Bug#904678: dpkg-reconfigure apt-file ought to give me sources contents

[Niels Thykier <niels@thykier.net>]

Ian Jackson:
> Package: apt-file
> Version: 3.1.4
> Severity: wishlist
> 
> Ansgar has just told me about Contents-sources.gz.  Wow!  But this has
> apparently existed for years and I never knew.  This bug report is
> about the fact that it is rather harder to use than would be ideal.

Thanks for reporting this bug. :)

> The README.md.gz says
> 
>     - The "-a" option cannot be used with "source" or "udeb-$ARCH".
>       Please use the new "--index-names" option.  Remember to
>       configure APT to download the extra Contents files.
> 
> This is enough of a hint to find some things, I guess, but it would be
> nice if:
> [...]
> > Thanks,
> Ian.
> 

I can appreciate those suggestions from a user perspective.  However,
from a maintainer perspective, I do not want all the trouble and issues
of having to maintain maintscripts, debconf prompts, etc.

But we can certainly improve the situation despite of that.  As I
understand you, the primary key issue is finding the index names.  What
do you think of a "list-indices" command a la:

"""
$ apt-file list-indices
+-----------------+-----------------------------+
| Index Name (-I) | DefaultEnabled (Apt config) |
+-----------------+-----------------------------+
| deb             | <unset>                     |
| udeb            | false                       |
| deb-legacy      | <unset>                     |
| dsc             | false                       |
+-----------------+-----------------------------+
"""

(See attached patch for a prototype)

Do you think that would have solved your issue?

Thanks,
~Niels

diff --git a/apt-file b/apt-file
index a7b71fa..f8d08be 100755
--- a/apt-file
+++ b/apt-file
@@ -401,6 +401,57 @@ sub grep_package($) {
     print_winners $ret, 0;
 }
 
+sub list_indices {
+    my $iter = AptPkg::Config::Iter->new($_config);
+
+    my @indices;
+    my @headers = (
+        {
+            header => 'Index Name (-I)',
+            key => 'name'
+        },
+        {
+            header => 'DefaultEnabled (Apt config)',
+            key => 'default-enabled',
+        },
+    );
+    my @len = map { length($_->{header}) } @headers;
+    while (defined(my $key = $iter->next)) {
+        my ($type, $index_name) = @_;
+        next if $key !~ m/^Acquire::IndexTargets::(deb|deb-src)::Contents-([^:  \t]+)$/;
+        ($type, $index_name) = ($1, $2);
+        my $index =  {
+            'name' => $index_name,
+            'type' => $type,
+            'key' => $key,
+            'default-enabled' => ($_config->{"${key}::DefaultEnabled"} // '<unset>'),
+        };
+        for my $i (0..$#headers) {
+            my $header = $headers[$i];
+            my $value = $index->{$header->{'key'}};
+            $len[$i] = length($value) if length($value) > $len[$i];
+        }
+        push(@indices, $index);
+    }
+
+    my $row_delimit = sprintf("+-%s-+", join('-+-', map { '-' x $len[$_] } (0..$#headers)));
+
+    printf("%s\n", $row_delimit);
+    printf("| %s |\n", join(' | ', map { sprintf("%-*s", $len[$_], $headers[$_]{'header'}) }
+                        (0..$#headers)));
+    printf("%s\n", $row_delimit);
+    for my $index (@indices) {
+        my $name = $index->{'name'};
+        my $type = $index->{'type'};
+        my $key = $index->{'key'};
+        my $enabled = $_config->{"${key}::DefaultEnabled"} // '<unset>';
+        printf("| %s |\n", join(' | ', map {
+            sprintf("%-*s", $len[$_], $index->{$headers[$_]{'key'}})
+        } (0..$#headers)));
+    }
+    printf("%s\n", $row_delimit);
+}
+
 sub print_help {
     my $err_code = shift || 0;
 
@@ -451,6 +502,7 @@ Action:
     update                              Fetch Contents files from apt-sources.
     search|find        <pattern>        Search files in packages
     list|show          <pattern>        List files in packages
+    list-indices                        List indices configured in APT.
 EOF
     exit $err_code;
 }
@@ -665,6 +717,7 @@ sub main {
         find   => \&grep_file,
         list   => \&grep_package,
         show   => \&grep_package,
+        'list-indices' => \&list_indices,
     };
 
     if ($Conf->{help}) {