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#! @perl@ -w @perlFlags@
use strict;
use File::Basename;
use File::Path qw(mkpath);
use Nix::Config;
my $manifestDir = $Nix::Config::manifestDir;
# Turn on caching in nix-prefetch-url.
my $channelCache = "$Nix::Config::stateDir/channel-cache";
mkdir $channelCache, 0755 unless -e $channelCache;
$ENV{'NIX_DOWNLOAD_CACHE'} = $channelCache if -W $channelCache;
# Figure out the name of the `.nix-channels' file to use.
my $home = $ENV{"HOME"} or die '$HOME not set\n';
my $channelsList = "$home/.nix-channels";
my $nixDefExpr = "$home/.nix-defexpr";
# Figure out the name of the channels profile.
my $userName = getpwuid($<) or die "cannot figure out user name";
my $profile = "$Nix::Config::stateDir/profiles/per-user/$userName/channels";
mkpath(dirname $profile, 0, 0755);
my %channels;
# Reads the list of channels.
sub readChannels {
return if (!-f $channelsList);
open CHANNELS, "<$channelsList" or die "cannot open `$channelsList': $!";
while (<CHANNELS>) {
chomp;
next if /^\s*\#/;
my ($url, $name) = split ' ', $_;
$url =~ s/\/*$//; # remove trailing slashes
$name = basename $url unless defined $name;
$channels{$name} = $url;
}
close CHANNELS;
}
# Writes the list of channels.
sub writeChannels {
open CHANNELS, ">$channelsList" or die "cannot open `$channelsList': $!";
foreach my $name (keys %channels) {
print CHANNELS "$channels{$name} $name\n";
}
close CHANNELS;
}
# Adds a channel.
sub addChannel {
my ($url, $name) = @_;
readChannels;
$channels{$name} = $url;
writeChannels;
}
# Remove a channel.
sub removeChannel {
my ($name) = @_;
readChannels;
delete $channels{$name};
writeChannels;
system("$Nix::Config::binDir/nix-env --profile '$profile' -e '$name'") == 0
or die "cannot remove channel `$name'";
}
# Fetch Nix expressions and pull manifests from the subscribed
# channels.
sub update {
my @channelNames = @_;
readChannels;
# Download each channel.
my $exprs = "";
foreach my $name (keys %channels) {
next if scalar @channelNames > 0 && ! grep { $_ eq $name } @{channelNames};
my $url = $channels{$name};
my $origUrl = "$url/MANIFEST";
# Check if $url is a redirect. If so, follow it now to ensure
# consistency if the redirection is changed between
# downloading the manifest and the tarball.
my $headers = `$Nix::Config::curl --silent --head '$url'`;
die "$0: unable to check `$url'\n" if $? != 0;
$headers =~ s/\r//g;
$url = $1 if $headers =~ /^Location:\s*(.*)\s*$/m;
# Check if the channel advertises a binary cache.
my $binaryCacheURL = `$Nix::Config::curl --silent '$url'/binary-cache-url`;
my $extraAttrs = "";
if ($? == 0 && $binaryCacheURL ne "") {
$extraAttrs .= "binaryCacheURL = \"$binaryCacheURL\"; ";
} else {
# No binary cache, so pull the channel manifest.
mkdir $manifestDir, 0755 unless -e $manifestDir;
die "$0: you do not have write permission to `$manifestDir'!\n" unless -W $manifestDir;
$ENV{'NIX_ORIG_URL'} = $origUrl;
system("$Nix::Config::binDir/nix-pull", "--skip-wrong-store", "$url/MANIFEST") == 0
or die "cannot pull manifest from `$url'\n";
}
# Download the channel tarball.
my $fullURL = "$url/nixexprs.tar.bz2";
print STDERR "downloading Nix expressions from `$fullURL'...\n";
my ($hash, $path) = `PRINT_PATH=1 QUIET=1 $Nix::Config::binDir/nix-prefetch-url '$fullURL'`;
die "cannot fetch `$fullURL'" if $? != 0;
chomp $path;
# If the URL contains a version number, append it to the name
# attribute (so that "nix-env -q" on the channels profile
# shows something useful).
my $cname = $name;
$cname .= $1 if basename($url) =~ /(-\d.*)$/;
$exprs .= "'f: f { name = \"$cname\"; channelName = \"$name\"; src = builtins.storePath \"$path\"; $extraAttrs }' ";
}
# Unpack the channel tarballs into the Nix store and install them
# into the channels profile.
print STDERR "unpacking channels...\n";
system("$Nix::Config::binDir/nix-env --profile '$profile' " .
"-f '<nix/unpack-channel.nix>' -i -E $exprs --quiet") == 0
or die "cannot unpack the channels";
# Make the channels appear in nix-env.
unlink $nixDefExpr if -l $nixDefExpr; # old-skool ~/.nix-defexpr
mkdir $nixDefExpr or die "cannot create directory `$nixDefExpr'" if !-e $nixDefExpr;
my $channelLink = "$nixDefExpr/channels";
unlink $channelLink; # !!! not atomic
symlink($profile, $channelLink) or die "cannot symlink `$channelLink' to `$profile'";
}
sub usageError {
print STDERR <<EOF;
Usage:
nix-channel --add URL [CHANNEL-NAME]
nix-channel --remove CHANNEL-NAME
nix-channel --list
nix-channel --update [CHANNEL-NAME...]
EOF
exit 1;
}
usageError if scalar @ARGV == 0;
while (scalar @ARGV) {
my $arg = shift @ARGV;
if ($arg eq "--add") {
usageError if scalar @ARGV < 1 || scalar @ARGV > 2;
my $url = shift @ARGV;
my $name = shift @ARGV;
unless (defined $name) {
$name = basename $url;
$name =~ s/-unstable//;
$name =~ s/-stable//;
}
addChannel($url, $name);
last;
}
if ($arg eq "--remove") {
usageError if scalar @ARGV != 1;
removeChannel(shift @ARGV);
last;
}
if ($arg eq "--list") {
usageError if scalar @ARGV != 0;
readChannels;
foreach my $name (keys %channels) {
print "$name $channels{$name}\n";
}
last;
}
elsif ($arg eq "--update") {
update(@ARGV);
last;
}
elsif ($arg eq "--help") {
usageError;
}
elsif ($arg eq "--version") {
print "nix-channel (Nix) $Nix::Config::version\n";
exit 0;
}
else {
die "unknown argument `$arg'; try `--help'";
}
}
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