Col returns the specified columns from each line in stdin

col

#!/usr/bin/bash
# Usage: col x x x 
# where x is a column number or + to mean all following columns
# 
# example: ls -al | col 6 7 9
# example: ls -al | col 2 7 +
# example: ls -al | col -1 

# Here is a fun use... interleave lines from logs from several containers in timestamp order
# docker-compose logs --tail='all' -t | col 3 1 + | sort | col 2 + 

column () { 
  local args=("awk '{ ")
  local last_index=0
  if (( $1 < 0 )) 
  then 
    args+=("printf \$(NF+1$1);")
    last_index="NF+1$1"
  else
    args+=("printf \$$1;")
    last_index=$1
  fi
  while [[ ! -z "$2" ]]
  do
    args+=('printf " ";')
    shift
    if [ ! $1 = "+" ]; then
      if (( $1 < 0 )) 
      then 
        args+=("printf \$(NF+1$1);")
        last_index="NF+1$1"
      else
        args+=("printf \$$1;")
        last_index=$1
      fi
    else
      args+=('for(i='$last_index'+1;i<=NF;++i){printf " ";printf $i;}')
    fi
  done

  args+=("; print \"\"}'")

  eval "${args[@]}"
  #echo "${args[@]}"
}

column $*

negative index numbers count from the back of the line.