DIRENV-FETCHURL(1)

📦
version 2.38.2 · 5 versions
, in arch rolling, nixpkgs unstable

🎀 NAME 🎀

okay bestie, meet direnv-fetchurl(1) from the User Manuals set — it’s literally called Fetch a URL to disk and it does exactly what it says 💅

✨ SYNOPSIS ✨

direnv fetchurl <url> [<integrity-hash>]

💖 DESCRIPTION 💖

This command downloads the URL you give it into a fixed disk location, based on the content of the retrieved file. Iconic behavior, no notes.

It exists so you don’t have to depend on curl or wget, while also promoting a more secure way to fetch data from the Internet. Use this instead of curl <url> | sh 🫶

This command has two modes of operation:

  1. Just pass the URL to discover the integrity hash.
  2. Pass the URL and the integrity hash to get back the on-disk location.

Since the on-disk location is based on the hash, it also acts as a cache. One implication of this design is that URLs must be stable and always return the same content. No sneaky changing files, bestie 😭

Downloaded files are marked as read-only and executable so it can also be used to fetch and execute static binaries. main character energy fr fr 🔥

💅 OPTIONS 💅

  • <url> — A HTTP URL that returns content on HTTP GET requests. 301 and other redirects are followed.
  • <integrity-hash> — When passed, the integrity of the retrieved content will be validated against the given hash. The hash encoding is based on the SRI W3C specification (see https://www.w3.org/TR/SRI/).

🌈 OUTPUT 🌈

direnv fetchurl outputs different content based on the argument.

If the integrity-hash is being passed, it will output the path to the on-disk location, if the retrieval was successful.

If only the url is being passed, it will output the hash as well as some human-readable instruction. If stdout is not a tty, only the hash will be displayed.

🦋 EXAMPLE 🦋

$ ./direnv fetchurl https://releases.nixos.org/nix/nix-2.3.7/install
Found hash: sha256-7Gxl5GzI9juc/U30Igh/pY+p6+gj5Waohfwql3jHIds=

Invoke fetchurl again with the hash as an argument to get the disk location:

  direnv fetchurl "https://releases.nixos.org/nix/nix-2.3.7/install" "sha256-7Gxl5GzI9juc/U30Igh/pY+p6+gj5Waohfwql3jHIds="
  #=> /home/zimbatm/.cache/direnv/cas/sha256-7Gxl5GzI9juc_U30Igh_pY+p6+gj5Waohfwql3jHIds=

🍓 ENVIRONMENT VARIABLES 🍓

  • XDG_CACHE_HOME — This variable is used to select the on-disk location of the fetched URLs as $XDG_CACHE_HOME/direnv/cas. If XDG_CACHE_HOME is unset or empty, defaults to $HOME/.cache.

MIT licence - Copyright (C) 2019 @zimbatm and contributors

💜 SEE ALSO 💜

direnv-stdlib(1)

byeeeee 💖 — this cutie is from direnv, dated 2019, and yes it’s the DIRENV-FETCHURL(1) manual. periodt ✨

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