Traverse the directory tree upwards to the marked directory

marked_dir_finder.sh

#!/usr/bin/env sh
# Traverse the directory tree upwards to the marked directory.
MARKER_DIR=".git" # Arbitrary directory like '.git', '.env', etc.

display_help() {
  cat <<EOF
Usage: $(basename "$0") [OPTIONS]

Options:
  --help    Display this help message and exit.

Description:
This script is designed to be executed using the "source" command:
  source $(basename "$0")

Purpose:
The script navigates upwards through the directory hierarchy from the current 
working directory and stops when it finds a specific marker directory 
(default: ".git"). Once the marker directory is found, the script changes the 
current working directory to its parent directory, effectively placing the user 
in the directory containing the marker.

Key Features:
- Traverse the directory tree upwards, checking each level for the marker directory.
- Automatically changes the shell's working directory to the parent of the marker directory.
- The marker directory can be customized by altering the MARKER_DIR variable 
  (default is ".git").

Examples:
1. To find the nearest ".git" directory and navigate to its parent:
   source $(basename "$0")

2. To display this help message:
   source $(basename "$0") --help
EOF
}

go_up_to_marker() {
  current_dir=$PWD
  while [ "${current_dir}" != "/" ]; do
    marker_to_be_checked="${current_dir}/${MARKER_DIR}"
    echo "Checking directory: ${current_dir}"
    if [ -d "${marker_to_be_checked}" ]; then
      printf "\033[93mDirectory found   : %s\033[0m\n" "${marker_to_be_checked}"
      cd "${current_dir}" || {
        echo "Failed to cd into ${current_dir}"
        exit 1
      }
      printf "\033[93m    You are now in: %s\033[0m\n" "${current_dir}"
      return 0
    fi
    current_dir=$(dirname "$current_dir")
  done

  printf "\033[93m%s not found up to root.\033[0m\n" "${MARKER_DIR}"
  return 1
}

main() {
  [ "$1" = "--help" ] || [ -L "$0" ] && display_help && exit 0
  go_up_to_marker
}

main "$@"