scan-link

Scan given website recursively and report 404 links

Features

• Start scanning from a specified entry URL
• Follow links within specified origins
• Report links that lead to 404 pages
• Export 404 error report as a CSV file

Remark

The links and page status code are stored in the db.sqlite3 file of the current working directory. You may run mkdir and cd to a specific directory to avoid storing it in the home directory.

Installation (optional)

You can install scan-link for version control, or execute it via npx without installation.

To install scan-link, use npm:

npm install scan-link

You may install it as dev dependency or global dependency based on your preference.

Usage

You can use scan-link from the command line via npx. The configuration can be provided via environment variables or interactively during execution.

Usage with dev/global installation:

npx scan-link [entryUrl]

Usage without installation:

npx -y scan-link [entryUrl]

The entryUrl can be specified in argument, loaded from environment variable, or answered in the interactive prompt.

Environment Variables

• SITE_URL: The entry URL for the scan
• ORIGINS: A comma-separated list of origins to limit the scan
• REPORT_404_CSV_FILE: Path of the CSV file where the 404 error report will be saved

Example content of .env file:

SITE_DIR=https://example.com
ORIGINS=https://example.com,https://sub.example.com
REPORT_404_CSV_FILE=report.csv

Interactive Usage

If environment variables are not set, scan-link will prompt you for the necessary information.

npx scan-link

You will be prompted to setup above variables.

Example Interactive Session

$ npx -y scan-link
entryUrl: http://localhost:8200/

Please specified the origins of links to follow.
Multiple origins can be delimited by comma (",").
origins (default: "http://localhost:8200"):
origins: [ 'http://localhost:8200' ]

path of CSV file to be saved (default "404.csv"): report.csv
scanned: 12 | pending: 85 | scanning: http://localhost:8200/about
...
scanned: 119 pages
{
  '404 link count': 1447,
  'total link count': 5036,
  'page count with 404 link': 11,
  'total page count': 119
}
exported 404 pages to file: report.csv

API

For advanced usage, you can import and use the scanAndFollow() functions programmatically.

export function scanAndFollow(options: {
  /** @example 'http://localhost:8200/' */
  entryUrl: string

  /** @default same as entryUrl */
  origins?: string[]

  /** @description report stats on 404 pages and links */
  report_404_stats?: boolean

  /** @description specified filename to report 404 links. Skip reporting if not specified. */
  export_404_csv_file?: string

  /**
   * @description auto close browser after all scanning
   * @default true
   */
  close_browser?: boolean
}): Promise<void>

/** @description called by `scanAndFollow()` if `options.report_404_stats` is true */
export function get404Report(options: { origin: string }): {
  '404 link count': number
  'total link count': number
  'page count with 404 link': number
  'total page count': number
}

/** @description called by `scanAndFollow()` if `options.export_404_csv_file` is specified */
export function export404Pages(options: {
  csv_file: string
  origin: string
}): void

/** @description close the lazy loaded browser instance if it's launched */
export function closeBrowser(): Promise<void>

License

This project is licensed with BSD-2-Clause

This is free, libre, and open-source software. It comes down to four essential freedoms [ref]:

• The freedom to run the program as you wish, for any purpose
• The freedom to study how the program works, and change it so it does your computing as you wish
• The freedom to redistribute copies so you can help others
• The freedom to distribute copies of your modified versions to others