binary-safe file-to-ram, ram-to-file, in pure bash

bin_to_hex_to_bin.sh

#!/usr/bin/env bash
# file-to-ram, ram-to-file, in pure bash
# binary-safe including nulls, no external tools, no sub-shells
# Brian K. White b.kenyon.w@gmail.com

# read file binary to h[] hex pairs
ftoh () {
  local -i i= ;local x= LANG=C ;h=()
  while IFS= read -d '' -r -n 1 x ;do printf -v h[i++] '%02X' "'$x" ;done <$1
}

# write h[] hex pairs to file binary
htof () {
  local -i i= t=${#h[*]}
  while ((i<t)) ;do printf '%b' "\x${h[i++]}" ;done >$1
}

######################################################################
# main
typeset -a h=()

ftoh $1

# here you may manipulate h[] at will

htof $2