lix/scripts/nix-prefetch-url.in

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#! /usr/bin/perl -w
use strict;
use IPC::Open2;
my $url = shift @ARGV;
defined $url or die;
print "fetching $url...\n";
my $out = "@prefix@/store/nix-prefetch-url-$$";
system "@wget@ '$url' -O '$out'";
$? == 0 or die "unable to fetch $url";
my $hash=`@bindir@/nix-hash --flat $out`;
$? == 0 or die "unable to hash $out";
chomp $hash;
print "file has hash $hash\n";
my $out2 = "@prefix@/store/nix-prefetch-url-$hash";
rename $out, $out2;
# Create a Fix expression.
my $fixexpr =
"App(IncludeFix(\"fetchurl/fetchurl.fix\"), " .
"[(\"url\", \"$url\"), (\"md5\", \"$hash\")])";
# Instantiate a Nix expression.
print STDERR "running fix...\n";
my $pid = open2(\*READ, \*WRITE, "fix -") or die "cannot run fix";
print WRITE $fixexpr;
close WRITE;
my $id = <READ>;
chomp $id;
waitpid $pid, 0;
$? == 0 or die "fix failed";
# Run Nix.
print STDERR "running nix...\n";
system "nix --install $id > /dev/null";
$? == 0 or die "`nix --install' failed";
unlink $out2;