Using bash to read elements on a diagonal on a matrix and redirecting it to another file

Question

So, currently i have created a code to do this as shown below. This code works and does what it is supposed to do after I echo the variables:

a=`awk \'NR==2 {pri         


        

Answer 1

awk 'BEGIN {f=1} {print $f; f=f+1}' infile > outfile

Answer 2

An alternative using sed and coreutils, assuming space separated input is in infile:

n=$(wc -l infile | cut -d' ' -f1)
for i in $(seq 1 $n); do
  sed -n "${i} {p; q}" infile | cut -d' ' -f$i
done

Answer 3

You can replace your lines of awk with this one:

awk '{ for (i=1; i<=NF; i++) if (NR >= 2 && NR == i) print $(i - 1) }' file.txt

Tested input:

1 2 3 4 5 6 7 8 9 10
11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30
31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
51 52 53 54 55 56 57 58 59 60
61 62 63 64 65 66 67 68 69 70
71 72 73 74 75 76 77 78 79 80

Output:

11
22
33
44
55
66
77