Simple bar chart generation with bash

bar.sh

#!/bin/bash
# make bar chart from $prog, $total, $n_seg as $1 $2 $3
# example:
# > ./bar.sh 25 100 12
# ███░░░░░░░░░

bar () {
    # $1 $2 $3 are progress total total_segments
    # shows progress/total using total_segments characters
    if [ $1 == "0" ] && [ $2 == "0" ]; then
        awk -v TOTSEG=$3 'BEGIN {
            for (s = 0; s < TOTSEG; s++) {
                printf "%s", "░";
            }
        }'
    else
        awk -v prog=$1 -v TOTAL=$2 -v TOTSEG=$3 'BEGIN {
            frac = prog / TOTAL;
            segs = frac * TOTSEG;
            segs_int = int(sprintf("%.0f", segs));
            for (s=0; s<segs_int; s++) {
                printf "%s", "█";
            }
            for (s=0; s<(TOTSEG - segs_int); s++) {
                printf "%s", "░";
            }
        }'
    fi
}

if [ -z $1 ]; then
  bar 25 100 40
  echo ""
else
  bar $1 $2 $3
  echo ""
fi