RobertS

RobertS

Hey, I am trying to set up an elixir escript for a simple script.

I want to pass a result from echo using Linux pipe.

Here is an example:
echo -e '1234' | ./script argument

However in main script function:

  def main(args) do
    IO.inspect(args)
  end

when inspecting args I see only:
["argument"] instead of ["1234", "argument"]

Would appreciate your help or any resources.

Showing Posts 1 to 4

Gelato_Candy

Gelato_Candy

In Elixir, when you pass input through Linux pipe to an escript, the piped input will be available as command-line arguments starting from the second element of the args list. The first element of args will always be the name of the script itself.

Here’s how you can access the piped input in your main script function:

defmodule MyScript do
  def main(args) do
    # The first argument is the name of the script itself
    # The second argument (index 1) will be the piped input
    # The rest of the arguments (index 2 and beyond) will be any other arguments you pass after the pipe
    [piped_input | other_args] = args

    IO.inspect(piped_input)  # This will print the piped input
    IO.inspect(other_args)   # This will print the other arguments after the pipe
  end
end
RobertS

RobertS OP

This doesn’t seem to work for me. With your example, it shows:

"a" in piped_input variable
[] in other_args variable
RobertS

RobertS OP

I found it:
The pipe operator passes the data as stdin so you need to do IO.read(:stdio, :line) in main to read it.

Tuxified

Tuxified

IIRC linux pipes pass info to the next process via STDIN, so I think you need some function from IO module to read it, for example:

defmodule MyScript do
  def main(args) do
    IO.inspect(args, label: "Args")

    Enum.each(IO.stream(:stdio, :line), &IO.write("stdio: #{&1}"))
  end
end

[edit]
You found the anwser while I was looking at Elixir docs :+1:

— All posts loaded —

Where Next? Top

Trending in Questions Top

katta
I having some trouble figuring out if I have set myself too strict of standards for my production server. Currently I can handle 75% of r...
New
brecabral
Documentation While reading the Scoped Routes section, I noticed that the documentation currently refers to a problem without explainin...
New
achenet
Hello, I’m trying to build a basic Phoenix web-app, and I’d like to use Tailwind. However, when I launch mix phx.server, I get an error...
New
kpanic
Hi everyone, I am toying with the idea of building a “match maker” for giving personal help to people that wants to start coding. I sta...
New
asweet-confluent
I recently noticed that Elixir’s Logger defaults its primary log level to :debug when no :logger, :level application configuration is pre...
New
Cxx-mlr
I’m working on a small exercise involving update_in/3, and I came up with this solution: data = %{ name: "Periodic Table", category:...
New
ChrisAmelia
I’ve got trouble wrapping my head around the order in which functions are called in this snippet (from Phoenix’s authentication): toke...
New

Other Trending Topics Top

GenericJam
Edit: 2026 May 15 - This post is archived. Mob is alive!! Main docs: mob v0.7.11 — Documentation A bit of explanation for the slightly c...
New
JesseHerrick
Hey, I’m Jesse and I’m the main contributor behind Dexter, a full-featured, lightning-fast Elixir LSP optimized for large codebases. It s...
New
mudasobwa
I am happy to introduce the very α version of the new programming language compiled to BEAM. Welcome Cure. It has literally three kille...
New
garrison
Hobbes is a low-level distributed database for the Elixir programming language. Hobbes provides a simple, safe, and scalable storage lay...
New
mhanberg
Hi everyone! The first release candidate for the Expert language server project is now available! We’ve published a press release detai...
New
budgie
A little off-topic, but I feel like people here have a good head on their shoulders. I used to be quite good at making software. Was luc...
New

We're in Beta

About us Mission Statement

Options

Thread Display Mode




Thread Preview

Skip Thread Previews