Writing bash scripts with Nix

Variables, such as username, can be injected.

shellcheck is run automatically with pkgs.writeShellApplication.

Packages defined in runtimeInputs will be automatically injected.

https://github.com/opdavies/dotfiles.nix/blob/a1c356a1f576f041301a5c41d6ba7d0f098d0edb/lib/shared/scripts/export-video-list.nix

{ pkgs, username, ... }:

{
name = "export-video-list";

runtimeInputs = with pkgs; [
jq
tree
udisks
];

text = ''
device_name="/dev/sda2"
device_label="UNTITLED"

source_path="/run/media/${username}/$device_label"

# If the source path doesn't exist, try mounting the device.
if [[ ! -d "$source_path" ]]; then
${pkgs.udisks}/bin/udisksctl mount -b "$device_name"
fi

# Exit early if the source path still doesn't exist.
if [[ ! -d "$source_path" ]]; then
echo "Error: $source_path not found."
exit 1
fi

output_file="$HOME/Documents/videos.json"

${pkgs.tree}/bin/tree -J "$source_path/Videos" | ${pkgs.jq}/bin/jq . > "$output_file"
${pkgs.jq}/bin/jq . < "$output_file"
'';
}