Reading a text file

Elixir:
Reading a text file

How to:

Here’s how to read the entire contents of a text file named example.txt:

File.read("example.txt")

Sample output if example.txt contains “Hello, Elixir!”:

{:ok, "Hello, Elixir!"}

To read the file line by line:

File.stream!("example.txt")
|> Enum.each(fn line -> IO.puts(line) end)

This will print each line of example.txt to the console.

Deep Dive

In Elixir, File.read/1 and File.stream!/1 are typical ways to read text files. Historically, file reading in programming originates from the need to store and retrieve data. In early computing, this was done using punch cards or magnetic tapes. Today, we use various storage devices like SSDs, HDDs, and more.

An alternative to File.read/1 is File.read!/1, which raises an error if something goes wrong instead of returning a tuple. Similarly, File.stream!/1 differs from File.stream/1 by raising an error on failure rather than returning an error tuple.

The implementation under the hood deals with binary data. Text is converted into binaries by Elixir, which handles the underlying bytes and encoding.

Elixir:Reading a text file

How to:

Deep Dive

See Also:

Elixir:
Reading a text file