nix-super/doc/manual/source/command-ref/nix-store/query.md

Name

nix-store --query - display information about store paths

Synopsis

nix-store {--query | -q} {--outputs | --requisites | -R | --references | --referrers | --referrers-closure | --deriver | -d | --valid-derivers | --graph | --tree | --binding name | -b name | --hash | --size | --roots} [--use-output] [-u] [--force-realise] [-f] paths…

Description

The operation --query displays various bits of information about the store paths . The queries are described below. At most one query can be specified. The default query is --outputs.

The paths paths may also be symlinks from outside of the Nix store, to the Nix store. In that case, the query is applied to the target of the symlink.

Common query options

• --use-output / -u

  For each argument to the query that is a store derivation, apply the query to the output path of the derivation instead.

• --force-realise / -f

  Realise each argument to the query first (see nix-store --realise).

Queries

• --outputs

  Prints out the output paths of the store derivations paths. These are the paths that will be produced when the derivation is built.

• --requisites / -R

  Prints out the closure of the store path paths.

  This query has one option:

  • --include-outputs Also include the existing output paths of store derivations, and their closures.

  This query can be used to implement various kinds of deployment. A source deployment is obtained by distributing the closure of a store derivation. A binary deployment is obtained by distributing the closure of an output path. A cache deployment (combined source/binary deployment, including binaries of build-time-only dependencies) is obtained by distributing the closure of a store derivation and specifying the option --include-outputs.

• --references

  Prints the set of references of the store paths paths, that is, their immediate dependencies. (For all dependencies, use --requisites.)

• --referrers

  Prints the set of referrers of the store paths paths, that is, the store paths currently existing in the Nix store that refer to one of paths. Note that contrary to the references, the set of referrers is not constant; it can change as store paths are added or removed.

• --referrers-closure

  Prints the closure of the set of store paths paths under the referrers relation; that is, all store paths that directly or indirectly refer to one of paths. These are all the path currently in the Nix store that are dependent on paths.

• --deriver / -d

  Prints the deriver that was used to build the store paths paths. If the path has no deriver (e.g., if it is a source file), or if the deriver is not known (e.g., in the case of a binary-only deployment), the string unknown-deriver is printed. The returned deriver is not guaranteed to exist in the local store, for example when paths were substituted from a binary cache. Use --valid-derivers instead to obtain valid paths only.

• --valid-derivers

  Prints a set of derivation files (.drv) which are supposed produce said paths when realized. Might print nothing, for example for source paths or paths substituted from a binary cache.

• --graph

  Prints the references graph of the store paths paths in the format of the dot tool of AT&T's Graphviz package. This can be used to visualise dependency graphs. To obtain a build-time dependency graph, apply this to a store derivation. To obtain a runtime dependency graph, apply it to an output path.

• --tree

  Prints the references graph of the store paths paths as a nested ASCII tree. References are ordered by descending closure size; this tends to flatten the tree, making it more readable. The query only recurses into a store path when it is first encountered; this prevents a blowup of the tree representation of the graph.

• --graphml

  Prints the references graph of the store paths paths in the GraphML file format. This can be used to visualise dependency graphs. To obtain a build-time dependency graph, apply this to a store derivation. To obtain a runtime dependency graph, apply it to an output path.

• --binding name / -b name

  Prints the value of the attribute name (i.e., environment variable) of the store derivations paths. It is an error for a derivation to not have the specified attribute.

• --hash

  Prints the SHA-256 hash of the contents of the store paths paths (that is, the hash of the output of nix-store --dump on the given paths). Since the hash is stored in the Nix database, this is a fast operation.

• --size

  Prints the size in bytes of the contents of the store paths paths — to be precise, the size of the output of nix-store --dump on the given paths. Note that the actual disk space required by the store paths may be higher, especially on filesystems with large cluster sizes.

• --roots

  Prints the garbage collector roots that point, directly or indirectly, at the store paths paths.

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Examples

Print the closure (runtime dependencies) of the svn program in the current user environment:

$ nix-store --query --requisites $(which svn)
/nix/store/5mbglq5ldqld8sj57273aljwkfvj22mc-subversion-1.1.4
/nix/store/9lz9yc6zgmc0vlqmn2ipcpkjlmbi51vv-glibc-2.3.4
...

Print the build-time dependencies of svn:

$ nix-store --query --requisites $(nix-store --query --deriver $(which svn))
/nix/store/02iizgn86m42q905rddvg4ja975bk2i4-grep-2.5.1.tar.bz2.drv
/nix/store/07a2bzxmzwz5hp58nf03pahrv2ygwgs3-gcc-wrapper.sh
/nix/store/0ma7c9wsbaxahwwl04gbw3fcd806ski4-glibc-2.3.4.drv
... lots of other paths ...

The difference with the previous example is that we ask the closure of the derivation (-qd), not the closure of the output path that contains svn.

Show the build-time dependencies as a tree:

$ nix-store --query --tree $(nix-store --query --deriver $(which svn))
/nix/store/7i5082kfb6yjbqdbiwdhhza0am2xvh6c-subversion-1.1.4.drv
+---/nix/store/d8afh10z72n8l1cr5w42366abiblgn54-builder.sh
+---/nix/store/fmzxmpjx2lh849ph0l36snfj9zdibw67-bash-3.0.drv
|   +---/nix/store/570hmhmx3v57605cqg9yfvvyh0nnb8k8-bash
|   +---/nix/store/p3srsbd8dx44v2pg6nbnszab5mcwx03v-builder.sh
...

Show all paths that depend on the same OpenSSL library as svn:

$ nix-store --query --referrers $(nix-store --query --binding openssl $(nix-store --query --deriver $(which svn)))
/nix/store/23ny9l9wixx21632y2wi4p585qhva1q8-sylpheed-1.0.0
/nix/store/5mbglq5ldqld8sj57273aljwkfvj22mc-subversion-1.1.4
/nix/store/dpmvp969yhdqs7lm2r1a3gng7pyq6vy4-subversion-1.1.3
/nix/store/l51240xqsgg8a7yrbqdx1rfzyv6l26fx-lynx-2.8.5

Show all paths that directly or indirectly depend on the Glibc (C library) used by svn:

$ nix-store --query --referrers-closure $(ldd $(which svn) | grep /libc.so | awk '{print $3}')
/nix/store/034a6h4vpz9kds5r6kzb9lhh81mscw43-libgnomeprintui-2.8.2
/nix/store/15l3yi0d45prm7a82pcrknxdh6nzmxza-gawk-3.1.4
...

Note that ldd is a command that prints out the dynamic libraries used by an ELF executable.

Make a picture of the runtime dependency graph of the current user environment:

$ nix-store --query --graph ~/.nix-profile | dot -Tps > graph.ps
$ gv graph.ps

Show every garbage collector root that points to a store path that depends on svn:

$ nix-store --query --roots $(which svn)
/nix/var/nix/profiles/default-81-link
/nix/var/nix/profiles/default-82-link
/home/eelco/.local/state/nix/profiles/profile-97-link