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Re: getopt reinvocation/reentrancy


Jeff Johnston wrote:
Resending as I hit the text/html button accidentally and sourceware
bounced it.  Also I have changed the content slightly.

Ralf Corsepius wrote:
On Thu, 2008-02-28 at 19:21 -0500, Gregory Pietsch wrote:

I believe that I caught the problem. In your test program, the -a and -b
switches weren't defined in your list of short options, so getopt was
returning a question mark. Fixing the testing program and applying the
latest Bug-Free(tm) getopt should work. -- Gregory

I think, some defines, you added to getopt.h with your most recent patch
should be removed. In particular:

/* macros defined by this include file */
#define NO_ARG                  0
#define REQUIRED_ARG            1
#define OPTIONAL_ARG            2
  /* The GETOPT_DATA_INITIALIZER macro is used to initialize a
statically-
     allocated variable of type struct getopt_data.  */
#define GETOPT_DATA_INITIALIZER {0,0,0,0,0}

Rationale:

- The *_ARG macros are not name-space safe and likely to clash with
other macros. If they really should be kept, then they should be
prefixed with __GETOPT_.

- All of these macros are not standardized anywhere nor am I aware about
any system providing them. I vote for removing them.


To be fair, the header file itself is non-standard; it is a glibc
extension and any application that includes it will expect at least some
non-clean macros since the glibc version of <getopt.h> declares struct
option, includes 3 macros: no_argument, required_argument,
optional_argument that are unprotected and adds the functions
getopt_long and getopt_long_only. The sys/linux version of getopt.h
defines the 3 glibc macros for compatibility and so should the
libc/include version. I'd be happy with only having the glibc names.
We could also optionally add a single underscore to the initializer
macro and two underscores to the special struct added for reentrancy to
make us essentially namespace-clean-equivalent to the glibc version.
Joel, as one of probably few getopt.h/getopt users, what do you think of
removing the old argument macros?

It doesn't bother me at all. All I wanted was the functionality of being able to reparse a set of argc/argv arguments within a single executable.

If we end up more compatible with the current glibc, then
so much the better.

--joel
I have just added the glibc macros to getopt.h.

-- Jeff J.




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Joel Sherrill, Ph.D.             Director of Research & Development
joel.sherrill@OARcorp.com        On-Line Applications Research
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