awk sees the first zero and does "something". Turning the 0 into a string ($1 "") unconfuses it.

I'm sure it's not a bug, but it's odd behaviour.

6

Thanks Vidyadhar... Its working.. Can you explain me if you have any idea what was the problem in the command that i have used. it was not displaying or comparing only 0.