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