nix-super/src/nix/path-info.md
John Ericson cc46ea1630 Make nix path-info --json return an object not array
Before it returned a list of JSON objects with store object information,
including the path in each object. Now, it maps the paths to JSON
objects with the metadata sans path.

This matches how `nix derivation show` works.

Quite hillariously, none of our existing functional tests caught this
change to `path-info --json` though they did use it. So just new
functional tests need to be added.
2023-11-06 11:06:31 -05:00

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2.9 KiB
Markdown

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# Examples
* Print the store path produced by `nixpkgs#hello`:
```console
# nix path-info nixpkgs#hello
/nix/store/v5sv61sszx301i0x6xysaqzla09nksnd-hello-2.10
```
* Show the closure sizes of every path in the current NixOS system
closure, sorted by size:
```console
# nix path-info --recursive --closure-size /run/current-system | sort -nk2
/nix/store/hl5xwp9kdrd1zkm0idm3kkby9q66z404-empty 96
/nix/store/27324qvqhnxj3rncazmxc4mwy79kz8ha-nameservers 112
/nix/store/539jkw9a8dyry7clcv60gk6na816j7y8-etc 5783255504
/nix/store/zqamz3cz4dbzfihki2mk7a63mbkxz9xq-nixos-system-machine-20.09.20201112.3090c65 5887562256
```
* Show a package's closure size and all its dependencies with human
readable sizes:
```console
# nix path-info --recursive --size --closure-size --human-readable nixpkgs#rustc
/nix/store/01rrgsg5zk3cds0xgdsq40zpk6g51dz9-ncurses-6.2-dev 386.7K 69.1M
/nix/store/0q783wnvixpqz6dxjp16nw296avgczam-libpfm-4.11.0 5.9M 37.4M
```
* Check the existence of a path in a binary cache:
```console
# nix path-info --recursive /nix/store/blzxgyvrk32ki6xga10phr4sby2xf25q-geeqie-1.5.1 --store https://cache.nixos.org/
path '/nix/store/blzxgyvrk32ki6xga10phr4sby2xf25q-geeqie-1.5.1' is not valid
```
* Print the 10 most recently added paths (using --json and the jq(1)
command):
```console
# nix path-info --json --all | jq -r 'to_entries | sort_by(.value.registrationTime) | .[-11:-1][] | .key'
```
* Show the size of the entire Nix store:
```console
# nix path-info --json --all | jq 'map(.narSize) | add'
49812020936
```
* Show every path whose closure is bigger than 1 GB, sorted by closure
size:
```console
# nix path-info --json --all --closure-size \
| jq 'map_values(.closureSize | select(. < 1e9)) | to_entries | sort_by(.value)'
[
…,
{
.key = "/nix/store/zqamz3cz4dbzfihki2mk7a63mbkxz9xq-nixos-system-machine-20.09.20201112.3090c65",
.value = 5887562256,
}
]
```
* Print the path of the [store derivation] produced by `nixpkgs#hello`:
[store derivation]: ../../glossary.md#gloss-store-derivation
```console
# nix path-info --derivation nixpkgs#hello
/nix/store/s6rn4jz1sin56rf4qj5b5v8jxjm32hlk-hello-2.10.drv
```
# Description
This command shows information about the store paths produced by
[*installables*](./nix.md#installables), or about all paths in the store if you pass `--all`.
By default, this command only prints the store paths. You can get
additional information by passing flags such as `--closure-size`,
`--size`, `--sigs` or `--json`.
> **Warning**
>
> Note that `nix path-info` does not build or substitute the
> *installables* you specify. Thus, if the corresponding store paths
> don't already exist, this command will fail. You can use `nix build`
> to ensure that they exist.
)""