docs: add bash progress bar article

content/articles/2024/bash_printf/files/script7_sigwinch.sh

@@ -0,0 +1,69 @@
+#!/usr/bin/env bash
+# shellcheck disable=2317
+PING_ITER=64
+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}")
+
+    "${cmd[@]}"
+}
+trap change_column_size WINCH
+
+draw_progressbar() {
+    local -r progress=${1?"progress is mandatory"}
+    local -r total=${2?"total elements is mandatory"}
+    local -r info_segment=${3:""}
+    local progress_segment
+    local todo_segment
+
+    local -r bar_size=$((COLUMNS - ${#info_segment}))
+    local -r progress_ratio=$((progress * 100 / total))
+    local -r progress_segment_size=$((bar_size * progress_ratio / 100))
+    local -r todo_segment_size=$((bar_size - progress_segment_size))
+
+    printf -v progress_segment "%${progress_segment_size}s" ""
+    printf -v todo_segment "%${todo_segment_size}s" ""
+
+    printf >&2 "%s%s%s\r" \
+        "${info_segment}" \
+        "${progress_segment// /${PROGRESS_BAR_CHAR[0]}}" \
+        "${todo_segment// /${PROGRESS_BAR_CHAR[1]}}"
+
+}
+
+parse_output() {
+    trap change_column_size WINCH
+    while read -r line; do
+        if [[ "$line" =~ icmp_seq=([[:digit:]]{1,}).*time=(.*) ]]; then
+
+            draw_progressbar \
+                "${BASH_REMATCH[1]}" \
+                "$PING_ITER" \
+                "Ping in progress (time: ${BASH_REMATCH[2]}) "
+        elif [[ "$line" =~ ^PING(.*\(.*\)).* ]]; then
+            printf "Launch ping command to %s with %d iterations\n" \
+                "${BASH_REMATCH[1]}" \
+                "$PING_ITER"
+        elif [[ "$line" =~ .*packets\ transmitted.* ]]; then
+            printf >&2 "\033[0K\r"
+            printf "%s\n" "$line"
+        fi
+    done
+}
+
+change_column_size() {
+    printf >&2 "%${COLUMNS}s" ""
+    printf >&2 "\033[0K\r"
+    COLUMNS=$(tput cols)
+}
+
+main() {
+    COLUMNS=$(tput cols)
+    command "aquilenet.fr" "$PING_ITER" > >(parse_output)
+}
+
+main
+exit 0