92e832348d
* nix-pull now requires the full url to the manifest, i.e., `/MANIFEST/' is no longer automatically appended. * nix-prefetch-url works again.
54 lines
1.8 KiB
XML
54 lines
1.8 KiB
XML
<refentry>
|
|
<refnamediv>
|
|
<refname>nix-prefetch-url</refname>
|
|
<refpurpose>copy a file from a URL into the store and print its MD5 hash</refpurpose>
|
|
</refnamediv>
|
|
|
|
<refsynopsisdiv>
|
|
<cmdsynopsis>
|
|
<command>nix-prefetch-url</command>
|
|
<arg choice='plain'><replaceable>url</replaceable></arg>
|
|
</cmdsynopsis>
|
|
</refsynopsisdiv>
|
|
|
|
<refsection>
|
|
<title>Description</title>
|
|
|
|
<para>
|
|
The command <command>nix-prefetch-url</command> downloads the
|
|
file referenced by the URL <replaceable>url</replaceable>,
|
|
prints its MD5 cryptographic hash code, and copies it into the
|
|
Nix store. The file name in the store is
|
|
<filename><replaceable>hash</replaceable>-<replaceable>basename</replaceable></filename>,
|
|
where <replaceable>basename</replaceable> is everything
|
|
following the final slash in <replaceable>url</replaceable>.
|
|
</para>
|
|
|
|
<para>
|
|
This command is just a convenience to Nix expression writers.
|
|
Often a Nix expressions fetch some source distribution from the
|
|
network using the <literal>fetchurl</literal> expression
|
|
contained in <literal>nixpkgs</literal>. However,
|
|
<literal>fetchurl</literal> requires an MD5 hash. If you don't
|
|
know the hash, you would have to download the file first, and
|
|
then <literal>fetchurl</literal> would download it again when
|
|
you build your Nix expression. Since
|
|
<literal>fetchurl</literal> uses the same name for the
|
|
downloaded file as <command>nix-prefetch-url</command>, the
|
|
redundant download can be avoided.
|
|
</para>
|
|
|
|
</refsection>
|
|
|
|
<refsection>
|
|
<title>Examples</title>
|
|
|
|
<screen>
|
|
$ nix-prefetch-url ftp://ftp.nluug.nl/pub/gnu/make/make-3.80.tar.bz2
|
|
...
|
|
file has hash 0bbd1df101bc0294d440471e50feca71
|
|
...</screen>
|
|
|
|
</refsection>
|
|
|
|
</refentry>
|