#!/bin/bash#!/usr/bin/env bash

chmod+x script.sh./script.sh

set-euo pipefail

if [[ -f"file.txt" ]]; thenecho"exists"; fi

if [[ "$count"-gt0 ]]; thenecho"positive"; elif [[ "$count"-eq0 ]]; thenecho"zero"; elseecho"negative"; fiif [[ "$input"=~ ^[0-9]+$ ]]; thenecho"is a number"; fi

case "$1"instart) echo"Starting";; stop) echo"Stopping";; *) echo"Usage: $0 {start|stop}";; esac

for file in *.txt; doecho"$file"; donefor i in {1..10}; doecho"$i"; donefor ((i=0; i<10; i++)); doecho"$i"; done

whileIFS= read -r line; doecho"$line"; done < file.txt

until [[ -f"ready.flag" ]]; dosleep1; done

greet() { local name="$1"; echo"Hello, $name"; }greet "World"

get_date() { date +%Y-%m-%d; }today=$(get_date)

for item in"${arr[@]}"; doecho"$item"; done

declare -A mapmap[key]="value"echo"${map[key]}"

echo"scale=2; 10 / 3" | bc

read -p "Enter name: " nameread -s -p "Password: " passread -r -a items <<< "a b c"

printf "Name: %s, Age: %d\n""$name""$age"

bash -x script.sh

set -xset +x

shellcheck script.sh