40 lines
1.6 KiB
Markdown
40 lines
1.6 KiB
Markdown
# Hints
|
|
|
|
## 1. General
|
|
|
|
- Read about files in the official [Getting Started guide][getting-started-file].
|
|
- Read about files on [joyofelixir.com][joy-of-elixir-file].
|
|
- Take a look at the [documentation of the `File` module][file].
|
|
|
|
## 1. Read email addresses from a file
|
|
|
|
- There is a [built-in function][file-read] for reading the contents of a file all at once.
|
|
|
|
## 2. Open a log file for writing
|
|
|
|
- There is a [built-in function][file-open] for opening a file.
|
|
- The second argument of that function is a list of modes which allows specifying that the file should be opened for writing.
|
|
|
|
## 3. Log a sent email
|
|
|
|
- Functions for reading and writing to a file opened with [`File.open!/1`][file-open] can be found in the [`IO`][io] module.
|
|
- There is a [built-in function][io-puts] for writing a string to a file, followed by a newline.
|
|
|
|
## 4. Close the log file
|
|
|
|
- There is a [built-in function][file-close] for closing a file.
|
|
|
|
## 5. Send the newsletter
|
|
|
|
- All the necessary operations on files were already implemented in the previous steps.
|
|
- Before writing to a file, the file must be opened.
|
|
- After all write operations to a file finished, the file should be closed.
|
|
|
|
[getting-started-file]: https://elixir-lang.org/getting-started/io-and-the-file-system.html#the-file-module
|
|
[joy-of-elixir-file]: https://joyofelixir.com/11-files/
|
|
[file]: https://hexdocs.pm/elixir/File.html
|
|
[file-read]: https://hexdocs.pm/elixir/File.html#read!/1
|
|
[file-open]: https://hexdocs.pm/elixir/File.html#open!/1
|
|
[file-close]: https://hexdocs.pm/elixir/File.html#close/1
|
|
[io]: https://hexdocs.pm/elixir/IO.html
|
|
[io-puts]: https://hexdocs.pm/elixir/IO.html#puts/2 |