[SOLVED] awk command to split filename based on substring

Issue

I have a directory in that file names are like

Abc_def_ijk.txt-1
Abc_def_ijk.txt-2
Abc_def_ijk.txt-3
Abc_def_ijk.txt-4
Abc_def_ijk.txt-5
Abc_def_ijk.txt-6
Abc_def_ijk.txt-7
Abc_def_ijk.txt-8
Abc_def_ijk.txt-9

I like to divide into 4 variables as below

v1=Abc_def_ijk.txt-1,Abc_def_ijk.txt-5,Abc_def_ijk.txt-9
V2=Abc_def_ijk.txt-2,Abc_def_ijk.txt-6
V3=Abc_def_ijk.txt-3,Abc_def_ijk.txt-7
V4=Abc_def_ijk.txt-4,Abc_def_ijk.txt-8

If no of files increase it will goto any of above variables. I'm looking for awk one liners to achieve above.

Solution

I would do it using GNU AWK following way, let file.txt content be

Abc_def_ijk.txt-1
Abc_def_ijk.txt-2
Abc_def_ijk.txt-3
Abc_def_ijk.txt-4
Abc_def_ijk.txt-5
Abc_def_ijk.txt-6
Abc_def_ijk.txt-7
Abc_def_ijk.txt-8
Abc_def_ijk.txt-9

then

awk '{arr[NR%4]=arr[NR%4] "," $0}END{print substr(arr[1],2);print substr(arr[2],2);print substr(arr[3],2);print substr(arr[0],2)}' file.txt

output

Abc_def_ijk.txt-1,Abc_def_ijk.txt-5,Abc_def_ijk.txt-9
Abc_def_ijk.txt-2,Abc_def_ijk.txt-6
Abc_def_ijk.txt-3,Abc_def_ijk.txt-7
Abc_def_ijk.txt-4,Abc_def_ijk.txt-8

Explanation: I store lines in array arr and decide where to put given line based on numer of line (NR) modulo (%) four (4). I do concatenate to what is currently stored (empty string if nothing so far) with , and content of current line ($0), this result in leading , which I remove using substr function, i.e. starting at 2nd character. (tested in GNU Awk 5.0.1)

Answered By - Daweo