JSON formatter in pure bash

jsonf.sh

#!/bin/bash
function jsonf() {
    file=$1    
    indent=0    
    while IFS= read -r -n1 char; do
        case $char in
            ("{" | "[") echo "$char"; ((indent+=4)); printf "%${indent}s";;
            ("}" | "]") echo ""; ((indent-=4)); printf "%${indent}s$char";;
            (",") echo "$char"; printf "%${indent}s";;
            (*) printf "%s" "$char";;
        esac
    done < <(sed -e 's/}/}\n/g' -e 's/{/{\n/g' $file)
}

jsonf $1