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57 lines
1.6 KiB
Text
57 lines
1.6 KiB
Text
= Hello, flake!
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// TODO Need an intro explaining what flakes are. Move the "why flakes" section here.
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Before learning to write Nix flakes, let's learn how to use them. I've
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created a simple example of a flake in this git
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https://codeberg.org/mhwombat/hello-flake[repository]. To run this
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flake, you don't need to install anything; simply run the command below.
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The first time you use a flake, Nix has to fetch and build it, which
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may take time. Subsequent invocations should be instantaneous.
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....
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$ nix run "git+https://codeberg.org/mhwombat/hello-flake"
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....
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That's a lot to type every time we want to use this package. Instead, we
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can enter a shell with the package available to us, using the
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`nix shell` command.
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....
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$ nix shell "git+https://codeberg.org/mhwombat/hello-flake"
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....
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In this shell, the command is on our `$PATH`, so we can execute the
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command by name.
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....
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$ hello-flake
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....
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Nix didn't _install_ the package; it merely built and placed it in a
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directory called the "`Nix store`". Thus we can have multiple versions
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of a package without worrying about conflicts. We can find out the
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location of the executable, if we're curious.
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....
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$ which hello-flake
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....
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Once we exit that shell, the `hello-flake` command is no longer
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directly available.
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....
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$# echo '$ exit'
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$# echo '$ hello-flake'
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sh: line 3: hello-flake: command not found
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....
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However, we can still run the command using the store path we found
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earlier. That's not particularly convenient, but it does demonstrate
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that the package remains in the store for future use.
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....
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$# executable=$(which hello-flake)
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$# echo '$ '${executable}
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$# ${executable}
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....
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