docs: add bash progress bar article

content/articles/2024/bash_printf/files/script4_progress.sh

@@ -0,0 +1,42 @@
+#!/usr/bin/env bash
+# shellcheck disable=2317
+PING_ITER=16
+PROGRESS_BAR_CHAR=(█ ▒)
+
+command() {
+    local -r host=${1?"first parameter must be an host"}
+    local -r iteration=${2?"second parameter must be an iteration number"}
+    local -r cmd=(ping -c "${iteration}" "${host}")
+
+    "${cmd[@]}"
+}
+
+draw_progressbar() {
+    local -r progress=${1?"progress is mandatory"}
+    local -r total=${2?"total is mandatory"}
+    local progress_segment
+    local todo_segment
+
+    printf -v progress_segment "%${progress}s" ""
+    printf -v todo_segment "%$((total - progress))s" ""
+    printf >&2 "%s%s\r" \
+        "${progress_segment// /${PROGRESS_BAR_CHAR[0]}}" \
+        "${todo_segment// /${PROGRESS_BAR_CHAR[1]}}"
+
+}
+
+parse_output() {
+    while read -r line; do
+        if [[ "$line" =~ icmp_seq=([[:digit:]]{1,}).*time=(.*) ]]; then
+            draw_progressbar "${BASH_REMATCH[1]}" "$PING_ITER"
+        fi
+    done
+}
+
+main() {
+    command "aquilenet.fr" "$PING_ITER" > >(parse_output)
+}
+
+main
+exit 0
+# [...]