_N_GNU_nonoption_argv_flags_

_N_GNU_nonoption_argv_flags_

[Stephane Chazelas]

Hiya,

I've just come across this paragraph in the ENVIRONMENT
VARIABLES section of the GNU grep man page:

       _N_GNU_nonoption_argv_flags_
	      (Here N is grep's numeric process ID.)  If the ith
	      character of this environment variable's value is
	      1, do not consider the ith operand of grep to be
	      an option, even if it appears  to  be  one.  A
	      shell can put this variable in the environment for
	      each command it runs, specifying which operands
	      are the results of file name wildcard expansion
	      and therefore should not be treated as options.
	      This behavior is available only with the GNU C
	      library, and only when POSIXLY_CORRECT is not set.

It's news to me. Is there any plan for zsh to implement that?

-- 
Stephane

Re: _N_GNU_nonoption_argv_flags_

[Bart Schaefer]

On Sep 27,  7:42pm, Stephane Chazelas wrote:
}
}        _N_GNU_nonoption_argv_flags_
} 	      (Here N is grep's numeric process ID.)  If the ith
} 	      character of this environment variable's value is
} 	      1, do not consider the ith operand of grep to be
} 	      an option, even if it appears  to  be  one.
} 
} It's news to me. Is there any plan for zsh to implement that?

I would have to guess there are no plans, because I've never heard
it mentioned (either the variable itself, or of implementing it).

Re: _N_GNU_nonoption_argv_flags_

[Stephane CHAZELAS]

2011-09-27, 19:13(-07), Bart Schaefer:
> On Sep 27,  7:42pm, Stephane Chazelas wrote:
> }
> }        _N_GNU_nonoption_argv_flags_
> } 	      (Here N is grep's numeric process ID.)  If the ith
> } 	      character of this environment variable's value is
> } 	      1, do not consider the ith operand of grep to be
> } 	      an option, even if it appears  to  be  one.
> } 
> } It's news to me. Is there any plan for zsh to implement that?
>
> I would have to guess there are no plans, because I've never heard
> it mentioned (either the variable itself, or of implementing it).

I've just seen this in GNU bash source (GPL code):

#if 0   /* UNUSED -- it caused too many problems */
void
put_gnu_argv_flags_into_env (pid, flags_string)
     intmax_t pid;
     char *flags_string;
{
  char *dummy, *pbuf;
  int l, fl;

  pbuf = itos (pid);
  l = strlen (pbuf);

  fl = strlen (flags_string);

  dummy = (char *)xmalloc (l + fl + 30);
  dummy[0] = '_';
  strcpy (dummy + 1, pbuf);
  strcpy (dummy + 1 + l, "_GNU_nonoption_argv_flags_");
  dummy[l + 27] = '=';
  strcpy (dummy + l + 28, flags_string);

  free (pbuf);

  export_env = add_or_supercede_exported_var (dummy, 0);
}
#endif

If Chet reads us, what were the "too many problems" caused.
Where does that come from. I expect it to be an extension of GNU
getopt, but that is not mentionned in the documentation, a grep
on libc.so doesn't return anything and actually it doesn't seem
to even work here:

sh -c 'export _$$_GNU_nonoption_argv_flags_=1111; exec grep -t a'
grep: invalid option -- 't'

-- 
Stephane