diff options
Diffstat (limited to 'doc/manual/command-ref/nix-env.xml')
| -rw-r--r-- | doc/manual/command-ref/nix-env.xml | 53 |
1 files changed, 39 insertions, 14 deletions
diff --git a/doc/manual/command-ref/nix-env.xml b/doc/manual/command-ref/nix-env.xml index 56c466268..d257a5e49 100644 --- a/doc/manual/command-ref/nix-env.xml +++ b/doc/manual/command-ref/nix-env.xml @@ -221,31 +221,53 @@ also <xref linkend="sec-common-options" />.</phrase></para> <varlistentry><term><filename>~/.nix-defexpr</filename></term> - <listitem><para>A directory that contains the default Nix + <listitem><para>The source for the default Nix expressions used by the <option>--install</option>, <option>--upgrade</option>, and <option>--query - --available</option> operations to obtain derivations. The + --available</option> operations to obtain derivations. The <option>--file</option> option may be used to override this default.</para> - <para>The Nix expressions in this directory are combined into a - single set, with each file as an attribute that has the name of - the file. Thus, if <filename>~/.nix-defexpr</filename> contains - two files, <filename>foo</filename> and <filename>bar</filename>, + <para>If <filename>~/.nix-defexpr</filename> is a file, + it is loaded as a Nix expression. If the expression + is a set, it is used as the default Nix expression. + If the expression is a function, an empty set is passed + as argument and the return value is used as + the default Nix expression.</para> + + <para>If <filename>~/.nix-defexpr</filename> is a directory + containing a <filename>default.nix</filename> file, that file + is loaded as in the above paragraph.</para> + + <para>If <filename>~/.nix-defexpr</filename> is a directory without + a <filename>default.nix</filename> file, then its contents + (both files and subdirectories) are loaded as Nix expressions. + The expressions are combined into a single set, each expression + under an attribute with the same name as the original file + or subdirectory. + </para> + + <para>For example, if <filename>~/.nix-defexpr</filename> contains + two files, <filename>foo.nix</filename> and <filename>bar.nix</filename>, then the default Nix expression will essentially be <programlisting> { - foo = import ~/.nix-defexpr/foo; - bar = import ~/.nix-defexpr/bar; + foo = import ~/.nix-defexpr/foo.nix; + bar = import ~/.nix-defexpr/bar.nix; }</programlisting> </para> + <para>The file <filename>manifest.nix</filename> is always ignored. + Subdirectories without a <filename>default.nix</filename> file + are traversed recursively in search of more Nix expressions, + but the names of these intermediate directories are not + added to the attribute paths of the default Nix expression.</para> + <para>The command <command>nix-channel</command> places symlinks to the downloaded Nix expressions from each subscribed channel in this directory.</para> - </listitem> </varlistentry> @@ -637,7 +659,7 @@ upgrading `mozilla-1.2' to `mozilla-1.4'</screen> <literal>gcc-3.3.1</literal> are split into two parts: the package name (<literal>gcc</literal>), and the version (<literal>3.3.1</literal>). The version part starts after the first -dash not following by a letter. <varname>x</varname> is considered an +dash not followed by a letter. <varname>x</varname> is considered an upgrade of <varname>y</varname> if their package names match, and the version of <varname>y</varname> is higher that that of <varname>x</varname>.</para> @@ -1348,10 +1370,13 @@ profile. The generations can be a list of generation numbers, the special value <literal>old</literal> to delete all non-current generations, a value such as <literal>30d</literal> to delete all generations older than the specified number of days (except for the -generation that was active at that point in time), or a value such as. -<literal>+5</literal> to only keep the specified items older than the -current generation. Periodically deleting old generations is important -to make garbage collection effective.</para> +generation that was active at that point in time), or a value such as +<literal>+5</literal> to keep the last <literal>5</literal> generations +ignoring any newer than current, e.g., if <literal>30</literal> is the current +generation <literal>+5</literal> will delete generation <literal>25</literal> +and all older generations. +Periodically deleting old generations is important to make garbage collection +effective.</para> </refsection> |