#!/bin/bash # try to use sleep if available if [ -x "$(command -v sleep)" ]; then sleep "$1" exit 0 fi # try to use ping if available if [ -x "$(command -v ping)" ]; then ping -c $(( $1 + 1 )) 127.0.0.1 > /dev/null exit 0 fi # try to use read -t from stdin/stdout/stderr if we are in bash if [ -n "$BASH_VERSION" ]; then if command -v read >/dev/null 2>&1; then if [ -t 0 ]; then read -t "$1" -u 0 || :; exit 0 fi if [ -t 1 ]; then read -t "$1" -u 1 || :; exit 0 fi if [ -t 2 ]; then read -t "$1" -u 2 || :; exit 0 fi fi fi # fallback to a busy wait SECONDS=0 while [[ $SECONDS -lt $1 ]]; do : done