> On 12/08/2017 11:38 AM, Eric B wrote: > > Hello, > > > > I am using coreutils version 8.27 on Fedora, and I don't see this fixed in > > 8.28's NEWS. > > > > $ seq 1 --help > > seq: invalid floating point argument: ‘--help’ > > Try 'seq --help' for more information.
> Interesting bug! > > > > We should be able to put the options anywhere and not necessarily before > > any > > arguments. > Yes, when possible. > > And even if not (e.g. POSIX conformance overrides,) > POSIX does say you have to write 'foo -- --help' if you want to > guarantee that --help is treated as a literal argument rather than > option, but it also says that the moment you specify '--help' (or any > other parameter starting with two dashes without the -- end-of-options > parameter), you are already in undefined territory. So we can do > whatever we want when encountering '--help' - which is part of the > reason WHY the GNU project prefers making 'foo args --help' print help > output where possible. > > --help should be handled specially to conform to the GNU coding standards. > > [1] > Yes. > But the reason that it fails is because we use getopt_long(..., > "+f:s:w") - where the leading '+' specifically requests that we NOT > allow option reordering. Why? Because 'seq' is MOST useful if it can > parse negative numbers easily. We deemed it more important to support > 'seq 2 -1 1' without requiring the user to write 'seq -- 2 -1 1' - but > in doing so, it also means that we can't reorder options, so any obvious > non-option (like '1' in your example) makes all other parameters > non-options (including '--help' in your example). > It might be possible to do a two-pass parse over argv: one that looks > just for --help (and where treating -1 as an option is a no-op), and the > second that actually parses things in order now that it knows --help is > not present. But that's a lot of code to add for a corner case, so I > won't be writing the patch; but I also won't turn it down if someone > else wants to write the patch. Hello, I've taken a stab at fixing this problem because it affects me fairly often. Instead of using a two-pass system, I check if any of the args we scan are --help or --version and bail if we see either. See attached patch. The bad side of this approach is that the -f, -s, and -w options and their associated long options aren't handled so `seq 1 -w 2 10` still shows an error. Also, it's a kludgy sort of fix, so I completely understand why you wouldn't want to include it. But at least it's a step in the right direction to give help when we can instead of an error. Chad
coreutils-seq-bug-29617.patch
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