On 04/08/2016 12:15 AM, Ruediger Meier wrote: > On Friday 08 April 2016, Eric Blake wrote: >> tag 23239 notabug >> thanks >> >> On 04/07/2016 01:27 PM, Faissal Bensefia wrote: >>> Hey, >>> I stumbled across a bug in GNU coreutils' echo, if I use echo with >>> an option like -nn or -nnnnnnn it should be treated as something >>> echoable and echo "-nnnnnnn\n" but it doesn't, instead it takes it >>> as an -n argument and just doesn't echo with a newline. If I were >>> to however put a character that is not an 'n' in the long string of >>> ns it does echo it as it should. >> >> POSIX says it is not portable to use 'echo' with ANY string that >> starts with '-': >> http://pubs.opengroup.org/onlinepubs/9699919799/utilities/echo.html > > Could you please point me to the exact sentence where they mention "ANY > string that starts with "-"? I see only notes about "-n".
"
The echo utility shall not recognize the "--" argument in the manner
specified by Guideline 10 of XBD Utility Syntax Guidelines; "--" shall
be recognized as a string operand.
Implementations shall not support any options.
string
A string to be written to standard output. If the first operand is
-n, or if any of the operands contain a <backslash> character, the
results are implementation-defined.
"
Okay, so it doesn't forbid ANY string starting with -, only that such
strings are not options. But coreutils' behavior definitely falls under
the POSIX discussion I mentioned earlier:
>>
>> Also, there's a big long thread recently in the Austin Group:
>> http://thread.gmane.org/gmane.comp.standards.posix.austin.general/120
>> 97
>>
>> which concludes that POSIX is probably over-strict (by requiring
>> exactly '-n', it forbids the relatively common '-e', '-E' and even
>> '-ne' or
There's certainly a possibility that someone may propose wording to make
POSIX cater to existing implementations, and their various quirks.
>
> And probably it's also "over-strict" to forbid GNU coreutils' uniq
> options --help and --version ... which makes it even incompatible to
> GNU bash.
Coreutils complies with POSIX here:
$ /bin/echo --help | head -n1
Usage: /bin/echo [SHORT-OPTION]... [STRING]...
$ POSIXLY_CORRECT=1 /bin/echo --help
--help
When you ask for POSIX compliance, coreutils treats --help as a literal
string, exactly as required in the current wording.
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
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