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Re: cygwin rename util doesn't parse leading dash in expression argument correctly (thinks it is an option)

On 09/04/2014 04:17 AM, Marco Atzeri wrote:

>>> you need to tell rename that the options are ended with --
>>> $ rename -- '-fixed' '' *-fixed.flac
>>> $ ls *flac
>>> a.flac  b.flac
>> thanx for the tip, haven't had to use that since old days of  "startx
>> clientopts -- serveropts &"
>> but yet again I'm roped with having to wrap another case statement
>> around pieces of scripts for cygwin specific items (because the same
>> syntax of "rename --" doesn't work on redhat linux or another distro a
>> friend tried for me)

Then that particular version of rename is broken.  But the bug is in
that Linux distro, and you still don't have a cygwin problem.

> curious because it is the almost standard (gnu) solution in
>  most of the utilities.

Not just GNU, but POSIX.  POSIX requires that most standardized apps
(all except for a few special-cased oldies like echo) interpret -- as
the end of options, EVEN when such apps don't have any standardized
options (for example, POSIX does not require 'basename' to support any
options, yet it requires 'basename -- a' and 'basename a' to behave
identically).  POSIX also recommends that all (non-standard) apps also
honor this convention, and makes it quite easy to do so - any app built
on top of the standardized getopt() (or the GNU extension getopt_long)
will automatically handle -- correctly.

Guideline 10:
    The first -- argument that is not an option-argument should be
accepted as a delimiter indicating the end of options. Any following
arguments should be treated as operands, even if they begin with the '-'

The utilities in the Shell and Utilities volume of POSIX.1-2008 that
claim conformance to these guidelines shall conform completely to these
guidelines as if these guidelines contained the term "shall" instead of

It is recommended that all future utilities and applications use these
guidelines to enhance user portability. The fact that some historical
utilities could not be changed (to avoid breaking existing applications)
should not deter this future goal.

Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library

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