in reply to Re^6: manipulating cpio archive
in thread manipulating cpio archive

I would asume that this is a bug in Archive::Cpio. The ->remove subroutine treats $archive->{list} as an array of strings (as do the examples), but it contains Archive::Cpio::File objects that don't seem to have stringification overload.

You'll likely need to rewrite the ->remove method to actually remove elements by their ->name (and raise a bug against the module, please).

The test suite only tests that the (main) module can be loaded and tests no functionality at all, so adding a test for ->remove wouldn't hurt either.

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Re^8: manipulating cpio archive
by momo33 (Beadle) on Jan 17, 2011 at 20:41 UTC
    Thank you.
    You put it more precise, but I already concluded that the code could not be right. I hope a fix will be made, there is an outstanding bug 2 years old. This code is a bit over my head.
[reply]
      As I already wrote, this code is over my head. I would like to fix the old code temporarily 
      OLD BUGGED CODE:
sub remove {
    my ($cpio, @filenames) = @_;
    $cpio->{list} or die "can't remove from nothing\n";
    my %filenames = map { $_ => 1 } @filenames;
    @{$cpio->{list}} = grep { !$filenames{$_} } @{$cpio->{list}};
}

      [download]
      with something like this 
      WRONG NEW CODE
sub remove {
    my ($cpio, @filenames) = @_;
    $cpio->{list} or die "can't remove from nothing\n";

    foreach $item (@{$cpio->{list}}) {
        foreach $file (@filesnames) {
            if ($item->{name} eq $file){
                delete @{$cpio2->{list}->{$item}};
            }  
        }
    }
    return;
}

      [download]
      How should this be done?
[reply]
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        The only flaw of the old code is that it directly compares elements from @{ $cpio->{list} } against the filenames. That is wrong because the elements in @{ $cpio->{list} } are Archive::Cpio::File objects. Instead, it should compare the elements against the ->name property. Most likely (but untested) like so:

        sub remove {
    my ($cpio, @filenames) = @_;
    $cpio->{list} or die "can't remove from nothing\n";

    # Create a lookup table of names to be removed
    my %filenames = map { $_ => 1 } @filenames;

    # This was the old, buggy code
    # @{$cpio->{list}} = grep { !$filenames{$_} } @{$cpio->{list}};

    # Remove the elements according to their name:
    @{$cpio->{list}} = grep { !$filenames{$_->name} } @{$cpio->{list}}
+;
}

        [download]
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[d/l]
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