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Diffstat (limited to 'doc/manual/nix-store.xml')
| -rw-r--r-- | doc/manual/nix-store.xml | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/doc/manual/nix-store.xml b/doc/manual/nix-store.xml index a168be024dec..da3eae2ec402 100644 --- a/doc/manual/nix-store.xml +++ b/doc/manual/nix-store.xml @@ -779,4 +779,178 @@ archive is read from standard input.</para> </refsection> +<!--######################################################################--> + +<refsection xml:id='refsec-nix-store-export'><title>Operation <option>--export</option></title> + +<refsection> + <title>Synopsis</title> + <cmdsynopsis> + <command>nix-store</command> + <arg choice='plain'><option>--export</option></arg> + <arg choice='plain' rep='repeat'><replaceable>paths</replaceable></arg> + </cmdsynopsis> +</refsection> + +<refsection><title>Description</title> + +<para>The operation <option>--export</option> writes a serialisation +of the specified store paths to standard output in a format that can +be imported into another Nix store with <command +linkend="refsec-nix-store-import">nix-store --import</command>. This +is like <command linkend="refsec-nix-store-dump">nix-store +--dump</command>, except that the NAR archive produced by that command +doesn’t contain the necessary meta-information to allow it to be +imported into another Nix store (namely, the set of references of the +path).</para> + +<para>This command does not produce a <emphasis>closure</emphasis> of +the specified paths, so if a store path references other store paths +that are missing in the target Nix store, the import will fail. To +copy a whole closure, do something like + +<screen> +$ nix-store --export $(nix-store -qR <replaceable>paths</replaceable>) > out</screen> + +</para> + +<para>For an example of how <option>--export</option> and +<option>--import</option> can be used, see the source of the <command +linkend="sec-nix-copy-closure">nix-copy-closure</command> +command.</para> + +</refsection> + + +</refsection> + + +<!--######################################################################--> + +<refsection xml:id='refsec-nix-store-import'><title>Operation <option>--import</option></title> + +<refsection> + <title>Synopsis</title> + <cmdsynopsis> + <command>nix-store</command> + <arg choice='plain'><option>--import</option></arg> + </cmdsynopsis> +</refsection> + +<refsection><title>Description</title> + +<para>The operation <option>--export</option> reads a serialisation of +a set of store paths produced by <command +linkend="refsec-nix-store-export">nix-store --import</command> from +standard input and adds those store paths to the Nix store. Paths +that already exist in the Nix store are ignored. If a path refers to +another path that doesn’t exist in the Nix store, the import +fails.</para> + +</refsection> + + +</refsection> + + +<!--######################################################################--> + +<refsection><title>Operation <option>--optimise</option></title> + +<refsection> + <title>Synopsis</title> + <cmdsynopsis> + <command>nix-store</command> + <arg choice='plain'><option>--optimise</option></arg> + </cmdsynopsis> +</refsection> + +<refsection><title>Description</title> + +<para>The operation <option>--optimise</option> reduces Nix store disk +space usage by finding identical files in the store and hard-linking +them to each other. It typically reduces the size of the store by +something like 25-35%. Only regular files and symlinks are +hard-linked in this manner. Files are considered identical when they +have the same NAR archive serialisation: that is, regular files must +have the same contents and permission (executable or non-executable), +and symlinks must have the same contents.</para> + +<para>After completion, or when the command is interrupted, a report +on the achieved savings is printed on standard error.</para> + +<para>Use <option>-vv</option> or <option>-vvv</option> to get some +progress indication.</para> + +</refsection> + +<refsection><title>Example</title> + +<screen> +$ nix-store --optimise +hashing files in `/nix/store/qhqx7l2f1kmwihc9bnxs7rc159hsxnf3-gcc-4.1.1' +<replaceable>...</replaceable> +541838819 bytes (516.74 MiB) freed by hard-linking 54143 files; +there are 114486 files with equal contents out of 215894 files in total +</screen> + +</refsection> + + +</refsection> + + +<!--######################################################################--> + +<refsection><title>Operation <option>--read-log</option></title> + +<refsection> + <title>Synopsis</title> + <cmdsynopsis> + <command>nix-store</command> + <group choice='req'> + <arg choice='plain'><option>--read-log</option></arg> + <arg choice='plain'><option>-l</option></arg> + </group> + <arg choice='plain' rep='repeat'><replaceable>paths</replaceable></arg> + </cmdsynopsis> +</refsection> + +<refsection><title>Description</title> + +<para>The operation <option>--read-log</option> prints the build log +of the specified store paths on standard output. The build log is +whatever the builder of a derivation wrote to standard output and +standard error. If a store path is not a derivation, the deriver of +the store path is used.</para> + +<para>Build logs are kept in +<filename>/nix/var/log/nix/drvs</filename>. However, there is no +guarantee that a build log is available for any particular store +path. For instance, if the path was downloaded as a pre-built binary +through a substitute, then the log is unavailable.</para> + +</refsection> + +<refsection><title>Example</title> + +<screen> +$ nix-store -l $(which ktorrent) +building /nix/store/dhc73pvzpnzxhdgpimsd9sw39di66ph1-ktorrent-2.2.1 +unpacking sources +unpacking source archive /nix/store/p8n1jpqs27mgkjw07pb5269717nzf5f8-ktorrent-2.2.1.tar.gz +ktorrent-2.2.1/ +ktorrent-2.2.1/NEWS +<replaceable>...</replaceable> +</screen> + +</refsection> + + +</refsection> + + +<!-- TODO: export, import operations --> + + </refentry> |