Progress bar in a bash script

progress-bar-bash

#!/usr/bin/env bash

# https://ghostty.org/docs/vt/csi/el
# https://gist.github.com/fnky/458719343aabd01cfb17a3a4f7296797

WIDTH=100
HEIGHT=100
BATCHSIZE=5

bar() {
    local iter=$1
    local max=$2
    local w=$max/100*2+5+5
	local bar_width=$WIDTH-w
    local per=$((iter * 100 / max))
	local bar=$((per * bar_width / 100))
	local max_padd=${#max}
	local frmt="%${max_padd}d"
	local pad_iter=$(printf $frmt "$iter")
	local pad_per=$(printf "%3d" "$per")
    local suf=" $pad_per% ($pad_iter/$max)"
    local s=''
    local x
	for ((x=0;x<$bar;x++)) {
        s+='▓'
    }
	for ((x=$bar;x<$bar_width;x++)) {
        s+='░'
    }
    s+="$suf"

	printf '\e7' # save cursor location
	printf '\e[%d;%dH' "$LINES" 0 # move to last line
	printf '\e[0K' # clear the line
	printf '%s' "$s" # print content
	printf '\e8' # restore cursor location
}

process_files() {
	local files=("$@")
	for file in "${files[@]}"; do
		echo " = $file"
	done
    sleep 0.1
}

init-term() {
	WIDTH=$COLUMNS
	HEIGHT=$((LINES-1))
	printf '\n' # 
	printf '\e7' # save cursor location
	printf '\e[%d;%dr' 0 "$HEIGHT" # set scrollable region
	printf '\e8' # restore cursor location
	printf '\e[1A' # move cursor up
}

deinit-term() {
	printf '\e7' # save cursor location
	printf '\e[%d;%dr' 0 "$LINES" # reset scrollable region
	printf '\e[%d;%dH' "$LINES" 0 # move to last line
	printf '\e[2K' # clear the line
	printf '\e8' # restore cursor location
}

main() {
	shopt -s globstar nullglob checkwinsize
	(:) # trigger get window size
	trap deinit-term exit
	trap init-term winch
	init-term

	local files=(./**/*cache)
    local amount=${#files[@]}
    local i
	for ((i = 1; i <= $amount; i+=BATCHSIZE)) {
        bar "$i" "$amount"
		process_files "${files[@]:i:BATCHSIZE}"
    }
	bar "$amount" "$amount"
}

main