Pure bash equivalent to python's os.path.commonpath

common_path.bash

#!/usr/bin/env bash


# takes paths in argv, assumes they are in absolute, as if it was outputed by `pwd`
common_path() {
  if [ "$(printf '%s\n' "${@}" | sort | uniq | wc -l)" -eq 1 ]; then
    printf %s "${1}"
    return
  fi

  local n=2
  while [ "$(printf '%s\n' "${@}" | cut -f-"${n}" -d'/' | sort | uniq | wc -l)" -eq 1 ]; do
    if [ ${n} -gt 8 ]; then
      break
    fi
    n=$((n + 1))
  done

  local result="$(printf '%s' "${1}" | cut -f-$((n - 1)) -d'/')"
  if [ -z "${result}" ]; then
    printf '/'
  else
    printf %s "${result}"
  fi
}


common_path "${@}"