Bash - Awk sort -n not sorting

Question

awk '{for(i=1; i<=NF; i++) printf("%d ",$i)}' | sort -n

it reads a file like

55 89 33 20

and prints it out normally, not numerically sorted. Why?

Answer 1

sort works on a per-line basis, and printf doesn't append a newline by default, you need to specify it. So use:

awk '{for(i=1; i<=NF; i++) printf("%d\n",$i)}' | sort -n

This will print out your numbers on separate lines, if you want them to be in a single line again then you can pipe it to paste:

awk '{for(i=1; i<=NF; i++) printf("%d\n",$i)}' | sort -n | paste -s -d ' '

You can also just use print instead of printf, this will append the newline by default:

awk '{for(i=1; i<=NF; i++) print $i}' | sort -n