xorriso : FAILURE : Not a known command

[Leslie Zhai]

pretty cool :)


在 2017年05月31日 17:46, Thomas Schmitt 写道:
> Hi,
>
> i am now pondering over function grub2_mkisofs in Grub.pm (lacking
> much experience with Perl, i fear).
>
> Do i get it right that this code looks for the shell script variant
> of grub-mkrescue and prepares for having xorriso re-start mkisofs
> emulation after it was ended by the "--" part of "--$opt -f" ?
>
>    my $opt = '';
>    open(A, $fp) && do {
>      $opt = " -as mkisofs" if <A> =~ /^#! +\/.+sh/;
>      close A;
>    };
>    my $cmd = "$mkr --output=\"$isofilename\" $dir ".
>              join(' ', @morefiles)." --$opt -f";
>
> If the script is detected, then grub-mkrescue will get arguments
> equivalent to this pseudo shellcode:
>
>     --output="$isofilename" "$dir" -- -as mkisofs -f
>
> whereas the binary grub-mkrescue gets
>
>     --output="$isofilename" "$dir" -- -f
>
> which is wrong in case of the modern released binary version.
>
>
> Although i really do not like the gesture "-- -as mkisofs", this would be
> the place to test for the modern released binary and to treat it like the
> old shell script variant.
>
>
> My proposal is nevertheless to issue "--" only for the intermediate
> incompatible binary version. I.e. something like
>
>    my $opt = '--';
>    open(A, $fp) && do {
>      $opt = "" if <A> =~ /^#! +\/.+sh/;
>      close A;
>    };
>
>    # >>> test for modern released binary version and if so: $opt = ""
>
>    my $cmd = "$mkr --output=\"$isofilename\" $dir ".
>              join(' ', @morefiles)." $opt -f";
>
> or
>
>    my $opt = ''
>
>    # >>> test for intermediate unreleased binary version and if so: $opt = "--"
>
>    my $cmd = "$mkr --output=\"$isofilename\" $dir ".
>              join(' ', @morefiles)." $opt -f";
>
> Testing for the unreleased version might be more reliable, because this
> one is not supposed to change its signatures any more.
>
>
> I understand that the programmer of Grub.pm expected grub-mkrescue to
> go on with its incompatible CLI change, whereas GRUB developers decided
> to rather fix the unintended incompatibility before next release.
> This release has happened meanwile. So _now_ the behavior is supposed
> to be stable and deviations are to be considered bugs.
>
>
> Have a nice day :)
>
> Thomas
>

-- 
Regards,
Leslie Zhai - a LLVM hacker https://reviews.llvm.org/p/xiangzhai/