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Re: bug in cygwin's gcc/g++ getopt_long(): erroneous "ambiguous option"
- From: Corinna Vinschen <corinna-cygwin at cygwin dot com>
- To: cygwin at cygwin dot com
- Date: Tue, 13 Jan 2009 10:44:48 +0100
- Subject: Re: bug in cygwin's gcc/g++ getopt_long(): erroneous "ambiguous option"
- References: <b2c39fcb0901122149j1f3057adhaa600ea21fe7156c@mail.gmail.com>
- Reply-to: cygwin at cygwin dot com
On Jan 13 00:49, Dan Tsafrir wrote:
> Hi,
>
> When given certain long options, Cygwin's getopt_long() function
> erroneously fails on "ambiguous option". The short program below
> illustrates the problem: getopt_long() wrongfully reports the "--xy"
> option as ambiguous.
>
> Strangely, if flipping the order of the 2nd and 3rd entries in the
> options-array (by compiling the program with -DNO_BUG) the bug goes
> away, clearly demonstrating inconsistent Cygwin/getopt_long behavior.
> [...]
> #include <stdio.h>
> #include <getopt.h>
>
> const struct option lopts[] = {
> #ifdef NO_BUG
> {"xy1" , required_argument, NULL, 'a' },
> {"xy" , required_argument, NULL, 'b' },
> {"xy2" , required_argument, NULL, 'c' },
> {NULL , 0 , NULL, 0 },
> #else /* swapping order of 2nd and 3rd entries generates the bug */
> {"xy1" , required_argument, NULL, 'a' },
> {"xy2" , required_argument, NULL, 'c' },
> {"xy" , required_argument, NULL, 'b' },
> {NULL , 0 , NULL, 0 },
> #endif
> };
>
> int main()
> {
> const char* argv[] = {"./a", "--xy=1", NULL};
> int argc = 2;
> int index, c;
>
> // if NO_BUG defined, will print: "got opt=b" [OK]
> // otherwise: "a: ambiguous option -- xy" [BUG]
> if( (c = getopt_long(argc, (char**)argv, "A:B:C", lopts, &index)) != EOF )
> printf("got opt=%c\n", c);
>
> return 0;
> }
This appears to be a bug in the upstream version of getopt we're
using in Cygwin, which is the latest version from OpenBSD. I'm
looking into creating a patch for Cygwin 1.7.
Thanks for the report,
Corinna
--
Corinna Vinschen Please, send mails regarding Cygwin to
Cygwin Project Co-Leader cygwin AT cygwin DOT com
Red Hat
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