Re: Code obfuscation

[John Poltorak]

On Thu, Feb 07, 2002 at 05:53:49PM +0100, Akim Demaille wrote:
> 
> | Can anyone explain what this code in autoupdate does? :-
> | 
> | 
> | my $macros = new Autom4te::XFile ("$autoconf"
> |                . " --trace AU_DEFUN:'AU:\$f:\$1'"
> |                . " --trace define:'AC:\$f:\$1'"
> |                . " --melt /dev/null |");
> | 
> | 
> | It appears to be causing the error msg:-
> | 
> | no such file or directory: /dev/null
> | 
> | on OS/2. This may be due to a bug in sh or Perl on OS/2 but it's difficult 
> | to debug. What exactly is the purpose of '/dev/null |' above, and can I 
> | try using something else instead just to get a pointer to the underlying 
> | problem?
> 
> It says `trace all the AU_DEFUN and define that are contained in
> Autoconf'.
> 
> --melt says, don't use the m4f, since if you do, then there is nothing
> to trace.  The /dev/null stands for `I don't want the definitions
> coming from ./configure.ac, I want those of the lib only, so since
> autoconf wants to trace the latter if present, tell it to trace /dev/null'.


In view of the error I'm getting, could I just create a zero length file, 
say /foo, and use:-


. " --melt    /foo |");


on the last line and get the same result? 


-- 
John