Bash 1 bit image viewer

readbinary.sh

#!/bin/bash
# bash 1 bit image viewer
# Usage: ./readbinary.sh filename linelength
# Try echo '\x07\xe0\x1c\x38\x32\x4c\x30\x0c\x33\xcc\x18\x18\x07\xe0' > onebitimage; ./readbinary.sh onebitimage 16

# `xxd -b` gets binary dump of file,
# first `awk` matches part after line number,
# second `awk` strips ascii interpretation,
# `tr` strips space, period, linebreak
binary=$(xxd -b $1 | awk 'match($0, /.+:/) {print substr($0, RLENGTH+1)}' | awk 'match($0, /  /) {print substr($0, 0, RSTART)}'| tr -d ' .\n')
i=0
# `grep` splits each character on separate line,
# `read` iterates over lines
grep -o . <<< $binary | while read -r character; do
    # write '.' for 1
    if [ "$character" == '1' ]; then 
        echo -ne "m"
    # write ' ' for 0
    else
	echo -ne " "
    fi

    # increment counter
    i=$((i+1))
    # linebreak every nth character
    if [ $((i%$2)) == '0' ]; then
	echo ''
    fi

done