* Documented a bunch of nix-store commands.

This commit is contained in:
Eelco Dolstra 2007-12-31 01:52:57 +00:00
parent 454f571f87
commit 6bdecfacbb

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@ -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
doesnt 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 doesnt 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>