Using bash to sort data horizontally

Question

I have a file full of data in columns

sarah mark john
10    20   5
x     y    z 

I want to sort the data so the columns stay intact but the

Answer 1

Coming from a duplicate question, this would sort the columns by the first row:

#!/bin/bash

input="$1"

order=$((for i in $(head -1 $input); do echo $i; done) | nl | sort -k2 | cut -f1)

grep ^ $input | (while read line
  do
    read -a columns <<< "${line%"${line##*[![:space:]]}"}"

    orderedline=()
    for i in ${order[@]}
    do
      orderedline+=("${columns[$i - 1]}")
    done
    line=$(printf "\t%s" "${orderedline[@]}")
    echo ${line:1}
  done)

To sort by second row, replace head -1 $input with head -2 $input | tail -1. If the sort should be numeric, put in sort -n -k2 instead of sort -k2.