additional/bash/bg.sh: Script to provide example of starting multiple jobs at background and waiting for them to finish

Signed-off-by: Marian Marinov <[email protected]>

Author: hackman

additional/bash/bg.sh

@@ -0,0 +1,26 @@
+#!/bin/bash
+
+# Example script of staring and waiting on a number of tasks at background
+
+cmd='sleep 5'
+max_threads=3
+for i in {1..5}; do
+	procs=()
+	for m in $(seq 1 $max_threads); do
+		$cmd &
+		procs+=($!)
+	done
+	echo ${procs[*]}
+
+	# Wait for all tasks to finish
+	# After each task is finished, remove it from the array and reassign the rest of the elements
+	# to the same array, so we can reference the first element.
+	total=${#procs[*]}
+	while [[ $total -ne 0 ]]; do
+		wait ${procs[0]}
+		echo "PID: ${procs[0]} finished"
+		unset 'procs[0]'
+		procs=(${procs[*]})
+		let total--
+	done
+done