ruby -e “puts File.open(‘/etc/passwd’).sort { |a,b| a.length b.length }”

;>)

awk ‘{print length, $0}’ /etc/passwd | sort -n | awk ‘{$1=”"; print $0 }’

You can put the length of the line into an associative array and sort it all from within awk. Interesting associative array play:

awk ‘{ arr[length $0] = $0 } END { for (len in arr) \
printf(“%d\t%s\n”, len, arr[len]) | “sort -n” }’ /etc/passwd | cut -f2-

In script form it’s a bit clearer:

#!/bin/bash
# awksort: sort the input by size

awk ‘{
arr[length $0] = $0
}
END {
for (len in arr)
printf(“%d\t%s\n”, len, arr[len]) | “sort -n”
}’ $* |

cut -f2-

Invoked with:

# awksort /etc/passwd