Combines 'cd' and 'ls' commands to change directories and immediately list their contents to speed up file system navigation

cdl.sh

#!/bin/bash

# Author: Nikita Neverov (BMTLab)
# Version: 1.0.1
#
# cdl: Change the current working directory and list its contents (cd ... && ls -a).
# This function changes the current working directory to the specified directory
# or to $HOME if no directory is specified, and then lists the contents of the directory.
#
function cdl() {
  local -r args=$1
  local help_message

  # Multi-line usage message
  read -r -d '' help_message <<'EOF'
Usage: cdl [<directory>]
Change the current working directory to <directory> (or $HOME if not specified) and list its contents.
EOF

  # Display help message if -h or --help is passed as an argument.
  if [[ $args == '-h' ]] || [[ $args == '--help' ]]; then
    echo "$help_message"
    return 0
  fi

  # Set default argument as HOME if not provided
  local -r dir="${1:-$HOME}"
  local -r dir_not_exist_error='Error: Directory does not exist or cannot be accessed: '

  # Change directory and list contents if successful
  if cd "$dir" >/dev/null 2>&1; then
    ls -a --color=auto
  else
    # Display error message if cd command fails
    local -ir cd_error_code=$?
    echo "${dir_not_exist_error}'$dir'" >&2
    return $cd_error_code
  fi
}