Fungsi dan Script

my_function() {
  echo "Hello from function"
}

my_function

function my_function {
  echo "Hello from function"
}

greet() {
  local name=$1        # $1 = parameter pertama
  local age=$2         # $2 = parameter kedua
  echo "Halo $name, umur $age"
}

greet "Alice" 25
# Output: Halo Alice, umur 25

# Fungsi tidak mengembalikan string langsung
# Return hanya untuk exit code (0-255)

sum() {
  local a=$1
  local b=$2
  echo $((a + b))     # Print hasil, capture dengan command substitution
}

result=$(sum 5 3)
echo "Hasil: $result"

#!/bin/bash

global_var="saya global"

my_func() {
  local local_var="saya lokal"
  global_var="diubah di fungsi"
  echo "$local_var"
}

my_func
echo "$global_var"    # Output: diubah di fungsi
echo "$local_var"      # Output: (kosong, tidak ada)

# Cara modern: $()
current_date=$(date +%Y-%m-%d)
files=$(ls *.txt)

# Cara lama (hindari): backticks
current_date=`date +%Y-%m-%d`

# Here Document (multi-line string)
cat << EOF > config.txt
name=Alice
host=localhost
port=3306
EOF

# Here String (single line)
grep "Alice" <<< "Hello Alice, how are you?"

#!/bin/bash
set -euo pipefail

download_file() {
  local url=$1
  local output=$2

  if ! curl -sf "$url" -o "$output"; then
    echo "Error: Gagal download $url" >&2
    return 1
  fi

  echo "Download berhasil: $output"
}

# Call dengan error handling
if download_file "https://example.com/file.txt" "file.txt"; then
  echo "Proses berhasil"
else
  echo "Proses gagal"
  exit 1
fi

#!/bin/bash

log() {
  local level=$1
  local message=$2
  local timestamp=$(date '+%Y-%m-%d %H:%M:%S')
  echo "[$timestamp] [$level] $message"
}

log "INFO" "Mulai proses"
log "WARN" "Disk hampir penuh"
log "ERROR" "Koneksi gagal"

#!/bin/bash
set -euo pipefail

# Konfigurasi
readonly SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
readonly SCRIPT_NAME="$(basename "$0")"

# Fungsi
usage() {
  cat << EOF
Usage: $SCRIPT_NAME [OPTIONS]

Options:
  -h, --help      Tampilkan bantuan
  -f, --file      Spesifikasi file
  -v, --verbose   Mode verbose

EOF
  exit 0
}

main() {
  # Logic utama
  echo "Running $SCRIPT_NAME from $SCRIPT_DIR"
}

# Parse argument
while [[ $# -gt 0 ]]; do
  case $1 in
    -h|--help) usage ;;
    -f|--file) shift; file=$1 ;;
    -v|--verbose) verbose=1 ;;
    *) echo "Unknown option: $1"; exit 1 ;;
  esac
  shift
done

main "$@"

# Memuat fungsi dan variabel dari file lain
source ./utils.sh
. ./utils.sh        # Cara lama (sama dengan source)

#!/bin/bash

# Cleanup saat script exit
cleanup() {
  echo "Membersihkan temporary files..."
  rm -f /tmp/temp_*.txt
}

trap cleanup EXIT

trap 'echo "Interrupted"; exit 1' INT TERM

# Script utama
sleep 10